BLACKFOX'S BLOG : BATTERY BUSINESS

Repost from January 16/21

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Above: You can see that I now have 15 batteries. Numbers 1 through 10 are genuine Hailong batteries rated at 52v x 16 Ah. I purchased them from Grin Technologies and they have held up very well. I can rely on them to deliver 800+ Wh each.

Numbers 11 through 15 are from a company in China. They are advertised as Hailong batteries and are rated at 52v x 17.5 Ah. This rating is quite exaggerated. On average they only deliver 670 Wh of usable power. Testing revealed that these batteries only accept 13 Ah of charge after being completely discharged.

I bought these batteries at a low price but what looked like a bargain was not. If you shop local - and have a problem - you have a legal way to seek redress. But when you buy direct from China you are generally out of luck.

When I first contacted the company from China they dismissed my claims. But I am not without resources and after I brought those to bear, the company quickly settled.

Under the terms of the financial settlement I reached with the company I cannot reveal the company's name. The settlement agreement was that I got back cash plus I got to keep the batteries.

Additionally, the company changed their claim that these batteries are genuine Hailong batteries and now refer to them as Hailong "style" batteries although they still claim that they are rated at 52v x 17.5 Ah

Buyer beware!

Note: Battery #13 is particularly bad. It is so unpredictable that if it was a human I would say that it was psycho. It will crash without warning at any time. It doesn't matter if I am using it as a single battery or as part of a 3 battery pack hooked up in parallel. And if it is part of a 3 battery pack it will take out the other 2 batteries with it when it crashes.

But no matter when it crashes, if I put #13 on the bench and hook it up to a very low 8 W discharge I find that there is as many Wh as you might expect from a normal battery still in it which I am unable to access during normal use.

I have a theory about why this is so (perhaps a bad cell whose voltage sags prematurely on acceleration causing the BMS to cut out?) but I know so little about these matters that my guess could be pure nonsense.

Let me also add that when Grin batteries deplete there is always enough charge left in them to illuminate the bike's lights and the Cycle Analyst. When I am out in the countryside at midnight this is very helpful when I have to pedal home.

Contrast this with the troublesome batteries. When they crash it is lights out and one is left in the middle of nowhere in the pitch black unable to even see one's hand in front of one's face. This very disconcerting.

I now carry spare running lights that have their own batteries.

Update: Battery #6 now has the same problem.