Would like to know this too.
Darkstar, how did your test initially?
BYD LiFePO4 battery fiasco update
- Thread starter Will Prowse
- Start date
Darkstar, how did your test initially?
I am not going to throw anyone under the bus just yet as we need to do more testing and talking but we bottom balanced with a balancer and did manual charging and manual monitoring of cells during charge to identify how well the cells are matched. The balance during charging was anything but stable so I suspect the ones with dead cells is probably due to whatever management system they had being ineffective and allowing an over/under charge condition and subsequent damage. Just a guess. There are some internal resistance issues. We did some top balancing just so we could safely push the voltage up and get an effective test. Discharge was relatively stable and balanced so I feel we got some pretty good test data.
Mine showed here about 25V.
We basically wanted to minimize any BMS interactions during tests. Some might feel the BMS will magically make it better but IMO, if a BMS as to fight like mad to maintain voltages, there are deeper issues in battery health.
As Will pointed out in his test, the batteries are deeply degraded and probably the reason the data stickers were deliberately removed because we are dancing around about 50% degradation which puts these near trash can time. Yeah, they might make a few more pulls, but I suspect cells will start dropping out, which is what sounds like is happening. They are timed out!
Mine showed here about 25V.
We basically wanted to minimize any BMS interactions during tests. Some might feel the BMS will magically make it better but IMO, if a BMS as to fight like mad to maintain voltages, there are deeper issues in battery health.
As Will pointed out in his test, the batteries are deeply degraded and probably the reason the data stickers were deliberately removed because we are dancing around about 50% degradation which puts these near trash can time. Yeah, they might make a few more pulls, but I suspect cells will start dropping out, which is what sounds like is happening. They are timed out!
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Well, I truly hope not...
Mine were gotten from battery hookup, and they are all reading 23.6v, or 2.95vper cell... they are charging up but dropping to 26.41v, or 3.3v per cell...
at $300 per battery, and 3500Wh capacity, they are still less than 1/3 the price of a battleborn... but HEAVY...
they should perform in a light use setup power bank for years I hope...
Mine were gotten from battery hookup, and they are all reading 23.6v, or 2.95vper cell... they are charging up but dropping to 26.41v, or 3.3v per cell...
at $300 per battery, and 3500Wh capacity, they are still less than 1/3 the price of a battleborn... but HEAVY...
they should perform in a light use setup power bank for years I hope...
Holding stable voltage at a high state of charge is something we are testing now but I will say if you have one that won't hold above 26.41V, that points to serious issues IMO. What I do find interesting is bigbattery is not even advertising the fact that these are WELL USED on their site! And they are also removing the data sticker. NOT cool!
Then I see them on Ebay being advertised as "seller refurbished". There is no refurbishing going on! I also see most of these listings have had MULTIPLE title and description edits! Wonder what they changed?
I really want to give the sellers the benefit of the doubt but when I see outright false and fraudulent advertising on them, I have concerns.
Then I see them on Ebay being advertised as "seller refurbished". There is no refurbishing going on! I also see most of these listings have had MULTIPLE title and description edits! Wonder what they changed?
I really want to give the sellers the benefit of the doubt but when I see outright false and fraudulent advertising on them, I have concerns.
jasonhc73
Cat herder, and dog toy tosser.
I have 58 full days of use, 47 on a balancing BMS.
I have been using these batteries and cycling them every day twice a day. Charge and discharge - 5 days a week.
I bought a bunch of "4.0 - 4.5 kWh batteries", yes eight of them.
I would have never known I had less than what I was sold, had This "fiasco" and others not do full-on capacity tests.
I received batteries at 23.3V and 23.6V and was none the wiser.
I initially tried to charge them to voltage they were sold as to charge to (58.4/29.2), and every time after I charged them to that, they all self discharged to ~26.55V. After 3 or 4 days I gave up on that nonsense, and just settled on 54.4, which didn't even work. I just gave up and let 53.1(26.55V) be the number.
You cannot "balance" a broken cell, you can only work around it. There is no fix for a LiFePO4 degraded cell, it is forever a one-way chemical ion reaction that can never be undone.
Out of the 64 cells I have, I know at least 3 are total junkers, maybe 4. Because of these 3 junk cells, the 32 -36 kWh I bought only works out to be 14 kWh of usable batteries. I have sent the people I bought the batteries 3 separate emails since doing a deep cycle test, and still not one reply.
I have been using these batteries and cycling them every day twice a day. Charge and discharge - 5 days a week.
I bought a bunch of "4.0 - 4.5 kWh batteries", yes eight of them.
