Lithium battery configuration

[DeeJay]

Thinking of this for my Defender.
I always seem to be running close to the bone with 3x 105 amp full river batteries when camping. I run a CPAP, & 2x fridges - 1 as a freezer & lighting etc.
If I bought this setup - 4x 3.2 200 amp batteries & a renology 60 amp DC TO DC charger, would I need a separate BMS ( Battery Management System - Board) to safely operate this setup? Also, is 60 amp overkill for a 200 amp installation?

170728


I might add that the Full River batteries are getting on, so this would be close to the cost of replacements.

[drivesafe]

Hi Deejay, if you are using nearly 300Ah of AGM battery power, then you need 300Ah of lithium.

Do not take any notice of the B/S claims that you get more from a lithium battery than you will from the same size AGM battery.

[W&KO]

I’m nearly ready to have a play with building a Lithium Battery purchasing the components from a guy in AUS. More as a learning, don’t really have a need for it, maybe it’ll end up with the kids.

Been watching his videos and you need to install a BMS to protect the batteries......DC-DC will not protect your battery from overcharge along with other bits and pieces.

battery balancer , this is something else to consider......if batteries are brand new than you can opt not to install one. On receiving your batteries a quick check and you’ll know how balanced they are.

I’ll track down the links as post them, they are worth watching even if you don’t but any components off him.

I’m certainly far from an expert but keen to watch your build to learn more.

200ah is a good starting place.

[W&KO]

Not sure what your are paying for your cells.......

I’m looking at the DIY 100ah kit...

Anyways, I reckon the video ls in the link below are handy. He explain protection, balancing etc.

LiFePO4 12V 100Ah DIY Kit (https://www.fpv-power.com.au/LiFePO4-12V-100Ah-DIY-Kit)

[Blknight.aus]

the key benefit of lithium batteries in terms of power delivered (and this is where the claim of "more" comes from) is in the curve of the delivery.

normal batteries flatten at a fairly linear rate, lithiums hold voltage for a long time then drop sharply (roughly speaking)

where this comes into play is when you're at say 50% discharged and still trying to draw the same number of watts (lets go with an inverter, some kind of smart dive load likea modern fridge or DC-DC charger) W=V*A so if the voltage is dropping you have to pull more amps. A higher Amps draw means your voltage drops faster so a lithium system may appear to deliver more power for longer in a single continuous run , lithiums have a very poor "recovery" between load events. More on this after the

HOWEVER.....

roughly speaking, what they dont tell you is if you're driving a dumb load (led lights, filament bulbs, simple transistor tech) Amps= V/R so as your available voltage drops off the Amps drawn decreases. On some items like incandescent bulbs yes the light out put drops off BUT, the battery will continue to try to drive the load until it goes flat where as a lithium will just cut out more or less all of a sudden

and that

"Recovery" is that phenomenon where if you turn off a torch with alkaline batteries that are at say25% life and the lights getting a little dim, when you turn it back on 5 minutes later its at full brightness for a short period.


For my money,

if you can afford them and need to save the weight and get the maximum single draw use for your money, go lithium. If you can afford the weight and need a better load cycling capacity go lead acid and yes within the next 5-10 years that will change.

oh, also on lithiums, if you run them in series if one goes it all stops, if one drops a cell it generally stops unless you have internal parallel banking fuses

[W&KO]

the key benefit of lithium batteries in terms of power delivered (and this is where the claim of "more" comes from) is in the curve of the delivery.

normal batteries flatten at a fairly linear rate, lithiums hold voltage for a long time then drop sharply (roughly speaking)

where this comes into play is when you're at say 50% discharged and still trying to draw the same number of watts (lets go with an inverter, some kind of smart dive load likea modern fridge or DC-DC charger) W=V*A so if the voltage is dropping you have to pull more amps. A higher Amps draw means your voltage drops faster so a lithium system may appear to deliver more power for longer in a single continuous run , lithiums have a very poor "recovery" between load events. More on this after the

HOWEVER.....

roughly speaking, what they dont tell you is if you're driving a dumb load (led lights, filament bulbs, simple transistor tech) Amps= V/R so as your available voltage drops off the Amps drawn decreases. On some items like incandescent bulbs yes the light out put drops off BUT, the battery will continue to try to drive the load until it goes flat where as a lithium will just cut out more or less all of a sudden

and that

"Recovery" is that phenomenon where if you turn off a torch with alkaline batteries that are at say25% life and the lights getting a little dim, when you turn it back on 5 minutes later its at full brightness for a short period.


