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Forum Index : Solar : [REQ] reco source quality LFP, 15-40Ah
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| john61ct Newbie  Joined: 07/02/2019 Location: United StatesPosts: 27 |
Looking for sources for **quality** LiFePO4 prismatic cells. Ideally 20-25Ah, but 15-40Ah is OK. I'm in North America, but realize a local supplier is unlikely or would be too expensive. Ideally would sell on eBay or at least take PayPal, unless they have a stellar reputation here for integrity & customer service. I'm looking for the bigger block style "prismatics", where one cell is like a brick size, 20-40Ah each, so only need say 6P4S to make a 240Ah 12V pack, worth maybe a grand USD CALB, Winston, GBS, Sinopoly are well-regarded examples. I'd really rather not just ship import myself, if they turn out to test out as sub-par, any warranty doesn't do much good if shipping costs back to China costs more than the cells are worth. If this is an inappropriate place for this request, my apologies, and would appreciate a pointer to a better site. TIA |
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| Boppa Guru  Joined: 08/11/2016 Location: AustraliaPosts: 814 |
Try emailing Winston for local suppliers, I have a exwork colleague living in Columbia and found they have dealers in many cities there, so I would think there are some in the US somewhere- at least they would be in the same country I just emailed them on the contact us email and they replied with a list of every dealer and their location in Columbia which I was able to email to him, one was literally only about 5km from him and he didnt know Apparently their electrical system is 'less than reliable' and he had an inverter fitted, but the person installing it wanted to make up the battery bank with 12v car batteries in series/parallel strings... 4 in series, and 6 strings of them in parallel...  |
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| Solar Mike Guru Joined: 08/02/2015 Location: New ZealandPosts: 1138 |
Google "EV batteries USA" and the list is extensive, eg Voltronix is one example; they seem to have a fair range stocked. I wouldnt trust any batteries purchased on EBay. Cheers Mike |
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| john61ct Newbie Joined: 07/02/2019 Location: United StatesPosts: 27 |
eBay is much better for overseas purchases than Ali, their mandatory NQAMBG is very straightforward, almost instant. Obviously the ideal is a known trusted source. Thanks for the reco so far. |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
for those in the US. The battery hookup has some 26650 lifepo4 cells for sale  the voltages of 4 series cells is well matched to 12 volt. you could fit balance wires to fit a hobby charger or something standalone from knacro or jiller my best estimate is this is 30% cheaper than retail for larger prizmatic cells however the hassle and expense of pack building means it really is only viable for something small. still would be handy for tinkering. I'm confused, no wait... maybe I'm not... |
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| yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
For higher power uses and extreme conditions and reliability it is all about the quality of the BMS. Dont expect the tiny cheap Chinese boards with unknown components to last. there are drop in lead acid 12v replacements with good inbuilt BMS including low temperature cutout, that's a feature I dont use in OZ (but I probably should). there is even some with inbuilt heating. 5-10 yr warranty and some can be series connected and they have good terminals. Relion, battle born, renogy My preference is to use individual prismatic cell blocks and an external BMS. In my opinion the 72 ah CALB metal jacket cells are the best quality cells. However I dont think I have ever seen a decent price for them in the US. I am also in two minds about the value of cells that can last 12-18 years if you are not in it for the long haul, lets face it, things change. It might be better value to sniff around for some pre-owned cells that still have good capacity left. I'm confused, no wait... maybe I'm not... |
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| john61ct Newbie Joined: 07/02/2019 Location: United StatesPosts: 27 |
Well it's great to get responses, but. . . For purposes of this thread: No interest in second-hand, nor in small cylindricals, nor in drop-ins, nor discussion of ancillary electronics to deliver "BMS" functionality (however y'all define that), all those ideas are OT for this thread, OK? Good news is, I am resigned to paying a lot more per Ah than they do in Australia and Europe, fact we get top quality depp cycling lead banks so much cheaper maybe balances out. So, **quality** of the cells, the integrity and stability and customer service attitude of the seller are I think all I care about. So "reasonable" pricing or not, long as it fits my OP request, anyone with sourcing info within North America, please post and I'll ask for quotes and reply what I get. |
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| john61ct Newbie Joined: 07/02/2019 Location: United StatesPosts: 27 |
I suppose getting baseline comparisons from overseas sources is OT as well, but it's my thread so let's allow it, 8-D anyone else feel free to contribute other data points as well, long as it's new top-notch prismatics. Winston Chung calls his "Thundersky" yttrium-doped LiFePO4 / LFP "LiFeYPO4 / LYP" but basically they have the same characteristics, other than (maybe) allowing charging at lower temps. Good cells, but it seems he does not have a rational distributor / reseller business model for the US market and chooses to only entertain individual customers purchasing and importing directly from Shenzhen 8-( Language barriers abound, unless they were being deliberately obtuse. Never heard of zip codes for example (ah, post codes!) I got pricing on qty 32 and 96, ~$46 per cell for 40Ah TSWB-LYP40AHA, delivery cost (via UPS) of ~$800 and $1600 respectively, customs my problem of course. TSWB-LYP100AHA 100Ah actually a bit **more** expensive per Ah at ~$120 each |
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LadyN Guru Joined: 26/01/2019 Location: United StatesPosts: 408 |
Wow John, at those prices for LFP you should go LTO or atleast give it a chance. I know you are very comfortable with LFP but these LTO cells are currently in use in cars and similar harsh environments installed by people way less skilled yourself and they have 0% issues and 100% fun At least a few thousand charge cycles. 10C discharge. Down to zero without cycles dropping. LFP is the LiCo of today. Inertia and familiarity is keeping them alive compared to ability and functionality. $45 including shipping PER CELL. Discounts ofcourse apply for bulk purchases. You are paying way more for way less. I won't pollute this thread with my LTO pitches further I promise :D |
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| john61ct Newbie Joined: 07/02/2019 Location: United StatesPosts: 27 |
>$45 including shipping PER CELL per how many Ah? Have to say skeptical, but not closed minded. Links to learning resources would be appreciated. Preferably solar / "House bank " storage use case oriented, I find those crazy EVers are way too focused on performance over safety & longevity. This project should be adaptable to any chemistry by just changing the setpoints. |
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| LadyN Guru Joined: 26/01/2019 Location: United StatesPosts: 408 |
12pcs 2.3v 40ah LTO battery for $552.00 / lot 12 pieces / lot , US $46 / piece: https://www.aliexpress.com/item/12pcs-2-3v-30ah-35ah-40ah-LTO-battery-2-4v-lithium-titanium-oxide-LTO-battery-for/328401 86313.html Because battery chemistry is in a state of flux right now and it does not make sense to plan on longevity if the chemistry is going to be outdated in 5 years. I am betting that LTO is the LiCo of 2020 |
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| yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Some advice for others reading this I neglected to mention. You will have less problems with fewer cells in parallel. two cells is reasonably trouble free but the chances of high and low resistance cells and connections escalates quickly. this causes some cells to shoulder the bulk of the load in a parallel group. I am not saying it cant be done but the cells should be preferably all from the same batch and the assembly should be meticulous. If there is a choice of 5 x 40ah cells and one 200 ah, the 200 is a safer bet and easier build. I'm confused, no wait... maybe I'm not... |
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