Swapping to lithium

[Ranga]

My AGM in the slide-on has expired (8+ years ain't a bad run), so yet again I'm considering going lithium. My set up is as follows:

• vehicle has an AGM auxiliary being charged from the alternator (with an isolator)
• slide-on has (had!) an AGM, 150W solar panel and Morningstar MPPT solar regulator
• [heavy duty connection using Anderson plugs between the vehicle AGM and the slide-on AGM

Getting another AGM is a straight swap, and if I can get 8 years out of another one I might just do that. I'm also considering adding a large inverter to run an electric induction hotplate. Before I stick with AGM, I thought I should get some advice on what components I would need (include brand/model/supplier) to swap to lithium to make an informed choice. Price is obviously a factor, weight and physical size not so much.

Anyone out there care to have make a suggestion?

[philandmickey]

Hi
I have a very similar set up to you.
But I have Ctek DCDC charger that has a solar input. and a 300w solar panel on the roof.
I had 2 x 100amp agms in the camper and swapped them for an Itech I120X.
This gives me the same capapcity (as it can use 80% capacity).
But the big advantage for me was the AGM's weighed 80kg and the lithium 13kg.
It's been fitted about a year now and so far so good.

Cheers
Phil

[W&KO]

If you’re considering induction cooktop the more storage you have the better. To be comfortable you would need at least two AGM’s or switch to a lithium. Keep in mind you need enough up you’re sleeve to run the fridge overnight and maybe some capacity in the morning.

For 2A when the sun rises we regularly see remaining percentage dipping into the 70’s. Lowest to date is 68%. This is on a 200amp/hr battery. So up to 64amp/hrs.

Brands...there is gear to suit all budgets, from super cheap to super expensive.

There is a guy on FB Van Life page testing a few of the cheaper brands, sorting the duds from the good. He is doing capacity testing and these are performing around or above stated amp/hrs.

LiFePo4 Lithium Batteries

My install is in the upper end pricing with comments

Enerdrive
DC-DC 40+ (check recommended charge rate for battery, most have solar input check if it preferences a charge source, I have an Anderson plug connected to the solar input for a blanket if required, these DC-DC’s seem popular even on budget builds)
2000w inverter (check max. Current draw from battery, we run our induction on 1800w pulling 170amps)
200amp/hr Battery
Low voltage cut out (I wouldn’t run my lithium to 0%)
Remote display (handy)

Victron 100/30 solar regulator. (I run this so battery can take charge from solar and alternator while driving).

2 x 120w semi flex solar. (Not 100% sold on semi flex)

[PWat]

I’ve recently installed a system in my slide-on camper. It hasn’t left the driveway yet but seems to be working in test mode! I calculated I needed 80AHrs usable capacity in order to run my fridge and a few lights for 3 consecutive rainy days.

I bought a 100AHr Enerdrive Lithium:
- Lithium because of space (1 battery vs 2), weight and lifetime;
- Enerdrive due to battery type (prismatic) and brand name. (We were also thrown some Covid-cash from the government when I was deciding what to buy!)
- The more expensive batteries also have a Bluetooth interface so you can check the charge state and current charge rate/consumption. (AGM batteries and cheaper need an external charge monitor.)

I chose the Redarc 25Amp charger rather that the Enerdrive 40Amp:
- It will charge simultaneously from the car and solar. (The Enerdrive and most other units just switch.)
- It’s physically smaller and lighter;
- 25Amps matches my solar panels;
- Downside is that it’s a bit more expensive;
- One advantage of Enerdrive is that you can drive it from household solar panels (which run at a higher voltage). You can get second-hand panels for almost nothing but they are very heavy.


Something to check: your existing charger may have a Lithium setting.

Hope this helps....

[W&KO]

I’ve recently installed a system in my slide-on camper. It hasn’t left the driveway yet but seems to be working in test mode! I calculated I needed 80AHrs usable capacity in order to run my fridge and a few lights for 3 consecutive rainy days.

I bought a 100AHr Enerdrive Lithium:
- Lithium because of space (1 battery vs 2), weight and lifetime;
- Enerdrive due to battery type (prismatic) and brand name. (We were also thrown some Covid-cash from the government when I was deciding what to buy!)
- The more expensive batteries also have a Bluetooth interface so you can check the charge state and current charge rate/consumption. (AGM batteries and cheaper need an external charge monitor.)

I chose the Redarc 25Amp charger rather that the Enerdrive 40Amp:
- It will charge simultaneously from the car and solar. (The Enerdrive and most other units just switch.)
- It’s physically smaller and lighter;
- 25Amps matches my solar panels;
- Downside is that it’s a bit more expensive;
- One advantage of Enerdrive is that you can drive it from household solar panels (which run at a higher voltage). You can get second-hand panels for almost nothing but they are very heavy.


Something to check: your existing charger may have a Lithium setting.

Hope this helps....

Who much solar are you running?

I notice the recommended charge rate of the 100amp/hr is 33amp with a max. of 50amps for 30min.

Maybe something to consider

[PWat]

Who much solar are you running?

I notice the recommended charge rate of the 100amp/hr is 33amp with a max. of 50amps for 30min.

Maybe something to consider

2 x 150w --> 25A

I only installed them a couple of weeks ago and the battery was charging at up to 22 amps which I was pretty happy with given it was mid-afternoon sun and the panels were horizontal.