For my money,

if you can afford them and need to save the weight and get the maximum single draw use for your money, go lithium. If you can afford the weight and need a better load cycling capacity go lead acid and yes within the next 5-10 years that will change.

oh, also on lithiums, if you run them in series if one goes it all stops, if one drops a cell it generally stops unless you have internal parallel banking fuses

Interesting reading Dave.......

Just wondering what lithium’s you’re running and level off testing on the road/camping.

Re: poor recovery, we use ours for induction cooking anywhere between 400w to 1800w. I’ve done back to back, with short breaks, boiling water @ 1800w and the system has performed faultlessly.

Re: dumb load, haven’t experience what you have suggested, I guess I’ve size my capacity correctly. A bright light longer far out ways a slowly dulling light. If a 12v oven is classed as a dumb load than I’m also way ahead when compared to running it off the AGM in regards to oven temp.

A side note on charging, sure I now have more monitoring but I know know exactly where my SoC is at and can closely predict when I’m going to be back at 100% at my finger tips when driving....something I didn’t have on my previous AGM setup.

Re: affordability....yeah initial outlay is high but I’ve gone from watching a volt gauge all the time to pretty much to no longer worrying about capacity. I pretty much tripled my capacity for no weight gain along with ditching gas. Perfect for us for our 2 year lap, based on our shorter trips to date we have more than enough capacity to pretty much forget about our 12v systems for the duration of the trip.

For us, the upgrade has been great, set and forget.

[Blknight.aus]

Interesting reading Dave.......

Just wondering what lithium’s you’re running and level off testing on the road/camping.

Re: poor recovery, we use ours for induction cooking anywhere between 400w to 1800w. I’ve done back to back, with short breaks, boiling water @ 1800w and the system has performed faultlessly.

Re: dumb load, haven’t experience what you have suggested, I guess I’ve size my capacity correctly. A bright light longer far out ways a slowly dulling light. If a 12v oven is classed as a dumb load than I’m also way ahead when compared to running it off the AGM in regards to oven temp.

A side note on charging, sure I now have more monitoring but I know know exactly where my SoC is at and can closely predict when I’m going to be back at 100% at my finger tips when driving....something I didn’t have on my previous AGM setup.

Re: affordability....yeah initial outlay is high but I’ve gone from watching a volt gauge all the time to pretty much to no longer worrying about capacity. I pretty much tripled my capacity for no weight gain along with ditching gas. Perfect for us for our 2 year lap, based on our shorter trips to date we have more than enough capacity to pretty much forget about our 12v systems for the duration of the trip.

For us, the upgrade has been great, set and forget.


Personally I'm running some not insubstantial lead acids, why? cause I get em for free and arkies not exactly struggling for net capacity on payload. I've not yet run lithium personally and most of my experience with them comes from trying to help sort out systems that have been bought by people based on the hype. (along the lines of "why yes sir, this 50Ah lithium will work just like a 100Ah lead acid and you charge it with this here 10aDCDC" only to find that their using it like they used to use their old Lead acid so they're never fully charging the battery with short runs)

Taking some guesses you've never needed to exploit the "recovery" that you can get with lead acid with your lithium and if you've tripled your capacity and maintained the same weight of batteries I'm guessing you've got in the vicinity of 1000Ah on hand and have never taken it as a whole below the 30/40% remaining mark. Which leaves entirely unsurprising that you can run what you run the way you run it, Given that sort of operation I'm going to take a stab at about a 6 year life on your batteries (assuming they are middle of the road quality not the super exxy ones and not the cheap nasties) until they degrade to below the 70% life capacity.

I am curious as to how you're configured.

[oka374]

Eight years ago I swapped the Oka house batteries to a 400ah lithium bank made up of Winston cells instead of the existing 480ah house battery of four 120ah AGMs.
Weight went from 154 kgs to 58kgs and since then I've never had to worry about a lack of power. We run just under 1100w of solar and that is the only charging system, no input from the truck electrics at all. We do have an inbuilt 240v charger that is turned on once a fortnight when we are home and the truck is in the shed but in "use" as the fridge freezer is always on.
We have no gas and cooking is done on either a diesel cooktop or induction, heating and hot water is all diesel. Normal 240v appliances are used, electric jug, toaster, microwave, bread maker, electric blankets in cold weather plus 240v chargers for laptops and power tools. Fridge/freezer is 12v and I run a CPAP with humidifier every night on 12v, lighting is all LED and we have a myriad of USB and fag sockets for charging all the electronic devices as well as an inbuilt 12v stereo radio music player.
We sat for three weeks in a partially shaded campsite through this last wet summer and the house battery never dropped below 60% SOC despite all cooking being done on either the induction or microwave as using the diesel cooktop in hot weather tends to heat the interior quite a bit so we don't use it if it's warm.
With careful usage we can last for at least a week with minimal solar in bad weather before having to contemplate moving to a sunnier position.
A recent capacity test after the eight years of continuous use showed no decrease in the advertised capacity.
I would never go back to LA's again. If I could work out where to mount the indoor unit I would fit a 2kw domestic split aircon system as the electrics could happily cope with the extra load.

