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drivesafe
29th May 2021, 04:11 PM
How do you select the best value Lithium Battery?

A heads-up on my connection to lithium batteries.

I am “NOT” an expert on lithium batteries but I have been working with them for just over a decade now.

This included testing a large number of them and taking a couple of lithium batteries to the point where they were damaged, as requested by the supplier, so that they had a genuine idea of what their batteries could safely tolerate.

While I no longer sell lithium batteries, I still have a number of lithium batteries in my workshop, and I still carry out a fair amount of testing and I use these batteries as the Set-Point to compare with other lithium batteries.

From experience, so called “NAME” brands mean nothing, and neither does comparing Price vs Amp Hours. A common practice but falls short of anything meaningful.

The following is how I sort out good from not so good Lithium batteries and whether you follow this is completely up to you as the buyer.

First and foremost, get the specs for the battery. If there are no specs, or very limited specs, I personally avoid those batteries.

The specs need to include :-

“USABLE” Ah ( Amp Hours ) not just the total Ah.

Cycle rate to the lowest recommended DoD ( Depth of Discharge )

Optimum and maximum charge current.

Optimum and maximum “CONTINUOUS” discharge current.

Operating temperature range. While not as important as this should not be a problem in Australia but it is still a good idea to be sure the battery will be usable in RV conditions.

I also make sure the warranty period is no less than 3 years.

I have no intentions of using a lithium battery as a cranking battery, and nor do I intend to put one in an engine bay, and while this is a personal choice, it also governs where the battery is to be used.

My choice for seeing what value for money a given lithium battery is, is to compare Throughput to cost.

To do this, first get the cycle rate at the lowest DoD and multiply this by the amp hours at that DoD.

For instance, if a battery specs for a 100Ah lithium battery state that that particular battery can be cycled down to 80% DoD 2,000 time, then the Throughput for that battery 80 x 2,000, or 160,000 AMPERES.

If this battery cost $850, divide the 160,000 by 850 and you get the USABLE amperes per dollar, over the lifespan of the battery.


Here are some examples.


A Fusion V-LFP-12-100, a 100Ah Lithium battery can be cycles down to 100% DoD 1,600 times and with a cost of $998, this battery has a USABLE amperes per dollar value of 160.


A Solarking CB-100-12-100, another 100Ah Lithium battery can be cycles down to 100% DoD, 2,000 times and can be bought for $588, giving this battery has a USABLE amperes per dollar value of 340.


An Enerdrive EPL-100-12VLITE, another 100Ah Lithium battery can be cycles down to 80% DoD, 2,000 times and can be bought for $869, giving this battery has a USABLE amperes per dollar value of 178.


A Redarc LBAT12100, another 100Ah Lithium battery can be cycles down to 80% DoD, 2,000 times and can be bought for $1,498, giving this battery has a USABLE amperes per dollar value of 107.


Just beware, along with the USABLE amperes per dollar, you still have to consider maximum charge and maximum discharge characteristics, as this will effect the maximum cycle rates for maximum use.

Anyway, as stated, this is how I judge lithium batteries.

drivesafe
4th June 2021, 09:59 AM
As posted in the first section, my primary consideration when selecting a lithium battery, for best value, would be to get the highest Amperes per Dollars invested.

But you also need to look at your intended usage and whether a given brand or model can adequately meet your needs or will it actually underperform if used the way you intend it to be used.

The next factor I take into account is the MAXIMUM CONTINUOUS DISCHARGE rating.

Any Lithium Battery with less than a 1C rating over the total capacity of the battery, is not something I would consider buying.

A SPECIAL NOTE, MAXIMUM CONTINUOUS DISCHARGE rating should NOT be “Time Limited”. Quite a few batteries have a “reasonable” Maximum Continuous Discharge rate, but only for a limited amount of time.

If you are buying a lithium battery that is intended to supply high currents for specific purposes, you want a battery that will supply that high current for the entire capacity of the battery.

In other words, if a 100Ah Lithium Battery is rated at a maximum “CONTINUOUS” discharge current rate of 100 amps, that should be for 1 hour, at which point, the BMS shuts the battery down when it has supplied its 100 amperes of capacity at a discharge current rate of 100 amps.

I find it somewhat strange that a battery will be rated at a MAXIMUM CONTINUOUS DISCHARGE rating, but only for say 30 minutes, or what ever. This is not the maximum “CONTINUOUS” discharge rate, it is the highest current discharge rate for a given limited time, so is not a genuine maximum “CONTINUOUS” discharge rating.

Some of the lithium batteries I tested, were tested with a discharge current of 400% of their rated capacity till they were flat ( BMS shut down ).

So unless a battery has its genuine MAXIMUM CONTINUOUS DISCHARGE rating specified, the real rating of the battery is at best, speculative. And this means you really do not know what the SAFE MAXIMUM CONTINUOUS DISCHARGE rating is.


If you are planning to do no more than boil a jug or run a juicer for a few minutes, all is fine with some sort of time limitation, but if you are planning on doing some serous cooking or want to run air conditioning or a heater, this time limited maximum, in my opinion, is just not good enough.

