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Tech => Parts, Mods And Hacks => Topic started by: datu on September 07, 2017, 01:38:57 AM

Title: Chinese Batteries?
Post by: datu on September 07, 2017, 01:38:57 AM
I'm doing some research on a project ev motorcycle. A lot of the resources I found are 5 years old or older. The price of Lithium ion batteries has gone down, and I see some on aliexpress for pretty reasonable prices - for example, 4000Whr for around $900. Has anyone here had any experience with these Chinese batteries in a build?
Title: Re: Chinese Batteries?
Post by: Mattbastard on September 07, 2017, 08:18:19 AM
I have some experience with the confirmed China 18650's.  These are on eBay under the brand PKCell.  I bought a couple small packs, one set of 22mAh and a couple 3000mah.  I initially charged each with a XTAR VC4 charger, then discharged them with one of those small electronic devices with the resistor that measures the draw vs. a duration of time, and then charged them back up with the XTAR.  I can honestly say both sizes came quite close to their nameplate rating, within 100mah on the discharge, and the charge cycle.

I tried these because they were easy to get a couple of, and they didn't hide behind the fact that they're Chinese made.  Most of them Alibaba ones say they're Samsung or LG but... ya right. 
Title: Re: Chinese Batteries?
Post by: datu on September 08, 2017, 02:43:51 AM
They look good - too bad the company doesn't seem to do custom orders. There's better / larger capacities on alibaba than aliexpress, but the pricing is all over the place. I've reached out to a few for a quote, I'll see what they say. I'd love 72v 80+Ah but I doubt that's in my budget. It looks like alibaba has some sort of buyer protection, so it might be worth the risk to me. I'll see what the quotes come back as.
Title: Re: Chinese Batteries?
Post by: Mattbastard on September 08, 2017, 03:05:02 AM
The vendor I used on eBay has an offering for 1000, and a few other large quantities if you want. 

http://www.ebay.com/itm/1000x-Wholesale-PKCELL-18650-Rechargeable-Li-ion-Battery-3-7V-Genuine-2200mAh-/142385586136?hash=item2126d79fd8:g:aMQAAOSwImRYfxg0 (http://www.ebay.com/itm/1000x-Wholesale-PKCELL-18650-Rechargeable-Li-ion-Battery-3-7V-Genuine-2200mAh-/142385586136?hash=item2126d79fd8:g:aMQAAOSwImRYfxg0)

That right there wired up in the right size banks should get you around 10kWh.