[Blknight.aus]

Eight years ago I swapped the Oka house batteries to a 400ah lithium bank made up of Winston cells instead of the existing 480ah house battery of four 120ah AGMs.
Weight went from 154 kgs to 58kgs and since then I've never had to worry about a lack of power. We run just under 1100w of solar and that is the only charging system, no input from the truck electrics at all. We do have an inbuilt 240v charger that is turned on once a fortnight when we are home and the truck is in the shed but in "use" as the fridge freezer is always on.
We have no gas and cooking is done on either a diesel cooktop or induction, heating and hot water is all diesel. Normal 240v appliances are used, electric jug, toaster, microwave, bread maker, electric blankets in cold weather plus 240v chargers for laptops and power tools. Fridge/freezer is 12v and I run a CPAP with humidifier every night on 12v, lighting is all LED and we have a myriad of USB and fag sockets for charging all the electronic devices as well as an inbuilt 12v stereo radio music player.
We sat for three weeks in a partially shaded campsite through this last wet summer and the house battery never dropped below 60% SOC despite all cooking being done on either the induction or microwave as using the diesel cooktop in hot weather tends to heat the interior quite a bit so we don't use it if it's warm.
With careful usage we can last for at least a week with minimal solar in bad weather before having to contemplate moving to a sunnier position.
A recent capacity test after the eight years of continuous use showed no decrease in the advertised capacity.
I would never go back to LA's again. If I could work out where to mount the indoor unit I would fit a 2kw domestic split aircon system as the electrics could happily cope with the extra load.

whats your battery/charger configuration and rates?

[W&KO]

Personally I'm running some not insubstantial lead acids, why? cause I get em for free and arkies not exactly struggling for net capacity on payload. I've not yet run lithium personally and most of my experience with them comes from trying to help sort out systems that have been bought by people based on the hype. (along the lines of "why yes sir, this 50Ah lithium will work just like a 100Ah lead acid and you charge it with this here 10aDCDC" only to find that their using it like they used to use their old Lead acid so they're never fully charging the battery with short runs)

Taking some guesses you've never needed to exploit the "recovery" that you can get with lead acid with your lithium and if you've tripled your capacity and maintained the same weight of batteries I'm guessing you've got in the vicinity of 1000Ah on hand and have never taken it as a whole below the 30/40% remaining mark. Which leaves entirely unsurprising that you can run what you run the way you run it, Given that sort of operation I'm going to take a stab at about a 6 year life on your batteries (assuming they are middle of the road quality not the super exxy ones and not the cheap nasties) until they degrade to below the 70% life capacity.

I am curious as to how you're configured.

No where near 1000ah,

My loose numbers for triple capacity is based on how I choose to use the batteries, and Im on the leave the starter battery out of the equation side of tie fence.

I started with a 105ah AGM which I tried not to go below 50% which gave me 50ah best case.

Installed 200ah lithium which is set to cut out at 18% which gives me ~160ah = 3 times what my AGM gave me.

Re: recovery, still confused on what you mean?

Re: life of my lithium, it only need to last for 3 years, why, it factored in to our trip.......it coming up to 1yr old and has a capacity off 203ah, no loses to date.

Config.
200ah lithium
40a DC-DC, on a bright sunny day I get ~8 ish amps from solar while driving
240w solar
2000w inverter

As mentioned earlier, it working fine and not seeing the issues raised, one less thing to worry about day too day.

[oka374]

Battery is composed of eight 200ah Winston cells in four pairs to make the battery, charging is from the 8 solar panels on the roof through a Plasmatronics PL80 solar controller.
When charged from 240v it is via a Projecta 35amp charger on the GEL setting.
The four pairs of cells are monitored by a Junsi R/C car monitor and overall monitoring is via a Victron BMV 712 which bluetooths to my phone if required.
240v is supplied by a Xantrex 1800w PSW inverter.

