Viability of starting up a battery cell business that gives real lifecycle testing results

[Maast]

I've seen so often here and other sites the "Is this a good battery?" question but there is no way to know unless somebody has already bought them and as far as I know nobody has done full lifecycle testing on their batteries they sell.

Chinese vendor published cycle test results are at best untrustworthy and are highly likely a complete fantasy with the charts ripped off from somebody else. I know I've seen the exact same chart pasted on several different Alibaba or Aliexpress batteries.

I've gone to CONSIDERABLE expense and time to build a large cell battery tester and am in the painfully slow process of life cycle testing of various batteries from various vendors prior to me buying fourty eight ~280AH cells and dropping a LARGE chuck of money on it. My tester is crude but it works really well.

I'm seriously considering setting up a Amazon site where I sell 120AH to 300AH battery cells for which I've done the full suite of tests and publish the results with each listing.
Maybe post videos showing the AH meter screen for a full discharge cycle to verify tests were really done.

I think it'd provide real value to customers to KNOW that the cells are good and will last for the rated cycles.

I also know that Amazon has a thing where you set up a site and send them your product and they handle all the shipping, etc "Amazon fufilled". That sounds like it'd be ideal as I dont personally want to be fulfilling orders, packing batteries, etc, etc etc.

Thoughts?

 

[John Frum]

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[Deleted member 783]

FORTY EIGHT 200AH batteries? Are you planning a hostile takeover of the sun?

 

[Maast]

I think this could be a valuable service.
I also think that it will be an expensive and time consuming process.
For a Lifepo4 battery are we talking >5000 full cycles?

Say that I'm producing smooth cells which are rated for 10 amps hours and 5000 cycles with a dishcharge rating of 1c and a discharge rating of 0.5c .
A full cycle test will require >15000 hours.

Do you intend to graph the charge/discharge curves?
How bout thermal data?
Will you test until failure?

You have given me an idea for youtube channel called "Battery Dyno".

I would just recreate the tests I've already done: Initial capacity at .25C, Initial capacity at 1C w/ temperature rise, and let it chug along on the cycler at .5C 80% DOD charge/discharge cycles until I get 300 or so cycles so I can extrapolate lifespan down to 80% of capacity. From all the graphs, charts and studies I've read the first 100 cycles degredation is a non linear curve, after that degradation is fairly linear. Call it two months of cycling per battery model.

FORTY EIGHT 200AH batteries? Are you planning a hostile takeover of the sun?

LOL, no I live near Tacoma WA and it's kind of dark in the winter. 45kwh of batt bank is 2 days of autonomy in those conditions.