Blknight.aus
4th June 2021, 10:48 AM
to throw in on top of this dont forget to factor in the BMS features.

the best lithium in the world wont hold up in a bank if the BMS is a chunk.

drivesafe
4th June 2021, 12:14 PM
In every case of a lithium battery fault that I have come across ( other than the two I deliberately damaged ) the problem was always a faulty BMS.

drivesafe
6th July 2021, 06:54 PM
Hi folks, I am having conversations with customers on a weekly basis about whether to stay with Lead Acid batteries or covert to Lithium batteries.

The basis of this thread is to go over the Pros and Cons of both a Lead Acid battery plus Traxide system, verses a Lithium Battery plus DC/DC setup.

As I have stated in other threads, if I was buying a new camper trailer or caravan, I would be fitting Lithium House batteries. This thread is specifically about setting up a vehicle, and the info applies to most makes of modern vehicles, not just Land Rovers.

The biggest single problem with buying a lithium battery, is finding a good brand. There are a number of cheap lithium batteries now, but most are, to put it simply, pure rubbish.

There is one specific brand, mentioned here on AULRO, that is of such poor quality that they are failing to last more than 2 years, and this is in situations where the batteries have not had much use.

As I have mentioned in other threads, getting a so called “Well known brands” does not mean have a quality product. So it’s buyer beware!

If you get a good quality lithium battery, you should expect to get at least 10 years of constant use, and at least 15 years of intermittent use, which is what most on this forum should expect.


So lithium battery lifespan should be excellent.


Lead acid batteries should give you at least 4 years of good use. So 2 to 3 lead acid batteries will be needed to get the equivalent lifespan.

You need to compare the up-front cost of a lithium battery to that of cost, spread out over many years, of replacing lead acid batteries. It is not that great a difference. Except with lead acid batteries, again, the cost is spread over many years.

Weight Saving. This is no where near as big an advantage as it looks. First off, you need a lithium battery at least 50% bigger than the lead acid auxiliary battery it is going to replace.

Remember, with a Traxide setup, you are able to draw up to 50% of the cranking battery’s capacity to assist in powering your accessories while camping.

With a lithium + DC/DC setup, the cranking battery is not available. So with a D3, you will need at least a 120Ah lithium battery and with the new Traxide D4 kits, you would need at least a 150Ah lithium battery to give you the same amount of usable battery capacity.

This not only means your weight saving is a lot less, it also means a lot more Cargo space is lost.

You can buy Slimline Lithium Batteries that can be mounted in out-of-the-way places, but this is usually at an even higher cost.


The biggest drawback with going to Lithium batteries, is the recharging time. NOTE, this same drawback also applies when recharging Lead Acid batteries with a DC/DC device.

When deciding on the size of the DC/DC device, you first have to make sure of the maximum safe charge current your Lithium battery can tolerate the size of DC/DC charger you want to use.

For instance, a 30 amp DC/DC charger for a 120Ah Lithium battery and a 40 amp DC/DC charger a 150Ah Lithium battery

In both cases, from low to around a 95% state of charge is going to take at least a 4 hour drive, and much longer when your SMART alternator runs a low voltages.


SPECIAL NOTE, if you are running a fridge off the lithium battery while you are charging it, the recharge time blows out even further.

It’s amazing how none of this relevant info is ever explained in all the glossy advertising they use to sell DC/DC device.


Because a Traxide setup causes the BMS to run the alternator at a higher voltage for a longer time, and because of the huge alternators in D3s and D4s, you can replace the same amount of energy, that a DC/DC setup takes 4 hours to do, but achieve it in around 1 hour of driving.

This 1 hour drive will charge the cranking battery from around 50% SoC to 95% and charge the auxiliary battery from 10% SoC to around 95%.

Thats around 110Ah to 120Ah replaced in the first hour of your drive. There is no other dual battery system available, that can replace this amount of used battery capacity in such a short time.

In addition to the much faster recharging, while driving around town between trips, every time you start your motor, a Traxide system allows the auxiliary battery to assist the cranking battery when you start your motor. This is not available with a DC/DC system.

After short drives, the auxiliary battery is usually at a higher state of charge, so that when you turn your motor off, the auxiliary battery slowly back discharges into the cranking battery. This keeps the cranking battery both in a higher state of charge and in a far better maintained state.


These two functions mean that your cranking battery will recharge quicker, which is a major advantage if you are doing a lot of short drives.

The ability of keeping your cranking battery in a higher state of charge and better condition, ultimately gives your cranking battery a longer lifespan. This then reduces your long term battery replacement costs.

This type of battery life improvement is just not available with a DC/DC setup.


You will often read how someone, who has lithium batteries, finds there solar charges them better than it ever charged their lead acid battery. I have not covered anything to do with solar charging because in the real world, there is actually very little difference between the way the two battery types charge when solar is used.


In the vast majority of setups, solar charging will charge lithium batteries no quicker than it will charge lead acid batteries.

If you are in the process of trying to see which system is going to be the best for your needs, do your homework.


There is a lot of exaggeration about what lithium batteries can do and just as much deliberate misinformation about the so called drawbacks of lead acid batteries.

In most cases, a Traxide system offers far more advantages than a lithium setup and for a fraction of the cost.