[W&KO]

A recent capacity test after the eight years of continuous use showed no decrease in the advertised capacity.
.

Thanks for the detailed 8 year review

Interesting no capacity loss, I’m yet to come across somebody that has quality batteries indicate any real capacity loss....That good return on investment, good chance you would have been on a second set off LA by now.

Mine only need to last 4 years (not 3 as mentioned above, couldn’t count)

[Blknight.aus]

No where near 1000ah,

My loose numbers for triple capacity is based on how I choose to use the batteries, and Im on the leave the starter battery out of the equation side of tie fence.

I started with a 105ah AGM which I tried not to go below 50% which gave me 50ah best case.

Installed 200ah lithium which is set to cut out at 18% which gives me ~160ah = 3 times what my AGM gave me.

Re: recovery, still confused on what you mean?

Re: life of my lithium, it only need to last for 3 years, why, it factored in to our trip.......it coming up to 1yr old and has a capacity off 203ah, no loses to date.

Config.
200ah lithium
40a DC-DC, on a bright sunny day I get ~8 ish amps from solar while driving
240w solar
2000w inverter

As mentioned earlier, it working fine and not seeing the issues raised, one less thing to worry about day too day.


overall capacity isnt based on how you use it, its what youve got, how you use it gives up how long you can make it last.

I'm assuming that while driving (and charging) the DCDC is pulling what it can from flat panels on the roof and then making up the shortfall off the alternator..

your usage rate about equals mine but I'm running 220AH of LA (2x115ha 1200CCA n120(ish) truck batteries in parallel) but only 90ishW of solar for maintenance charging and the alternator charges between stops on the run. However I dont have any critical support stuff on the batteries like a Cpap But I can dump over 2000 amps for short periods, my nominal loads (excluding light weight things like led lights, gps and radio)

1. fridge
2. winch
3. electric blankets (girlfriend has [I]no/I] metabolism or body fat)
4. run the diesel heater.
5. run the invertor for the compressor

almost all of that is short load time followed by a period of "rest" during which the battery can "recover"

this lays out the concept pretty well.

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.534.6206&rep=rep1&type=pdf

[W&KO]

overall capacity isnt based on how you use it, its what youve got, how you use it gives up how long you can make it last.

I'm assuming that while driving (and charging) the DCDC is pulling what it can from flat panels on the roof and then making up the shortfall off the alternator..

your usage rate about equals mine but I'm running 220AH of LA (2x115ha 1200CCA n120(ish) truck batteries in parallel) but only 90ishW of solar for maintenance charging and the alternator charges between stops on the run. However I dont have any critical support stuff on the batteries like a Cpap But I can dump over 2000 amps for short periods, my nominal loads (excluding light weight things like led lights, gps and radio)

1. fridge
2. winch
3. electric blankets (girlfriend has [I]no/I] metabolism or body fat)
4. run the diesel heater.
5. run the invertor for the compressor

almost all of that is short load time followed by a period of "rest" during which the battery can "recover"

this lays out the concept pretty well.

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.534.6206&rep=rep1&type=pdf

Re: usage, I only used 50% and didn’t touch what other capacity I may have had therefore I don’t count it in my cals....same as with lithium, I only use to 18%. For either setup, if/when I got close to my allowed percentage I re-charge.

Re: charging the lithium, I get full 40amps from DC-DC along with whatever solar is available, I run a separate solar controller rather than running the solar though the DC-DC which means battery will accept charge from both sources. On a good day I get around 50ah into battery while driving, if I’m not lucky with sunshine than I get a guaranteed 40amps......does starts to back off when nearing 100%.

I’m yet to not be at 100% when arriving at next campsite.

[W&KO]

Me thinks too many over complicate, over think lithium.....it’s really not that much different to the old school lead acid batteries systems

Back to the OP question as we’ve digressed about helping him with a DIY build.

The page I linked above I believe they also have a 280ah cell available to DIY as a kit that’s not listed on the website. If he does he will also have a box with two terminals on the top.

[DeeJay]

Not sure what your are paying for your cells.......

I’m looking at the DIY 100ah kit...

Anyways, I reckon the video ls in the link below are handy. He explain protection, balancing etc.

LiFePO4 12V 100Ah DIY Kit (https://www.fpv-power.com.au/LiFePO4-12V-100Ah-DIY-Kit)

The 200ah Lithium I posted about cost $700 plus whatever for a BMS.
I have "T" brand lithium - from Lanplus- for my E bike & am very impressed. They also have 100 amp at a reasonable price, sorry to say a lot less than building one as per your link. The big ?? is if quality is the same, or the same as my E Bike. I'm still pondering & researching, so thanks for the advice about the BMS.

