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shagginwagon83 
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Joined: February 07, 2016
Posts: 4314
Location: SWVA
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 Posted: Mon Jul 07, 2025 7:24 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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@vwhammer what BMS are you using? I bet its at least 200a because of the fan. On my next pack I am interested in upgrading from the JBD BMS.
It is strange to me that the Victron BMS would allow such current into the batteries.
On compression, I mostly agree with you that is not needed - however, for mobile applications, I feel compression is important to isolate movement between the cells. Most importantly, the studs. A user here T3Tris replaced his solid bus bars with flexible ones. I would say if you had those flexible bus bars then I agree compression is not needed.
I have been loving my DIY packs, however you can get prebuilt 280aH packs for $372 shipped. Yeah probably not EVE quality cells but you do get convenience of an enclosure and some warranty.
I noticed there are even larger capacity EVE cells now - something like 600ah cells for around $115 each - crazy to think I could build a 1200aH pack for under a grand. Off grid AC project will be sooner than later!
One last thing. I feel 5 years from now we are going to have battery tech like solid state batteries that will blow LiFePo4 away. I can't wait, as it will really unlock more off grid camping for our family.
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"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
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dhaavers
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Joined: March 19, 2010
Posts: 8371
Location: NE MN (tinyurl.com/dhaaverslocation)
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| Posted: Mon Jul 07, 2025 7:42 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| shagginwagon83 wrote: |
…you can get prebuilt 280aH packs for $372 shipped. Yeah probably not EVE quality cells
but you do get convenience of an enclosure and some warranty... |
Related: I recently came across this…300ah EVE Grade “A+” cells with 200a BMS & Bluetooth…$350, (very recently $320 on sale).
https://www.amazon.com/gp/product/B0DSV5Y9HH/ref=ox_sc_act_title_1?smid=A14716HZ3FBVER&th=1
I’m sticking with my AGM’s for the time being, but I (with DanHoug’s blessing) recommended this to my sister for her new teardrop trailer. She’ll probably never need solar! Hasn’t arrived yet but it’ll go in soon & I’ll try to get some inside scoop to share.
- Dave
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86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS> |
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shagginwagon83
Samba Member
Joined: February 07, 2016
Posts: 4314
Location: SWVA
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| Posted: Mon Jul 07, 2025 7:55 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| dhaavers wrote: |
| shagginwagon83 wrote: |
…you can get prebuilt 280aH packs for $372 shipped. Yeah probably not EVE quality cells
but you do get convenience of an enclosure and some warranty... |
Related: I recently came across this…300ah EVE Grade “A+” cells with 200a BMS & Bluetooth…$350, (very recently $320 on sale).
https://www.amazon.com/gp/product/B0DSV5Y9HH/ref=ox_sc_act_title_1?smid=A14716HZ3FBVER&th=1
I’m sticking with my AGM’s for the time being, but I (with DanHoug’s blessing) recommended this to my sister for her new teardrop trailer. She’ll probably never need solar! Hasn’t arrived yet but it’ll go in soon & I’ll try to get some inside scoop to share.
- Dave |
It is very popular to false advertise when it comes to the quality of cells.
And on Amazon, fake reviews are even more popular. I ran a Fakespot report that analyzes the review quality - its soon to be a discontinued service, but it still works for some reason.
https://www.fakespot.com/product/12v-300ah-lifepo4...rid-system
Fakespot might be wrong, but it indicates "only 20.6% of the reviews are reliable."
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"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram: @joannthevan |
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shagginwagon83
Samba Member
Joined: February 07, 2016
Posts: 4314
Location: SWVA
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| Posted: Mon Jul 07, 2025 7:59 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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https://www.youtube.com/watch?v=FA59VNwSqjc
This video shows it LOOKS to be nicely built! Fake reviews might have been added to jump start their listing.
A couple of mentions of BMS issues on the diysolarforum forum, but that can always get upgraded/swapped out.
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"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
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dhaavers
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Joined: March 19, 2010
Posts: 8371
Location: NE MN (tinyurl.com/dhaaverslocation)
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| Posted: Mon Jul 07, 2025 8:29 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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Granted, you gotta do your own homework. What does fakespot say about your eBay battery? Just curious.
- Dave
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86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS> |
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shagginwagon83
Samba Member
Joined: February 07, 2016
Posts: 4314
Location: SWVA
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| Posted: Mon Jul 07, 2025 8:45 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| dhaavers wrote: |
Granted, you gotta do your own homework. What does fakespot say about your eBay battery? Just curious.
- Dave |
It has an A rating - https://www.fakespot.com/product/eco-worthy-12v-28...ups-marine
I also like using the "how many sold" Amazon analytics. I feel the more that is sold, the better - more likely to be around for awhile.
Also, for what it's worth, I have a Eco Worthy 50aH pack on my bench right now - it capacity tested great. I have friend who bought 48v 100aH server racks by this brand and he liked the quality.
