AGM and golf carts vs. Lithium Battery Test

Here's a link to the video:
https://www.youtube.com/watch?v=iy3hga_P5YY

Very informative.

Are you sure you have accurately computed your amp hour use?

MIGO TMI..heh. He packs so much tech data in so fast it's impossible to evaluate. And I am a tech tho not of the electrical variety. One thing I fished out of the flood was that the cheap 6V golf cart batteries were the most cost efficient. Strange that he didn't include Trojans or another high quality brand into the test. He then launches into the life cycle cost analysis. That's where I gave up. I have to admit that I have suspicions that this fellow is in the pocket of Battleborn. The info about 6V batteries was inserted in a very fleeting manner, almost as if he was hiding it.
As for life cycle I will admit that if you keep your RV for 20 years or so then yes, Lithiums may pay for themselves. But most of us will not. And even if you have to replace your 6V battery pack once or twice over your time in the RV the costs will never approach the $4000 LiB battery pack price.
I have never been a fan of AGM, they are designed to start a vehicle not store energy. Golf cart batteries are designed to store power and so are the LiB.
So I'll stick with 6V unless the price of LiB plummets. Something I doubt will happen because of the scarcity of lithium.

A simpler comparison between AGM & lithium at different loads & temperatures performed by Battleborn. Of course Battleborn did the testing, but similar results.

Battleborn You Tube AGM to lithium test

vermilye wrote:
A simpler comparison between AGM & lithium at different loads & temperatures performed by Battleborn. Of course Battleborn did the testing, but similar results.

Battleborn You Tube AGM to lithium test

But you see, they excluded golf cart batteries which seem to be the winner when cost/watt-hr is computed. Remember what Disraelli may have said: "There are three types of lies, lies, damned lies and statistics." And they seem to be lying by exclusion.

agesilaus wrote:
One thing I fished out of the flood was that the cheap 6V golf cart batteries were the most cost efficient.

I caught that also, but they did not do well under high discharges.

agesilaus wrote:
Strange that he didn't include Trojans or another high quality brand into the test.

I would love to see a test like that, but my gut says it will be another "life cycle" issue. I suspect the Trojan's will handle more charge/discharge cycles. Difficult to prove outside of a fully automated professional laboratory envirnment.

agesilaus wrote:
So I'll stick with 6V unless the price of LiB plummets.

It has ! First, most (all?) large LiFePO4 cells are made in China. Battle Born and other companies buy individual cells connect them together install a battery monitoring system and put them in a nice sealed box.

Not only can you buy very similar 100Ah individual cells directly from China, but they are also sell 200Ah and 280Ah cells ! The total price of a 280Ah 12V battery pack is actually LESS than 1 Battle Born 100Ah 12V battery.


$433 280Ah LiFePO4 Cells Tested: Cheaper than lead acid! This does NOT include the BMS and some other small consumables.

If you want to see more videos like this, go to YouTube and search for "280ah lifepo4".

These 'value comparisons' based on the cost of the battery/the number of cycle are kind of silly. First, I sincerely doubt that the manufacturers have actually done any where near the testing necessary to know what the cycle life of their cells are when those cycle lives are > 2-3000. They model it, and while these models could be accurate, they have a lot of parameters that need to be assumed.

Secondly, and most importantly, so called 'cycle aging' is only one of the ways that a battery ages. There is also something called 'calendar aging' which is the rate at which a battery ages as a function of time, regardless of whether it is being used or not. This is a factor for both lead-acid and lithium batteries. It is not so important for lead acid batteries as they typically degrade from cycle aging before calendar aging becomes an issue. However if you are going to advertise a battery with a 10,000 cycle life, then calendar aging is absolutely an issues. This had been researched for LiFePO4, and the rate of aging is a function of temperature (mostly) and storage state of charge (less so). For a 100% charged LiFePO4 battery stored at 30C the calendar aging is around 4% per year. If you take providing 80% of rated capacity as the metric for battery failure, then even an LiFePO4 battery will only 'last' 5-6 years, regardless of the number of cycles.

Assuming you are cycling your battery hard every day (365 cycles) then there is really not much advantage to a battery that provides more than 2-3000 cycles, as calendar aging will kill it long before cycle aging. For most of us here that may only deeply cycle our batteries 50 - 100 times a year, then 1000 - 2000 cycle is plenty.

Now there are plenty of other reasons to like lithium batteries, such as lower weight and volume, flat voltage curve, simple charging profile etc. But just dividing the price by the cycle life is not an honest or accurate metric.

PS For anyone who wants to learn more about this, here are some papers and a thesis on 'calendar aging':
U. Waterloo Thesis
Journal of Energy Storage
DuBarry et al., 2018

Fair warning, these are highly technical and make the prior video look a bit simplistic.

I scrolled to the test section a little before the 8min mark. He doesnt mention cycling the flooded deep cells before performing the test. Trojan specifically says the batteries will not reach max capacity until 50-100 cycles. He didnt test trojans but im guessing all flooded lead acid would perform similar regarding capacity and cycles. 

Appears to be a battleborn commercial from the little i watched. Notice how its edited so that when the voice is saying "so what is the best battery???" the battleborn label is right there main screen and the other batteries are blank. To me thats subliminal stuff they pull in commercials.

They went through a lot of trouble to control temps and stuff but in my opinion purposely did not cycle the flooded battery.

FWC wrote:
Assuming you are cycling your battery hard every day (365 cycles) then there is really not much advantage to a battery that provides more than 2-3000 cycles, as calendar aging will kill it long before cycle aging. For most of us here that may only deeply cycle our batteries 50 - 100 times a year, then 1000 - 2000 cycle is plenty.

Exactly my point. If your battery makes it for 6 years and you cycle them 100 times a year that's only 600 cycles. The potential to get 5000 or 10000 cycles is meaningless in RV terms.