12V_100AH_LFP (lanplus.com.au) (https://www.lanplus.com.au/lifepo4-lithium-batteries?product_id=524)

[W&KO]

The 200ah Lithium I posted about cost $700 plus whatever for a BMS.
I have "T" brand lithium - from Lanplus- for my E bike & am very impressed. They also have 100 amp at a reasonable price, sorry to say a lot less than building one as per your link. The big ?? is if quality is the same, or the same as my E Bike. I'm still pondering & researching, so thanks for the advice about the BMS.

12V_100AH_LFP (lanplus.com.au) (https://www.lanplus.com.au/lifepo4-lithium-batteries?product_id=524)

Thanks for the reply yes that a good price for 200.

Mainly post the link for the videos which I found helpful.

Keep us posted on your build

[DiscoMick]

Interesting experiences.
We are looking at fitting a 200Amp Enerdrive lithium battery and management-charging system to our caravan.
There are cheaper lithiums around, but the advice I'm getting is that will be roughly equivalent to 300 Amps of AGM and the Enerdrive setup is high quality and optimised.
The 200 Amps of AGM in our camper trailer have done the job well, so I figure the 200 Amps of lithium should be fine. We're only running a fridge-freezer, LED lights and the caravan will have a 12-volt TV.
What do you think?

[Blknight.aus]

Interesting experiences.
We are looking at fitting a 200Amp Enerdrive lithium battery and management-charging system to our caravan.
There are cheaper lithiums around, but the advice I'm getting is that will be roughly equivalent to 300 Amps of AGM and the Enerdrive setup is high quality and optimised.
The 200 Amps of AGM in our camper trailer have done the job well, so I figure the 200 Amps of lithium should be fine. We're only running a fridge-freezer, LED lights and the caravan will have a 12-volt TV.
What do you think?

Overkill, but then, thats the best kind.


One thing I've really wanted to get to going to town on with lithiums is how they hold up on partial charge cycles, I know how the smaller units hold up but I'm curious as to the scalability of it.

[drivesafe]

200Amp Enerdrive lithium battery will be roughly equivalent to 300 Amps of AGM
Hi Mick and this is nothing but advertising B/S.
All lead acid deep cycle batteries used in RV situations, have been able to be safely cycled down to 20% and many of the newer ones can be cycled down to 0%.

So 200Ah of lithium batteries is going to be the equivalent to 240Ah of older type lead acid deep cycle batteries and are the same as 200Ah of newer type lead acid deep cycle batteries.

[Silenceisgolden]

As I understand it, sulphation occurs in lead acid batteries any time they are not fully charged. Sulphation is what kills lead acid batteries. The deeper the discharge, the greater the rate of sulphation. Charging reverses the sulphation but not completely. The deeper the discharge, the less reversible is the sulphation. The longer the battery is discharged, the less reversible is the sulphation.
Thus for maximum battery life, both the depth of discharge and the period of discharge should be minimised.

LiFePO4 cells do not have this problem, and thus can be more deeply discharged without reducing their life as much as with lead-acid.

[drivesafe]

The deeper the discharge, the greater the rate of sulphation.
This statement is not correct.

You can discharge any deep cycle battery down to the manufacturers stated limit and recharge the battery to its fully charged state.

Many batteries are used this way, for example, those used in golf buggies and electric folk lifts, and they do not loose capacity just because they have been deeply discharged.

Theoretically, if you discharge any battery below 75% SoC and LEAVE IT FOR SOME TIME, then sulphation will occur, but only if you leave the battery in a discharged state for more than 24 hours.

While a battery is under load or being charged, there is a chemical reaction occuring in the battery.

While this chemical reaction is occurring, no sulphation will occur, and the chemical reaction in a battery can take up to 24 hour to stop, after charging or discharging has been removed.

Also, leaving a battery in a fully charged state for long periods of time between charges will also allow a battery to slowly sulphate, because all lead acid batteries SLOWLY self discharge.

Sulphation can only occur if a battery is allowed to settle and then left for some time, it does not occur in batteries that are continually cycled.

[DiscoMick]

Earlier it was mentioned running a CPAP. I have a portable CPAP which came with a lithium battery with enough capacity to power it for 2 nights. I recharge it during the day when the house is making plenty of solar. Being portable I can take it everywhere, even on planes. This might be a way to cut your usage.

