I am doing some research on upgrading to Lifepo4 batteries for my camper to replace a set of 105AH AGM group 31 batteries (210AH total). I would like to be around double that when I am done (~400AH). So I was considering buying individual cells and making a 4s2p battery, but looking at the cost of 8 x 200AH cells, plus the cost of 150-200A 4s BMS, it looks more cost effective to buy two ready to use 200AH 12.8v Lifepo4 batteries. Just curious if anyone else was doing some comparison shopping out there and what route you had decided to go in?
Lifepo4 battery buying options - Alibaba
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Bob B
Emperor Of Solar
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I used individual 190 AH cells in a 2P4S configuration .... but things have moved forward a lot since then. If I were going to do it right now, I would probably go with matched and batched 280's.
The ready made batteries are very tempting .... and I did buy a 100AH with smart BMS ready made for my boat electronics and am happy with it .... but there are a lot of vendors pushing sub standard product in the ready made, so do your homework and find someone getting good reviews on this forum.
Don't trust the reviews you might find on Amazon.
Even on this forum I am sometimes skeptical of new members who give a thumbs up to a product.
The ready made batteries are very tempting .... and I did buy a 100AH with smart BMS ready made for my boat electronics and am happy with it .... but there are a lot of vendors pushing sub standard product in the ready made, so do your homework and find someone getting good reviews on this forum.
Don't trust the reviews you might find on Amazon.
Even on this forum I am sometimes skeptical of new members who give a thumbs up to a product.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
As Solar Geezer and longtime member here I'll chime in a tad.
Battleborn 12V/100AH is $900 USD. Great Batteries & Good Company that "do it right".
Current the 280AH cells are the most popular as they are the Best Bang per Buck "today".
- Matched & Batched EVE-280's are 125.00 US ea. 4 ee required to make a 12V pack, $500.
- That provides 12V from 10.000V (0% SOC to 14.0V 100% SOC) All of the juice lives between 12.0 to 13.6V, LFP is very tight and has a flat voltage curve. This provides 3,584Wh or 3.58kWh.
- a 12V/280AH pack can output up to 280A for 1 hour (1.0 C-Rate) and can be charged with a Max of 140A for 2 hours (0.5 C-Rate)
4X 280AH Matched cells: $500
1X BMS capable of 250A Discharge and 125A charge, $200 and up pending on extras, features & functions of course.
OR lower Amp capable mosFET based BMS such as a 4S JBD 125-150 ish,.
1X MRBF 250A Fuse with bracket $25
- going higher end: 500+250+25 = $775 USD for 280AH.
+ Casing or frame as you desire, many options from DIY with plywood or ABS casings to whatever you can imagine as long as the interior is NON-Conductive !
There are MANY prebuilt batteries but NOT that many that are fully trustable. Will has reviewed many and boy... some were a real eye opener but others really stood out for being good quality. The big Commercial companies like Battleborn, SimpliPhi, Relion are Premium quality & priced accordingly.
If you download this pdf it will tell you most everything you need to know about assembling your own LFP Pack.
diysolarforum.com
Hope it helps, Good Luck.
Battleborn 12V/100AH is $900 USD. Great Batteries & Good Company that "do it right".
Current the 280AH cells are the most popular as they are the Best Bang per Buck "today".
- Matched & Batched EVE-280's are 125.00 US ea. 4 ee required to make a 12V pack, $500.
- That provides 12V from 10.000V (0% SOC to 14.0V 100% SOC) All of the juice lives between 12.0 to 13.6V, LFP is very tight and has a flat voltage curve. This provides 3,584Wh or 3.58kWh.
- a 12V/280AH pack can output up to 280A for 1 hour (1.0 C-Rate) and can be charged with a Max of 140A for 2 hours (0.5 C-Rate)
4X 280AH Matched cells: $500
1X BMS capable of 250A Discharge and 125A charge, $200 and up pending on extras, features & functions of course.
OR lower Amp capable mosFET based BMS such as a 4S JBD 125-150 ish,.
1X MRBF 250A Fuse with bracket $25
- going higher end: 500+250+25 = $775 USD for 280AH.
+ Casing or frame as you desire, many options from DIY with plywood or ABS casings to whatever you can imagine as long as the interior is NON-Conductive !
There are MANY prebuilt batteries but NOT that many that are fully trustable. Will has reviewed many and boy... some were a real eye opener but others really stood out for being good quality. The big Commercial companies like Battleborn, SimpliPhi, Relion are Premium quality & priced accordingly.
If you download this pdf it will tell you most everything you need to know about assembling your own LFP Pack.
Luyuan Tech Basic Lifepo4 Guide
This document was posted to the forum by Amy from Shenzhen Luyuan and written by Steve S. It was meant to be posted as a resource. Below is her description of the resource: Dear all friends in the forum, This file in the attachment was...
diysolarforum.com
Hope it helps, Good Luck.
Hmmm... I noticed that I can order 4 x 3.2v Lifepo4 420AH prismatic cells for $568 (free shipping) on their site, and I would only need to add a BMS ($150'ish). So for about $725, I could have a 420AH 12.8v Lifepo4 battery. Sounds like a good return on my investment. But I get what you are saying by, "Premium quality & priced accordingly." Usually, you get what you pay for. I just wonder if you pay more than double for a similar sized battery system, are you actually getting more than double the value? Or if you look at it from the other perspective, do the cheaper cells last only 1/2 as long as the more expensive batteries? Maybe it's better to DIY, then you know exactly how the battery is built and which BMS is protecting the cells.
There are a couple threads on the 420 with big red flags waving.
Also, just doing some simple math with the cost of 4 x 3.2v 280AH cells, around $460. Plus the cost of a 150A 4S BMS ($120), and another $50 for a case to stuff it all in. Now we are around $630. If that's the DIY cost for a 12.8v 280AH battery, that makes me very skeptical that they can sell an assembled Lifepo4 12.8v 300AH battery for $410. Something is just not adding up.
Not to mention most ready to use BMS only 100a
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Again LFP is LFP the chemistry is a long established & refined. There are a few slight variants for specialized uses like Cold Weather cells with Yttrium. Bottom Line, is AMP Hour capacity is relative to cell size (Physical Volume) and the quantity of material within.
An EVE-280AH cell weighs 5.2 Kg (11 Pounds)
A 140AH cell will weigh in at approximately 2.6kg
A 420AH cell should come in close to 7.8kg +/-
LFP does not have different Energy Density chemistries, LFP is LFP and Battery Cell weight: close to 5.1kg is not 420AH, not possible unless someone reinvented a new LFP Chemistry with higher density, that noone knows about.
An EVE-280AH cell weighs 5.2 Kg (11 Pounds)
A 140AH cell will weigh in at approximately 2.6kg
A 420AH cell should come in close to 7.8kg +/-
LFP does not have different Energy Density chemistries, LFP is LFP and Battery Cell weight: close to 5.1kg is not 420AH, not possible unless someone reinvented a new LFP Chemistry with higher density, that noone knows about.
I am sure we would know.
Yep... I would be very skeptical if a 420AH cell weighs the same as a 280AH. Then you know it's just marketing and you are actually paying more for a rebranded 280AH cell. I have noticed that the CALB (plastic shell) cells do have higher densities, and they seem to be proportional to the size and weight, along with the price.
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