Tag: lifepo

CITYSAX 160Ah LiFeYPO4 battery discharge and teardown (WHL #51)

Speaking of electric cars: A colleague recently bought a used electric car and (obviously!) contacted me in order to diagnose/troubleshoot it. Sadly he was able to sell it for a profit before we got it fully fixed, so no live data recordings, no power/torque graphs, no nothing to show here. But he left me a dead cell for which he got a replacement from the seller right away, as the traction battery had voltage dips under load that indicated (at least) one damaged cell.

If servicing individual battery cells sounds a bit strange for a modern electric car, that’s because we’re talking about a CITYSAX from a company that is conveniently named the same. […]

8th September 2019 8th September 2019 By Bzzz In No Comment

modellbaufuchs 26650 6S2P 4.6Ah LiFePO4 battery pack with balancer port (WHL #29)

And another one. I’ll churn these battery reviews out once per week now, even though I said I would rather go biweekly. It’s not much extra effort – charging, discharging and then plotting the data has to be done anyway, taking some extra photos and waffling on about it on my blog is a plus.

So this week’s item is a 6S2P battery pack, LiFePO4, rated at 4.6Ah. It’s from modellbaufuchs, which I just visited in preparation for this post. Not sure if they are still in business, as their latest news item on the page dates back to early 2015. […]

8th October 2017 3rd October 2017 By Bzzz In No Comment

O’CELL 26650 LiFePO4 8S 3.3Ah battery pack with BMS (WHL #28)

Same thing again – but different manufacturer. That’s what you get when you clean up your new lab… ;)

I know, might be boring to see another battery pack with almost identical specs (3.3Ah instead of 3.2Ah), but trust me, this is like night and day – or like quality China and Wan Hung Lo.

Of course these two batteries were purchased at the same time for the same thing, and they cost around the same as well. But (spoiler!): These two units work fine.

Top view:

Nice shrink wrap, proper label (shout out to O’CELL and their caring but not nagging sales people). […]

24th September 2017 3rd October 2017 By Bzzz In 2 Comments

26650 LiFePO4 8S battery pack with BMS (WHL #27)

This weeks article is another by-product of the ADC testing (WHL #26) from last week. Could’ve packed in there, but I wanted to share some remarks on Chinese battery technology…

So first of all, this isn’t a piece of kit that I bought myself. After testing two 12V/2.2Ah lead batteries from work that were sitting unused on a shelf for five years, I needed another victim. Those quality Panasonic cells were flat as Kansas – the LC-R122R2PG datasheets recommends 8.6V cutoff voltage at 3C = 6.6A or 9.7V at 1C. Fully charged, they delivered 1C at 7V or 1.5C at 2.5V at full charge – slow 10.5V discharging to 0.1C cutoff and recharging didn’t help much. […]

10th September 2017 10th September 2017 By Bzzz In No Comment