[Salt grinder]

Tim, I would like to hear your thoughts more deeply on this discussion and also that of others, with knowledge of the topic.

Whilst we embrace this new technology and can get swept up in the hype, what are we really getting for our $$$ and sales hype ?
As I understand it, the Lithiums do have definite advantages in (generally) being able to run down to extremely low levels and be fully recovered which is great.
Certainly in uses like torches etc and other rechargeable batteries where we can avoid having to throw away used product after its limited life, it's good.

But let's stick to what I want to know is fact from sales hype and the new you-beaut follow the mob toy. It's, to me, about the battery construction and ability to survive the purpose for which it's manufactured.
A battery in hard working machinery like a tractor, truck etc exposed to continuous jarring and hard movement, corrugations etc has to be internally stronger than one used in more passive conditions.
Why is a marine battery different to a family car battery, for instance.

So, how is a 12v lithium battery constructed and is it internally more stable than other lead acids, calcium or what ever they claim it is. Being cynical, I see a lot of batteries that look to have the same case construction
with just a different label slapped on the outside.

JohnC

[W&KO]

Tim, I would like to hear your thoughts more deeply on this discussion and also that of others, with knowledge of the topic.

Whilst we embrace this new technology and can get swept up in the hype, what are we really getting for our $$$ and sales hype ?
As I understand it, the Lithiums do have definite advantages in (generally) being able to run down to extremely low levels and be fully recovered which is great.
Certainly in uses like torches etc and other rechargeable batteries where we can avoid having to throw away used product after its limited life, it's good.

But let's stick to what I want to know is fact from sales hype and the new you-beaut follow the mob toy. It's, to me, about the battery construction and ability to survive the purpose for which it's manufactured.
A battery in hard working machinery like a tractor, truck etc exposed to continuous jarring and hard movement, corrugations etc has to be internally stronger than one used in more passive conditions.
Why is a marine battery different to a family car battery, for instance.

So, how is a 12v lithium battery constructed and is it internally more stable than other lead acids, calcium or what ever they claim it is. Being cynical, I see a lot of batteries that look to have the same case construction
with just a different label slapped on the outside.

JohnC

When we choose to upgrade I didn’t think there was any sales hype or felt the need to follow the mob. There is enough solid info out there along with thousands of installations that are working fine for what the end user wants. Go with the ‘brand’ name batteries and it’s a pretty safe bet.

Lithium to me is just another option depending on ones needs. Will suit some but not others.

For us it was the only way to go.......it’s factored into our budget for our two year trip and the install only needs to last 4 years and it’s done it’s job....although fully expect it to be powering on well after.

[drivesafe]

Tim, I would like to hear your thoughts more deeply on this discussion and also that of others, with knowledge of the topic.

Whilst we embrace this new technology and can get swept up in the hype, what are we really getting for our $$$ and sales hype ?
As I understand it, the Lithiums do have definite advantages in (generally) being able to run down to extremely low levels and be fully recovered which is great.
Certainly in uses like torches etc and other rechargeable batteries where we can avoid having to throw away used product after its limited life, it's good.

But let's stick to what I want to know is fact from sales hype and the new you-beaut follow the mob toy. It's, to me, about the battery construction and ability to survive the purpose for which it's manufactured.
A battery in hard working machinery like a tractor, truck etc exposed to continuous jarring and hard movement, corrugations etc has to be internally stronger than one used in more passive conditions.
Why is a marine battery different to a family car battery, for instance.

So, how is a 12v lithium battery constructed and is it internally more stable than other lead acids, calcium or what ever they claim it is. Being cynical, I see a lot of batteries that look to have the same case construction
with just a different label slapped on the outside.

JohnCHi John, I am flat out but will give you a reply in the next few days.

Your questions are important ones to answer, as the lithium battery market is a mine field and you do need some basics to protect your pocket.

[Blknight.aus]

one of the hardest things to get right when installing a lithium setup is dealing with charging them.

They dont like being hard charged, if youve got a discharged lithium (not to the point its cut out) and try charging it straight off a large alternator the alternator will deliver too much current and cook up the lithium battery.


one thing I have always wanted to experiment with is to match the alternator to the peak charge rating of a lithium bank and let that provide source current. its not quite as simple as putting a 35a alternator onto a bank that can handle a 35a charge because as you load up an alternator as it struggles to make voltage the amps go up to maintain maximum rated watts...

but back of the napkin maths suggests that if you have a lithium pack rated to 40a charge peak you should be ok to directly run that off of a 30a alternator thats been tweaked to peak at 14.2v (or whatever your flavor of lithium likes for a peak charge voltage)

[W&KO]

one of the hardest things to get right when installing a lithium setup is dealing with charging them.
)

For the majority of lithium battery users (caravan, touring) charging is straight forward.......between a DC-DC and the batteries BMS it all looks after itself.