I would have never known I had less than what I was sold, had This "fiasco" and others not do full-on capacity tests.
I received batteries at 23.3V and 23.6V and was none the wiser.
I initially tried to charge them to voltage they were sold as to charge to (58.4/29.2), and every time after I charged them to that, they all self discharged to ~26.55V. After 3 or 4 days I gave up on that nonsense, and just settled on 54.4, which didn't even work. I just gave up and let 53.1(26.55V) be the number.
You cannot "balance" a broken cell, you can only work around it. There is no fix for a LiFePO4 degraded cell, it is forever a one-way chemical ion reaction that can never be undone.
Out of the 64 cells I have, I know at least 3 are total junkers, maybe 4. Because of these 3 junk cells, the 32 -36 kWh I bought only works out to be 14 kWh of usable batteries. I have sent the people I bought the batteries 3 separate emails since doing a deep cycle test, and still not one reply.
Like its been said before, these were originally sold as 5.63kWh now advertised at 2.8-3.8kWh!
Look at the cycle life charts and the 50% capacity of the BYD cell chart they MUST have 22000 cycles!
Just curious to see what the cycle by cycle losses look like for these. Are they about to fall off the cliff?
Look at the cycle life charts and the 50% capacity of the BYD cell chart they MUST have 22000 cycles!
Just curious to see what the cycle by cycle losses look like for these. Are they about to fall off the cliff?
Darkstar
Rain Wrangler
- Joined
- Dec 31, 2019
- Messages
- 339
Balance charging 14 BYD packs with ISDT Hobby Chargers
Follow along as I try to bring a bunch of BYD packs up to snuff after being in storage for a while. These packs were purchased from Battery Clearance Warehouse and seem to be in pretty good shape. The lowest initial voltage reading on any of the packs I got was 25.3, highest was 25.9...
diysolarforum.com
My initial test with no balance charge gave 3KWH.
But I had cells dive and/or climb at inappropriate times so I feel the unbalanced state of the cells limited the results. Guy from BCH said they absolutely need a balance charge after being taken out of storage. So I got an ISDT balance charger on the first pack now and will re-test once the cells are balanced.
I am also looking for bms options for a 48v battery made out of 14 of the packs... David Poz seems to use a single Chargery 16S for his bank of 8 packs. He also has the individual cells paralleled to each other with 10 AWG wire/inline fuses so that is probably how that works???
Who did you buy yours from?
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
I hear you and completely understand & appreciate how you feel, I would be quite percolated as well (to put it politely) and that has it's own hazards but we won't go there. They made ASSumptions based on testing Samples... Making ASSumptions usually leads to making an ASS out of ones self, time tested & true ! That being said, I don't know which company did what anymore but the fact that a couple are willing to stand up and take the hit (being honourable) and accepting the fact that THEY screwed up (making asses out of themselves) those companies keep the respect while the Deliquent Blamers & Shifter's need to be outted and removed from the marketspace.
I do think I ought to point out a small point though. This is essentially a New Business Sector - the used Lithium Battery Sales - and of course there is a leaning curve that vendors / resellers will have to get to grips with and soon. Sometimes these are hard / expensive lessons but those who accept they screw up & are willing to remain accountable for it says a lot, those that don't, well, there are always sheister's no matter where you.
I hope you get it sorted as does everyone else who got phookered. I honestly do not think it was intentional on anyones part BUT their responses are indicators as to who is honourable and who isn't and baddies need to be outted.
I have reached end of max politenesss mode.... yes, I can get quite colourful and in 5 languages to boot. Let me tell ya about Blue Air !
It is said many times that chinese products are junk, but in this case we bought from our own and was and is still being screwed. Some sellers do not even bother to respond. Have the money already so it seems a case of "screw you, bye bye money"
If you value your customers, please make it right. I am sure you bought these batteries cheap. I have seen these sell for 800 dollars on ebay.
This is not cool.
Icing on the cake is, not only am I NOT getting a response from BH, but I’m getting regular sales pitches for other products they sell via email...
jasonhc73
Cat herder, and dog toy tosser.
Drop shipped from BigBattery through Battery Hookup.
I noticed your subtext under your avatar...
Cat herder... you must be SKILLED!
And a new picture. Looking good Jason, thanks for your service.
Now I’m scared to buy two of these from bigbattery.com they are advertising 3kw @$699 each with $350 shipping: https://bigbattery.com/product/24v-lifepo4-power-wall/
Id be afraid to buy it, it had 4kwh in them last week!