I bought these - cost effective and not as heavy as some: 12V 150W Monocrystalline Solar Panel | Jaycar Electronics

[W&KO]

2 x 150w --> 25A

I only installed them a couple of weeks ago and the battery was charging at up to 22 amps which I was pretty happy with given it was mid-afternoon sun and the panels were horizontal.

I bought these - cost effective and not as heavy as some: 12V 150W Monocrystalline Solar Panel | Jaycar Electronics

Thanks...

I was crunching the number on recommended charge rate to max charge rate. More so for my knowledge against selecting items.

Cheers

[drivesafe]

My AGM in the slide-on has expired (8+ years ain't a bad run), so yet again I'm considering going lithium. My set up is as follows:

• vehicle has an AGM auxiliary being charged from the alternator (with an isolator)
• slide-on has (had!) an AGM, 150W solar panel and Morningstar MPPT solar regulator
• [heavy duty connection using Anderson plugs between the vehicle AGM and the slide-on AGM

Getting another AGM is a straight swap, and if I can get 8 years out of another one I might just do that. I'm also considering adding a large inverter to run an electric induction hotplate. Before I stick with AGM, I thought I should get some advice on what components I would need (include brand/model/supplier) to swap to lithium to make an informed choice. Price is obviously a factor, weight and physical size not so much.

Anyone out there care to have make a suggestion?

Hi Ranga, what size AGM are you using right now?

Besides the obvious, is there any special reason for wanting to run an induction hotplate?

[DeanoH]

" Oils ain't oils Sol", or in this case there's lithium batterys and there's lithium batterys. A quick look at eBay will show that a typical 100 ah will set you back somewhere between $350 and $1200. It's a real lithium battery swamp out there and it's full of crocodiles .

I managed to wade through this swamp last year when I upgraded the Oka house battery from AGM to LiFePO4. Selecting a good lithium battery over a not so good one can be difficult but in the end the initial selection factor I used was weight, not very technical but it became clear (to me) that the better batterys weighed in around 12 Kg and had a warranty of between 3 and 5 years (from a reputable dealer) and the 'not so good' batterys weighed in substantially less than this, some as little as 6 Kg with a warranty of 12 months or so from lesser known vendors.

It may be that some manufacturers have come up with a brilliant battery design that needs only half the mass of active ingredient as other lithium batterys and gladly pass this substantial cost saving on to the consumer, but on the other hand it's possible they're just cheap crap. Seriously though, you can do a lot worse than using battery mass as a starting point when selecting a new lithium battery.

A couple of other points to ponder. A typical induction cook top is rated at 2000 watts or around 160 amps at 12 volts of battery current into a suitable inverter assuming no losses so best case at full power. Unfortunately your typical lithium 100 ah battery cannot supply this current so you'd need at least two or 200 ah worth. If you plan on using the same batterys to power an electric winch, forget it as a typical electric winch (4WD Supastore 12000 lb) draws 430 amps at full load. Don't forget your starter motor here as it can draw in excess of 400 amps also depending on the vehicle.

A lithium compatible DC-DC converter is a good idea for lithium battery charging as it a/. provides isolation of an auxiliary (lithium) battery from the vehicle battery, b/. provides optimal charging and c/. limits lithium battery charge current which can be very important in preventing alternator/wiring failure.

The point I'm trying to make here is that upgrading to lithium from AGM may not be as simple as just plugging in a LiFePO4 100 ah replacement battery.

In my case I retained a lead acid vehicle/start battery and connected this via a DC-DC converter to the lithium house battery (2X100ah LiFePO4). The solar is fed by a separate solar reg with its own LiFePO4 charging profile.


Deano

[drivesafe]

Hi folks and this is a big, BIG warning to those looking at buying lithium batteries.

You need to make yourselves aware of at least the basic lithium battery specifications to look for, before laying out hard earned cash for these products.

Nearly 10 years ago, I was LUCKY to be asked to test a couple of brands of lithium batteries for a company I do a lot of business with.

At the time, I made it quite clear that I knew next to nothing about Lithium batteries or how to go about testing them.

They made it a point of letting me know that they were only too happy to let me learn about lithium batteries on the run, as it was a learning curve for them as well, because they wanted to source a decent brand to supply their customers with.

To this end, and while I do not rate myself as an expert of any form when it comes to lithium batteries, but I have gained enough knowledge about them to know when a lithium battery is of some quality and when they are nothing but cheap junk.

Back to the thread and while it has been some time since I last looked at what lithium batteries are available, so after reading Deano’s post, I decided it was time once again to see what was out there.

I could not believe how pathetic some of the “well known” brands were.

Two in particular stuck out, and this is where having a basic idea of lithium battery spics comes into play.

Both of these brands were being touted as being 100Ah batteries, but they were being marketed as only being able to provide 2,000 cycle down to 20%.

One of the advantages of using Lithium batteries is that they are “supposed to” be abled to cycled down to 0%.

So for a starter, these well known brands of 100Ah lithium batteries were actually only 80Ah batteries.

While you can take this as a plug for my brand of lithium batteries, but the intention is to demonstrate the differences, as mine come with specs stating they can be cycled down to 0% 3,000 times.

This means the DEARER well known batteries have a total throughput of 160,000 amperes compared to my battery’s 300,000.

The DEARER batteries had a maximum continuous discharge rate of 100 amps but then this was only guaranteed for 30 minutes, while mine can be full discharged at 100 amps to 0% capacity.

Again, you need to be able to know what the specs mean when looking at lithium batteries, and the specs to be aware of are the cycle rates and maximum discharge currents.