Unless off course you have a unique setup or need....than it’s easy peezy, install, set, forget.

[Blknight.aus]

For the majority of lithium battery users (caravan, touring) charging is straight forward.......between a DC-DC and the batteries BMS it all looks after itself.

Unless off course you have a unique setup or need....than it’s easy peezy, install, set, forget.

IF you're buying a complete ready to go system that comes prematched from the one supplier yes, but once you're out of that environment it can get "sketchy" It is getting a lot easier now with many reputable suppliers providing a lithium setting on their chargers and DC/DC systems, hell I even got a tip from my local jaycar guy to check out the website of the company that provides their older chargers for a bulletin that describes what settings to use if you want to use their older non lithium compatible regulators on a lithium bank (which is loosely translated, "Dont unless the charge capacity of the bank is higher than the rated output of the regulator" and then some maths on how to set the float, bulk and absorbsion charge voltage limits)

I'm waiting on the newer format of batteries to come out at a reasonable price which perform similarly to normal led batteries as far as hooking them up is concerned as all of the management is built into the battery.
similar to this one in the lnk below but with the ports on the top of the battery that allow BMS linking for when you connect them in series and a trickle charge jack that allow you to charge them very slowly if you over discharge them

reBel Batteries - 12V 100A LiFePO4 Tear Down - Inside a Lithium Iron Phosphate Battery - YouTube (https://www.youtube.com/watch?v=zJsMRCzfOCA&ab_channel=reBelBatteries)

[Geedublya]

A video from Stephan who used to frequent this site with a good rundown on how he is using lithium.


https://www.youtube.com/watch?v=FbStDC-7Q9E&t=10s

[W&KO]

IF you're buying a complete ready to go system that comes prematched from the one supplier yes, but once you're out of that environment it can get "sketchy" [/url]

this is what the OP is doing, he is out of the normal environment, I don’t believe it to be sketchy.

My next battery will be a DIY.......

Select batteries with spec that suits use
Select cell balancer
Select BMS
Select charger
Assemble.

[W&KO]

A video from Stephan who used to frequent this site with a good rundown on how he is using lithium.


https://www.youtube.com/watch?v=FbStDC-7Q9E&t=10s

His latest video compares DC-DC, I run Enerdrive and made a comment in his video which he replied to.

[drivesafe]

Go with the ‘brand’ name batteries and it’s a pretty safe bet.
That is actually very poor advice.


If you check out the specs for many of the so-called Name Brands, many have specs no better and some are even worse than cheapo lithium batteries.

Forget brand names and look at the specific specs for each brand of lithium battery.

Dave’s suggestion that the lithium battery market is “sketchy” is spot on the money.

The link to the Tear Down battery is a perfect example of why you need to know and UNDERSTAND what each lithium battery’s specs mean.

I personally would not buy that brand of lithium battery, because the specs are “sketchy” and don’t give anywhere near the relevant details needed, to be able to determine how good ( or bad ) that battery is.

Then to make matters worse, they use deliberately misleading lead acid battery info as a means of trying to make their lithium battery look better than what I suspect it real is.

The best thing anybody can do, before buying Lithium batteries, is learn what the specs mean for lithium batteries and then compare the specs for each brand of battery you are looking at.

[Blknight.aus]

A video from Stephan who used to frequent this site with a good rundown on how he is using lithium.


https://www.youtube.com/watch?v=FbStDC-7Q9E&t=10s

pay attention to this bit for about 2 minutes.. He mentions changing alternators and setting different charge rates.

