Chinese 72v 70ah battery. Could it be real?

[Adrian_]

I'm currently building my third stealth bomber clone which will be my first 72v 8000w bike, the first 2 I built were 48v. I'm currently looking for the biggest battery that I can fit in those frames, my battery budget is around $1000. I found few listings on AliExpress for 72v 70ah batteries like this one: https://www.aliexpress.com/item/1005003163190836.html

For $1,400, shipped, it sounds like a good deal, for 70ah, I'm ok going over my budget slightly. I don't care who the battery is built by as long it has decent cells. When the battery gets delivered to me, the first thing I will do is replace the BMS with a good quality one and weather proof the battery myself and since I will be inside the battery, I can verify the cells and the real capacity. The listing I linked doesn't says what cells they are using so I messaged the seller and he said that they are LG cells, didn't specify the model, could be because the rep doesn't know that, maybe they are MJ1. Some other listings specify the cells as Panasonic.

I know there's a good amount of people on here with stealth bomber clones so I was wondering if I could get some advice. I'm not a battery expert but 72v 70ah for $1,400 sounds a bit too good to be true to me. I was expecting at least $2000 for a battery like that.

 

[999zip999]

LG cells. What LG cells 3amp or 20amp. LG is just a company name that makes 50 different cells or more.
Hard to get a decent battery anywhere unless you know there history.

 

[eMark]

The listing I linked doesn't says what cells they are using so I messaged the seller and he said that they are LG cells, didn't specify the model, could be because the rep doesn't know that, maybe they are MJ1.

LG Chem manufacturers no name brand lithium cells for other Chinese distributors (e.g. AliExpress, Alibaba, UPP, QWW Power, COBB Power Technology Co., Ltd., etc, etc). No guarantee they are top of the line "Grade A" cells, and no guarantee actual capacity is 70Ah, and certainly no guarantee your actual battery usage is good for 1600 cycles.

There's no definitive industry guarantee for what's an acceptable "Grade A" lithium cell (e.g. Samsung 30Q6 150 T).

Does the Chinese term "Guage A" in the following info ad have the same vagueness as the USA term "Grade A" :wink: :wink: ...

I'm not a battery expert but 72v 70ah for $1,400 sounds a bit too good to be true to me. I was expecting at least $2000 for a battery like that.

The age-old saying you get what you pay (buyer beware) applies to no name brand Chinese cells (IMO). On the other hand with TLC your $1,400 Chinese battery could prove to be a good investment. There's only one way to find out :thumb:

 

[skeetab5780]

Take this from someone who has bought over 50 Chinese/ebay batteries over the last decade, They all suck and will sag very bad and put out about half the listed C rating and capacity

And the cells they are saying are LG may be a junk cell with a fake LG shrink wrap over it. You can tell when the pack sags 10v when you apply a load to it

 

[eMark]

Take this from someone who has bought over 50 Chinese/ebay batteries over the last decade, They all suck and will sag very bad and put out about half the listed C rating and capacity.

Just goes to show how enticing is the price to take a gamble ... thinking the next pack is better than the intensive labor involved in sorting and builiding a spot-welded pack of used salvaged cells.

And the cells they are saying are LG may be a junk cell with a fake LG shrink wrap over it. You can tell when the pack sags 10v when you apply a load to it

It's not uncommon for Chinese to wrap the no name 1865 cans in a paper cushion so they can fit as many cells as possible close together (e.g. UPP). It's just as likely the cells in that $1400 pack are "Guage" B :wink:

That's why some would rather buy used salvaged Grade A cells for pennies on the dollar ... https://batteryhookup.com/ ... OR buy 100 25Rs for $385 ... https://www.18650batterystore.com/collections/featured-products/products/samsung-25r-18650 ... for a NESE 1865/2170 pack or design and build their own spot-welded pack (a worthwhile learning experience).

Note: FWIW "1600 cycles" probably means 800 charges and 800 discharges, but even that's a strectch unless both the charge and discharge cycles are only 1C :wink: