LFP battery choice

[Scott'n'Wendy]

Last component I'm researching is the battery itself. There's a ton of different battery brands out there at a ton of different price points from about $400 to $1500.
The names are all peculiar. Like Dakota lithium...but..factories are not in the Dakotas? Battleborn....I dunno, should be a name for body armour. Then there's SOK?
Anyway, I digress.
How do I determine what batteries are well made? Specs are pretty much identical as far charge and discharge rates. Small variations in weights. Nobody seems to give you the specifics of the BMS. I suspect there are only a couple different BMS boards out there. I've read different articles that claim prismatic cells are best for vibration. Others claim cylindrical is best. Everybody says cylindrical cells are the cheapest. However BB are cylindrical type but are among the most expensive out there. SOK is a bit cheaper than BB and has a removable top so you can replace a cell-must be prismatic. Ampere-Time is the cheapest I've seen so far and has pretty much the same specs as all the rest.

So how do I tell if a LFP battery is a quality unit or junk?

[howson]

Last component I'm researching is the battery itself. There's a ton of different battery brands out there at a ton of different price points from about $400 to $1500.
The names are all peculiar. Like Dakota lithium...but..factories are not in the Dakotas? Battleborn....I dunno, should be a name for body armour. Then there's SOK?
Anyway, I digress.
How do I determine what batteries are well made? Specs are pretty much identical as far charge and discharge rates. Small variations in weights. Nobody seems to give you the specifics of the BMS. I suspect there are only a couple different BMS boards out there. I've read different articles that claim prismatic cells are best for vibration. Others claim cylindrical is best. Everybody says cylindrical cells are the cheapest. However BB are cylindrical type but are among the most expensive out there. SOK is a bit cheaper than BB and has a removable top so you can replace a cell-must be prismatic. Ampere-Time is the cheapest I've seen so far and has pretty much the same specs as all the rest.

So how do I tell if a LFP battery is a quality unit or junk?

Look at Will Prowse's YouTube channel and search his videos. He tears down batteries and shows their internals. (Battle Born was initially mad when Will did this with their battery.) It's been awhile since I watched Will's latest stuff, but what he found in some of the batteries is why Battle Born was the only brand he recommended for a time period. (That probably has changed by now--battery industry is constantly changing.)

Howard

[Paul & Deb]

Look at Will Prowse's YouTube channel and search his videos. He tears down batteries and shows their internals. (Battle Born was initially mad when Will did this with their battery.) It's been awhile since I watched Will's latest stuff, but what he found in some of the batteries is why Battle Born was the only brand he recommended for a time period. (That probably has changed by now--battery industry is constantly changing.)

Howard

Will's review is what helped me decide to switch from Lion to SOK on this trailer. I doubled my amp hours but not my cost. I never considered the Battle Borns personally. Even during their seconds sales they're overpriced in my personal opinion.

[Scott'n'Wendy]

Paul & Deb l
The SOK guys say their top is removable for cell replacement. Did you look in there?
howson
I saw a youtube vid, not sure if it was Prowse, but it was a bit dated. I will search for prowse this evening.

I wonder about cell suppliers. I believe they are all manufactured in China.
Is there some key specification that gives you some insight as to the quality of the guts?

[Paul & Deb]

Paul & Deb l
The SOK guys say their top is removable for cell replacement. Did you look in there?

I didn't try to remove the top, but it looks like it would easily come off.

In this picture you can see the screw heads around the "cover" and on the posts.

[howson]

Is there some key specification that gives you some insight as to the quality of the guts?

If there is I do not know it. When I was in the market the majority of GD owners that had upgraded were buying Battle Born. Back then there wasn't a lot of (quality) competition.

[Scott'n'Wendy]

howson Thanks for the Prowse suggestion. Interesting videos. You can certainly tell the difference in build quality between the reasonably priced and the cheapest priced with the teardowns. SOK and Renogy seem to be built far strionger/solid than the cheapest and Will commented he would buy the Renogy over the BB all things considered.

I liked the video where a cheap $15 pwm no name controller kept right up with a $175 Victron MPPT. Guess most of the money goes into pretty packaging. Which gets back to my original query about trying to determine quality. Apparently it's not easy.

[Guest]

For those that follow Will, he has also tore down the much cheaper Ampertime and Chin batteries from Amazon and he likes them. They are around $300 each last time I looked and Amazon offers and extended warranty on them. Personally when I made the choice on brand, I looked to price, the warranty, and if the vendor is based in the US in case a warranty claim should be made. I purchased an AIMs battery where they provided detail information on the cells used and their specifications which is rare. They use a high quality BMS and each of their cells has a diagnostic board with a thermal fuse similar to a Tesla design. They also have a ten year warranty and their latest versions have built in battery monitoring with blue tooth. Older versions did not have a low temp cut off where that's of no concern to me since my battery will never be operated at or below freezing and is conditioned in the pass through for a heating and cooling benefit. Its also closely monitored.
Battle Born batteries are good quality but they are the most expensive since they are assembled in the US from import components. A completely imported battery will be cheaper and many are just as good. Battle Borns connections are the best IMO.
I've also seen the Dakota brand where they claim an 11 year warranty but I have no experience with them.

