Got an e-bike battery from Aliexpress that doesnt meet specs. Money refunded but how to tell what I got?

[johnhmcneely]

I ordered a 48v, 50Ah, 50amp BMS e-bike battery on AliExpress. I wrote down dimensions and ordered a battery bag that would fit. It was supposed to come with a charger with delivery date 11 days away. I paid $153 for it including tax and shipping. No charger came so I had to buy one. The battery that came a month later was much, much smaller than the original dimensions. The wires coming out of the battery were so small and thin, I knew they were not thick enough to safely to handle 48v at 50amps. I complained to the vendor who stood by their specs. When I charged the battery and connected it to a 48v 50amp boat motor, it registered over 50v but as soon as I applied throttle the battery's tripped it off immediately. My money has been refunded but they don't want the battery back. My question is there a way to find out what I really got? Amp hours, how much continuous discharge it can handle? I hate to just throw it away. I own a multimeter and bought an energy meter for another battery.

 

[leffex]

I guess you got something worth 150 bucks. That would be 13 series and 2p of a pack sized 3 inches by 13 inches pack. If the dimension are very small that can be it. Value should be about 50 maximum. That's how they make a profit.

If you got the correct battery you'd have about these dimensions:*
14 inches by 13 inches minimum.

*(dimensions depend of products used to make it. 18650, 21700 cells or lipo pouches may differ in sizes)

 

[James340]

Open it.I assume it is shrink wrapped.I have a few &they have fiberglass panels taped to make a box then shrink wrapped.A 50ah battery would weight 20 pounds at least

 

[johnhmcneely]

Open it.I assume it is shrink wrapped.I have a few &they have fiberglass panels taped to make a box then shrink wrapped.A 50ah battery would weight 20 pounds at least

It weighs 9 pounds is 9 and 3/4 inches long instead of 15 inches

I guess you got something worth 150 bucks. That would be 13 series and 2p of a pack sized 3 inches by 13 inches pack. If the dimension are very small that can be it. Value should be about 50 maximum. That's how they make a profit.

If you got the correct battery you'd have about these dimensions:*
14 inches by 13 inches minimum.

*(dimensions depend of products used to make it. 18650, 21700 cells or lipo pouches may differ in sizes)

 

[johnhmcneely]

It weighs 9 pounds is 9 and 3/4 inches long instead of 15 inches

It weighs 9 pounds is 9 and 3/4 inches long instead of 15 inches

 

[amberwolf]

That's about 1/4 to 1/3 of what I'd expect for a 48v 50Ah pack.

I use a 52v 40Ah pack, and it's around 35lbs bare cells, and is roughly a foot by a foot by 3/4 of a foot. Good cells of more modern technologies could deliver more capacity in a smaller lighter package, but not by *that* much.

Based on typical too-cheap-to-be-true packs we've seen before, it's highly unlikely that good modern cells were used to build your pack; it's much more likely that it's made of recycled garbage cells salvaged from dead or failed batteries, and may even be random cells rather than all the same kind. Probably is also untested, so that the cells are not matched to each other and are unlikely to perform well together as a pack.

There are a number of threads in this subforum and others about testing batteries in various ways both to find out what they really are, and to find out what problems they have and fix them. Some are specifically about testing, and others are just troubleshooting a broken bike, scooter, or battery.

 

[docw009]

Give all the LxWxH dimensions, not just the length and one can figure out how many cells you have.

It sounds like 18650 cells. One cell is 18mm or .71 inch. A 48V battery is made using strings of 13 cells in a row, and that's 9.2 inches if the cells were stacked tight. Can't be 21700 cells as 13 of those is over 11 inches long,

The height is 65mm or about 3 inches high, right?. Give the width and we'll know whether it;s 13x3 (2.2 inches), 13x4 (2.9 inches) , 13x5 (3.6 inches) or 13x6 (4.4 inches). The weight of 9 pounds suggests 13x6. to me. Probably 10-12AH then using 2AH cells.

That's 78 cells for under $150, When cells cost less than a dollar, they're pretty bad, Like amberwolf says, do you really want that charging under your roof?

 

[johnhmcneely]

It weighs 9 pounds is 9 and 3/4 inches long instead of 15 inches

Here are the exact dimensions and photos: 10-inch long, by 4.5-inches tall, by 2.74-inches tall. It natively has a T connector and a charging port

 

[E-HP]

That's 78 cells for under $150, When cells cost less than a dollar, they're pretty bad, Like amberwolf says, do you really want that charging under your roof?

Cross checking, a typical 18650 cell weighs 50 grams, so doing the math with 78 cells, that’s 3900 grams or 8.7 lbs for the cells, so 9lbs with BMS and hardware sounds about right. I agree, junk cells.

 

[Chalo]

Cross checking, a typical 18650 cell weighs 50 grams, so doing the math with 78 cells, that’s 3900 grams or 8.7 lbs for the cells, so 9lbs with BMS and hardware sounds about right. I agree, junk cells.

It also means between 9 and 13Ah for typical new nameless Chinese generic cells. If they're recycled or salvaged, they could have a little more capacity or a whole lot less.

 

[MxusMick]

Sounds good for a future ebike.

 

[jumpman231923]

Here are the exact dimensions and photos: 10-inch long, by 4.5-inches tall, by 2.74-inches tall. It natively has a T connector and a charging port

What was the name of the seller ?? I got a couple packs that look similar and they were made up of 21700 cells they usually give you what you pay for they jus cheap out on the bms I have had t change out almost every one I have got off that site multiple sellers alot are all coming from the same factory jus different people selling them