This LiFePo4 Starter Battery Changed How I Travel! Lithium Under Bonnet Setup - 12 Month Review - YouTube (https://youtu.be/FbStDC-7Q9E?t=346)

here hes included the overall spec summary of various batteries highlighting the DCS unit which by all accounts other than overall price is an absolute LA killer. Although compared to the Actual DCS site is a little more generous than the current DCS specs. Hes also mentioned to be cautious about cheap batteries that are not up to high current work

This LiFePo4 Starter Battery Changed How I Travel! Lithium Under Bonnet Setup - 12 Month Review - YouTube (https://youtu.be/FbStDC-7Q9E?t=547)
and the DCS specs (although dont watch the snake oil vids on the DCS page they're somewhat not as honest as they might otherwise be)
DCS 12V 100AH (LITHIUM) (https://www.deepcyclesystems.com.au/product/dcs-12v-100ah-lithium-ion/)

Not long after that he shows a winching demo, hes pulling 250+Amps (measured on a clamp meter) and while hes only showing 1 battery on the monitor its not hitting 120+ amps its showing between 80 and 105 amps.

which leads me to assume that he's got the engine sitting at low idle as well. This highlights one of the issues of using a lower rate alternator and higher capacity batteries. The batteries are picking up the lions share of the work until they pull down to the point where the alternator can do its job, with a 200A alternator running at full output in this case you'd only expect to see about 20-30 amps on the batteries.


next he covers off on battery construction.

This LiFePo4 Starter Battery Changed How I Travel! Lithium Under Bonnet Setup - 12 Month Review - YouTube (https://youtu.be/FbStDC-7Q9E?t=804)

and hits an overall summary.

having sat through his video spending a fair bit of time flicking and pausing while I go and check various bits of info, noting that he makes mention that hes only in it for a year and still testing, and he mentions all the usual "check with" and "in most cases" that I would throw around there are 3 reservations I have before I would outright recommend throwing a DCS12v100A lithium in as the primary battery.

1. the max draw is not enough on a single battery to crank a diesel (*) or drive a winch (based on the DCS website info)
2. They have a float voltage that is lower than most nominal alternator outputs
3. they have a recommended and maximum charge amps rate that is lower than most modern alternator outputs.

(*)modern diesels need turning for longer while the various computers work out where the engine is, fuel pressures to be correct, oil pressure etc before they start compared to an older mechanical diesel where under normalish conditions its a case of glow and go and on a good day a start is had within 4 turns of the crank)

putting one in as a second battery behind a good high current DC/DC unit OR a moderate DC/DC with an additional solar charger, That I would recommend in a heart beat IF you can afford the $1300. (the assumption of the DC/DC and solar is a freebie for this installation as you were probably going to get them anyway)
Putting 2 in and running them in permanent parallel with a dedicated specification alternator, I would also recommend IF you can afford approximately $3k for the 2 batteries and the alternator.

[DeeJay]

Earlier it was mentioned running a CPAP. I have a portable CPAP which came with a lithium battery with enough capacity to power it for 2 nights. I recharge it during the day when the house is making plenty of solar. Being portable I can take it everywhere, even on planes. This might be a way to cut your usage.

I would be interested in the quoted a/h usage of that unit, as my "home" CPAP runs through a 12v transformer so I could use it camping- with a direct lead & fuse from the batteries. The stated 12v usage (I assume with humidifier working) is 6.5 a/h.
I experimented with the "camping" CPAP & using a clamp meter, found it uses between 2.5-3.2 amps/hr as you can disable the humidifier- which in the Vic high plains, I don't seem to need.
Next step is to buy a correct lead for the home CPAP & see what the usage is & if I can disable the humidifier as its one of those automatic - ie $1500 - ones[tonguewink] as 6.5 ah is a lot.

[drivesafe]

Earlier it was mentioned running a CPAP. I have a portable CPAP which came with a lithium battery with enough capacity to power it for 2 nights. I recharge it during the day when the house is making plenty of solar. Being portable I can take it everywhere, even on planes. This might be a way to cut your usage.
Hi Mick, what was the size of the lithium battery?

[Splash]

Thinking of this for my Defender.
I always seem to be running close to the bone with 3x 105 amp full river batteries when camping. I run a CPAP, & 2x fridges - 1 as a freezer & lighting etc.
If I bought this setup - 4x 3.2 200 amp batteries & a renology 60 amp DC TO DC charger, would I need a separate BMS ( Battery Management System - Board) to safely operate this setup? Also, is 60 amp overkill for a 200 amp installation?

170728


I might add that the Full River batteries are getting on, so this would be close to the cost of replacements.


Under no circumstances run the Lithium batteries without a Battery Management System. Lithium individual cells will go out of balance and fail in a very short time without the BMS

A better option is to buy 3 X 100AHr Lithium 12 volt batteries with inbuilt BMS which will drop straight into your Lead Acid set-up. Basically a direct replacement for the Lead Acid Batteries. Physical size about the same, weight about a third, as the Lead Acid's and effectively three times the useful long life capacity.