Time will tell how good these batteries really are and how warranty claims will be handled where I expect most after several years will be deemed as normal end of life by the makers. They are only good for so many cycles and can be consumed in far less than 10 years if used full time and cycled fully.
.
Jim

[AZMike]

I am quite surprised that no one is mentioning Sun Fun Kits (https://www.sunfunkits.com/). I bought their SFK-260 complete battery a few months ago and am completely satisfied with it.

[KSC_Travels]

Scott'n'Wendy My experience with the Renogy is positive. I went with the Renogy 100Ah Smart LiFePO4. Don't know if better or worse than others but worked just fine last season. There are a couple of cool/interesting features with the Renogy though that I don't think others have - might be of interest for you.

This battery has two ethernet-type ports on it. Couple of features this enables.
1. It comes with a switch - which is really just a button on a short ethernet-type cable. When connected to one of the ports, you can put the battery into "shelf mode" for long term storage. Seems to work well. Could be a gimmick, but I used last year and this year and the battery does had no noticeable discharge.
2. You can network two (or more) batteries together so they "talk" to each other. Not sure exactly what this does, but seems like a good thing - allowing the individual BMS to talk to each other.
3. It is now compatible with one of their bluetooth dongles which then integrates into the Renogy app showing battery monitoring info
4. Renogy now sells a relatively cheap ($50 CAD) monitoring screen as well if you don't want bluetooth. Plugs into one of the ports and reportedly gives "a more accurate" state of charge than using a shunt as it interfaces directly with the BMS.

The 2nd through 4th features were't a thing when I purchased last year (and I only have one battery) so I haven't used these features - but they seem cool . I am considering adding the BT dongle just because. I use the Renogy app with the solar charge controller so why not?

At the time I purchased the Victron shunt to monitor SOC, but if I were starting now, I might have skipped the shunt and gone with either the bluetooth or monitor screen option instead.

Not trying to advocate one over another... just passing along info!

Cheers!

[Guest]

I am quite surprised that no one is mentioning Sun Fun Kits (https://www.sunfunkits.com/). I bought their SFK-260 complete battery a few months ago and am completely satisfied with it.

Being satisfied with the product is all that matters. Has it performed as expected and for a reasonable period of time for a reasonable price point. However, I'm a little sensitive with makers hanging the flag on their product and making the claim "Made in the USA" when they are Assembled mostly from Chinese components as listed in the description. Misleading.

https://www.sunfunkits.com/productgr...sphate-battery

Jim

[Scott'n'Wendy]

However, I'm a little sensitive with makers hanging the flag on their product and making the claim "Made in the USA" when they are Assembled mostly from Chinese components as listed in the description. Misleading.

Jim

To be fair, this is the case for BattleBorn and AFAIK, all others as well. Import the Chinese components and then wire it, bolt it together here.
The cheaper ones are just assembled in Asia. Cheaper labour...cheaper price.

KSC_TravelsAZMike

I find the interest that most people have in monitoring their charge and/or discharge currents throughout the day kind of odd really. As far as I'm concerned, I will set it up, configure, verify function...then forget all about it. Until something fails. To each their own I guess. Thanks, I will check them out. On edit, whoops...I guess I was supposed to tag AZMike..lol about the SFK..

[Paul & Deb]

I find the interest that most people have in monitoring their charge and/or discharge currents throughout the day kind of odd really. As far as I'm concerned, I will set it up, configure, verify function...then forget all about it. Until something fails. To each their own I guess.

Man do I wish I could do that. I walk by my trailer in the yard multiple times a day and I check my batteries and solar on my phone at least once a day! Imagine what I do when I'm actually out camping! It's an addiction, really.

[KSC_Travels]

I find the interest that most people have in monitoring their charge and/or discharge currents throughout the day kind of odd really. As far as I'm concerned, I will set it up, configure, verify function...then forget all about it. Until something fails. To each their own I guess.

Copy that... The argument for monitoring, for me, was that with LiFePO4 it's difficult to tell SOC by voltage alone due to flat discharge curve. You could be 80% discharged and not know it if looking only at voltage. The same also renders the battery lights on the control centre all but useless.

Cheers!

[Guest]

There is no need to sit and look at the battery condition, charging or discharging but rather to set triggers to alert a person of an impending issue. Other methods can be used along with a battery protect feature. The BMS can be used as the redundant system or for some the primary safety.

The Victron BMV-712 or Smart Shunt is a valuable device to monitor the battery(s).

Jim