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"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
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dhaavers
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Joined: March 19, 2010
Posts: 8371
Location: NE MN (tinyurl.com/dhaaverslocation)
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| Posted: Mon Jul 07, 2025 9:17 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| shagginwagon83 wrote: |
| I also like using the "how many sold" Amazon analytics. I feel the more that is sold, the better - more likely to be around for awhile... |
Likewise. Thanks for the follow up.
- Dave
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"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS> |
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vwhammer
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Joined: May 20, 2006
Posts: 1010
Location: Boulder CO.
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| Posted: Tue Jul 08, 2025 12:17 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| shagginwagon83 wrote: |
@vwhammer what BMS are you using? I bet its at least 200a because of the fan. On my next pack I am interested in upgrading from the JBD BMS.
It is strange to me that the Victron BMS would allow such current into the batteries.
On compression, I mostly agree with you that is not needed - however, for mobile applications, I feel compression is important to isolate movement between the cells. Most importantly, the studs. A user here T3Tris replaced his solid bus bars with flexible ones. I would say if you had those flexible bus bars then I agree compression is not needed.
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Indeed it is a 200 amp Daly 100 balance BMS.
Supposedly it has some cell balancing functions but with testing by several people it maybe does not work like it should.
Either way it seems to function for what I need and I have had no issues with imbalance between cells.
I should also point out the size difference between this BMS and a 200 amp BMS from the same company from 2 or 3 years ago.
The big one also requires a dongle to be plugged in so you can have bluetooth connectivity.
I bought a bunch of components that are supposed to work with the BMS like a heater control module and a simple on off switch but have not been able to make those work with the phone app.
You can buy a USB to RS485 cable so I can use a laptop to tinker with it more but I found a few work arounds and was kind of in a hurry so I bailed on messing with all that.
It would be pretty dope if I could sort out all the extra bits that are available for these BMS units as it would let you set it up to comunicate with nearly any thing.
There are some CAN BUS bits that technically could let you use this system with something like the Garmin RV control systems or many of the other CAN BUS controls that are on the maket.
I've searched for vids and documentation to aid with component set up and the like but most are from Daly themselves and are very vague.
On anoter note you make a good point on the compression to deal with vibration.
I am a fan of flexible bars between cells (even though they are not implemented on my DIY battery I posted).
I have found, with appropriate abrasion resitant material between cells (look up fish paper) and some simple taping to keep pack movement to a minimum, that I have had no real issues with packs used in vehicular applications. |
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shagginwagon83
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Joined: February 07, 2016
Posts: 4314
Location: SWVA
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| Posted: Fri Jul 11, 2025 6:38 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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That is a huge difference in BMS! I personally don't have a 200a need but I could understand others needing so.
Thanks for the info.
Also, we've officially hit less than $1 per aH. You can get a 100aH for $95.88. It is wild to me that BattleBorn has their 100aH for $675 still. Internally, they are built better - very suitable for marine applications, but for these vans a little overkill.
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"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
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vwhammer
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Joined: May 20, 2006
Posts: 1010
Location: Boulder CO.
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| Posted: Sat Jul 12, 2025 1:17 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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I only chose a 200 amp BMS because I want this pack to run an 1800 watt induction burner.
Induction would be getting close to 150amps on its own.
I want to have a little more wiggle room to run lights, fans and/or my fridge with the induction going at the same time.
Really only chose 360AH for this battery so I am not pushing the battery too much with the induction running.
I have right at about $500 in this pack complete with BMS and will be printing an eclosure for it as soon as my 3D printer shows up.
After the enclosure is made it should be good for any environment I design the encloser for.
With the need for air cooling it obviously will not be water tight but most batteries on the market right now are not water tight.
For my use I don't really have a need for it to be water tight
I personally am a fan of more capacity than you might think you need.
I don't ever want to think about what I am trying to run (within reason)
This unit will be going in my 5th gen 4runner.
I have 350 watts of alternator charging and 320 watts of solar charging should I need it to get the battery topped off.
I would probably have to be parked in one spot without sun for a few days before I need to be concerned about a low battery with the few things I need power for.
I could run my induction cooker for more than 2.5 hours at full power on this particular battery.
I suspect I would not be running it for more than 20 minutes at a time and thats assuming I can not cook on a fire (which is totally possible in Colorado)
Anyway I could blab on about my specs and reasoning forever but yeah I think this battery will work and I will likely build more batteries for other things.
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Pretty normal daily driver build
https://www.thesamba.com/vw/forum/viewtopic.php?t=708418&highlight=
4x4 build
https://www.expeditionportal.com/forum/threads/volkswagen-vanagon-4x4-conversion.162055/ |
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blackglasspirate
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Joined: June 24, 2006
Posts: 1632
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| Posted: Sun Jul 13, 2025 10:29 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| vwhammer wrote: |
While I am not an expert I do work with the lifepo4 chemistry almost every day, both at work and in my own time.
