Ebike not working motor cuts out...

[bike4life]

So I have a battery from china... regular 48v 13 series 4 parrell... 18650.

When ever I even go more than 5 mph, the motor cuts out... After like 10 seconds of riding... Then What I have to do is unplug the battery and plug it back in and then it works. Then 10 seconds later cuts out. plug out, then in x60 connector.

I thought that would mean a bad motor controller so I put in another motor controller I had.
Same problem. So I was thinking its a bad battery cause what it the odds 2 controllers dont work....

When the battery cuts out, since i have the controller + and - wires to the battery on a terminal block, I can read the voltages with a volt meter. I get 1 volt...

The second i then unplug the battery from the whole ebike and measure the voltage I read 54 on the battery...

Anyone know what is going on here.

[E-HP]

You don’t provide enough information about your system to give proper advice, but from what you described, your battery isn’t able to provide the power your system needs and the BMS is tripping. Swapping controllers won’t help.

[docw009]

Your debugging points to the battery. When the output drops to nothing, it probably means the BMS tripped. They usually trip from undervoltage. You probably have a big voltage sag. That happens with undersized batteries, and also crappy batteries.

How many amps can the controllers push? Let's see the battery, motor, and controller listings.

[bike4life]

Sure thing. I actually had this set up working around 2 months ago... idk why it failed.
1000w bldc hub motor
and one of these batteries...
48v "20ah" who knows the real thing.

https://www.ebay.com/itm/Lithium-48V-99 ... SwcqxfhMx0

[E-HP]

Your battery isn't sufficient for your system. You're lucky if you get 10A from it, and that max rating is wishful thinking.

[AngryBob]

Depending on How Well it worked and How Long it worked and What Happened to it in between when it DID work and when it DOES NOT work and how MUCH DETAIL you can provide about all of these things, which would be a LOT MORE than you have supplied so far, you might have a very minor, easy to fix problem, to something more complex, to just needing to do better research before buying your next battery.

Problem is definitely located in battery. Unless you have left out some important details.

[docw009]

Crappy battery. It's 39 cells, 13s-3P. You might be looking at 6AH-7AH, not 99.999AH.

Really.

wow.jpg (103.14 KiB) Viewed 204 times

[markz]

Ah yes, good ole Chinese marketing at its finest. Like the $5 50,000 lumen lights in a 1sq. inch housing, or 10,000mAh 18650 can, or ebikes with ranges of 500 miles, or 18650 cans with a coin cell hidden inside the can. Ah yes, the best yet battery packs listed as major branded lithium supplier (Lg, Sanyo, Panasonic) when its really their D- quality QC rejects rebranded. Fun times buying from unknown sources on ebay, amazon, alibaba, aliexpress.

[Balmorhea]

Crappy battery. It's 39 cells, 13s-3P. You might be looking at 6AH-7AH, not 99.999AH.

It's typical (and stupid) for power bank and jumpstart pack manufacturers to claim an Ah capacity based on the sum of all the individual cells' Ah capacities. So under those labeling customs, if the 39 cells in that pack each have about 2600mAh, then the pack would have about 100Ah (times 3.7V). 13S arrangement would of course give you a real capacity of one-thirteenth of that.

I think it's a good guess that the cells are 2200mAh such as those used in hoverboards and many other consumer products. If so, that pack has nominally 6.6Ah and 317Wh of energy. Both the cells and the welded tabs are probably good for 2C discharge, or about 13A.

This is from the product description:

The battery discharge requirements:

1: Output 18 lines, length 200mm, red and black each one
2: Enter the outlet line leads to a 2.1 length 200mm
3: Rated discharge current: greater than or equal to10A
4: maximum instantaneous current: 40A
5: Maximum operating current: 13A

What they mean in "1" and "2" is mysterious to me. But the rest of it agrees with my hypothesis.

DO NOT discharge this pack at 40A. It's a terrible idea.

[E-HP]

Ah yes, good ole Chinese marketing at its finest.

Caveat Emptor. If you're going to buy off of ebay, at least look at the seller ratings. This one has two. One says he had a problem with the order, and the other says (in Spanish, I believe) essentially "where's my order?".

[E-HP]

I think it's a good guess that the cells are 2200mAh such as those used in hoverboards and many other consumer products. If so, that pack has nominally 6.6Ah and 317Wh of energy. Both the cells and the welded tabs are probably good for 2C discharge, or about 13A.

I think that's generous. I'm guessing 10A if the pack were healthy, but I'm guessing if it's cutting out at 5mph, then there are some bad cells, or the pack is so out of balance that it can't handle even a few amps.

[amberwolf]

Or like too many packs, it's made of recycled untested unsorted garbage cells (so yes, bad cells).

1: Output 18 lines, length 200mm, red and black each one
2: Enter the outlet line leads to a 2.1 length 200mm

What they mean in "1" and "2" is mysterious to me.

1 probably means 18g main discharge wires, one red and one black, 200mm long.
2...dunno, but I would guess it was supposed to say the charging wires are 21g 200mm long...maybe.

[AngryBob]

OP says it "worked" 2 months ago. That may mean it got 50 feet. It could also mean it had significant range, and maybe he crashed or dropped it in a swimming pool or body of water, or something else. Why the two month gap?

It is having LVC events, but when load is removed, shows nearly full pack voltage. So no dead or nearly so cells.

Could still be crap cells. Could also be generic, but decent cells, with possibly some bad internal connections, which possibly became bad after some unfortunate event.

We will probably never know, but for future readers, answering questions and providing full information can sometimes mean a reasonably inexpensive fix is possible and save you a lot of cash.

It could also clarify that you are, in fact, a total dumbass; but at this point that is the only reasonable assumption. Believing that ad copy is certainly a strong indicator.