I also do a lot research on the chemistry in order to keep up with any new advancements.
I work with many different brands of premade batteries and have built several batteries of my own.
Here is a quick and dirty 360ah 12v battery with heaters and BMS that will be going into a DIY enclosure after some testing
With that said, I have found LiFePo4 to be very safe even when being abused or possibly set up incorrectly.
In EVs and elecrtic motorcycles people often draw way more current than most manufacturers would ever recomend and they typically take it without issue.
I also have a good example of an issue we had at work on a customer build where for whatever reason we had an auxillary alternator freak out and go into hyper mode and pump 25 volts at nearly 250 amps into a 12v 1320 amp hour Victron battery set up for what was likely over an hour on a short drive for a photo shoot.
Did it wreck some stuff?
Yes. (see pics)
Yes it did but it did not burst into flames nor did it catch any of the wood enclosure around it on fire.
As you can see the batteries obvioulsy got really hot.
These Batteries were basically molten and stuck to the wooden floor of the cabinet they were in.
For the record Victron stuff typically has so many failsafes built into every component that it is actually very hard for anything like this to happen but here we are.
Also for the record we never did actually sort out what caused this failure but every other component in the system still worked fine because all of victrons systems kicked in and shut things down when it should have. (well other than the BMS)
The alternator did not survive so we could only assume that we were given the wrong alternator (24v vs 12v)or the regulator was not programmed correctly.
Anyway I trust the chemistry but there are some precautions that need to be observed.
You need proper charging for LiFePo4 from any source you may be charging from be it solar, alternator or home 120v.
The fun thing is if you do not have proper lifepo4 charging it is usually the charger that fails and not the battery in most cases.
I also recomend proper abrasion resistance on the battery itself and some type of enclosure to protect the thin outter shell of the cells.
The outter shell material is very thin and not really intended to protect but simply to enclose.
A small dent can affect the flow of electrons in a lithium cell and should be avoided.
you also do not want to wear away the plactic coating on the outside so that the metal case is in contact with any other metal.
Given the right environment this can lead to galvanic corossion which could eat through the thin casing in short order and destroy the cell.
Ok moving on to compression.
Short answer, I would not wast my time.
Compression needs to happen during initial testing of the cell to help remove any gas that may be trapped in the porus material inside the cell so electrolite may take the place of that gas.
After that initial testing, compression is not only no longer needed but does not really help with anything.
Yes you will see that some maufacturers say that compressing the cells will increase the cycle count but what is not mentioned is the fact that the cells will likely degrade simply due to time well before any of those extra cycles are ever realized.
For example lets say your cycle count goes from 2500 with no compression to 4000 with compression.
How many times do you suppose you cycle a battery in a camper van?
If I was generous lets say 50 time a year.
Its not hard to do the math to realize that that battery will be long dead and will have been replaced many times over before you ever hit the minimum cycle count.
compression is necessary for the first few cycles while at the manufacturer during testing but virtually pointless after that.
I should also point out that compression no matter how strong is completely usless to combat swelling of cells.
The swelling on these cells happens at an atomic level and there is no press on this planet strong enough to keep it from happening
Ok now I am just rambling.
DIY cells are fine as long as you have all the necessary safety features and ensure proper charging and discharging protection.
Premade batteries are also fine and might save you the hassle of installing and programming a BMS or heaters and offer you a premade enclosure to protect the cells but still aslo require the same charging and discharging equipment to make the battery last as long as possible and to ensure you are not damaging the battery or your alternator. |
This is great info. Thanks for the detailed explanation - that's all very helpful.
I took out my cells to inspect them and "fortify" the whole setup and was planning to put them back in. Then I managed to strip the threads on one of the terminals as soon as I put it back in. So, now it's sitting on the bench until I re-tap/thread it :/
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vwhammer
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shagginwagon83
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Joined: February 07, 2016
Posts: 4314
Location: SWVA
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| Posted: Mon Jul 14, 2025 6:19 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| vwhammer wrote: |
It's kind funny that you posted this when you did because I was just watching a bunch of stuff about lifepo4 and their inherent saftey over other lithium chemistry.
Then, a couple days after I replied here, Will Prowse posted a vid about lifepo4 saftey.
https://www.youtube.com/watch?v=60LEo0Rwpp8 |
I love Will Prowse's videos - thanks for sharing.
I wonder what happened in Alika's case? I know he bypassed the BMS. Now I think about it, I want to say this was not Alika's LiFePo4 pack he assembled, but rather another chemistry.
This makes me feel SOO much better about my DIY packs in the van - thanks for sharing!
Off topic, but what 3D printer did you buy? I bought the Bambu Lab H2D and I love it.
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"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
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