Does this mean my battery is dead?

[DanAmes89]

I have a 60v 40ah e-bike battery that had 60 amps of continuous current. Used the battery with a controller, display, and motor wheel that were programmed for 80 amps of continuous current. They were all from the 3000w NB Power Conversion Kit (except the battery of course). At first, My display read 76% and the battery only produced 58.8v at a full charge. After trying to get these all of these to work together (I did not know the battery only had 60 amps of continuous current until after it died and I took it apart) My display went suddenly from 76% to 0%. Unless I had the battery charger plugged in. At that time, it would read 27% at a full charge. I unplug it, and it goes back to 0%. Plug it back in, and immediately goes back to 27%. Does this mean my battery is dead? Is it fixable? Is it even worth fixing?

 

[amberwolf]

The displayed information doesn't mean much unless you know what the voltages of the various percentages are supposed to be. It could just mean the controller / display are not setup for the battery you have, or that the settings have changed (on their own or accidentally/etc if anyone went into the display settings menus).


Your first check should be to use a multimeter with a good fresh battery in it (a low battery gives high readings) to check the actual battery voltage, without it connected to either charger or controller. Check at the battery's controller connector and write that down, then at the battery's charger connector and write that down.

If you get an unexpected reading based on what voltage the battery is supposed to be (a 60v battery is probably a 16s, which should read about 67v full), then you'd need to open the battery to do testing at the BMS and at the cells; we can work out what tests to do if that is the case.

 

[richj8990]

I have a 60v 40ah e-bike battery that had 60 amps of continuous current. Used the battery with a controller, display, and motor wheel that were programmed for 80 amps of continuous current. They were all from the 3000w NB Power Conversion Kit (except the battery of course). At first, My display read 76% and the battery only produced 58.8v at a full charge. After trying to get these all of these to work together (I did not know the battery only had 60 amps of continuous current until after it died and I took it apart) My display went suddenly from 76% to 0%. Unless I had the battery charger plugged in. At that time, it would read 27% at a full charge. I unplug it, and it goes back to 0%. Plug it back in, and immediately goes back to 27%. Does this mean my battery is dead? Is it fixable? Is it even worth fixing?

Dumb question but did you actually try to ride with it??? You know, like around your driveway? And see if it still works? Don't ride too far away if it does work...

I've only had two batteries and one is deceased. It read 50% charge for a long time no matter how much I left it on the charger. And sure enough it went from about 25-30 mile range (originally 650 Watt-hours) to about 10-15 mile range. So it did indeed drop 50% of its range after about 175 cycles. It lasted around 225 cycles and then completely died, suddenly. The most likely reason was that I would fully charge it for the first 175 cycles after only using 1/2 or even 1/3 of the charge. I didn't let it go down below 20% before recharging. The battery didn't like that. I learned not to do that with the 2nd battery!

I suspect you have a similar issue, and your range if the battery still works is going to be between 5-15 miles. Not a lot. Try it out, ride close to home in tight loops until the charge is completely out, and monitor how many miles you rode. Then save up for another battery if you don't like the range.

 

[BVH]

Rich, your battery died early BECAUSE you "repeatedly" discharged below 20%. That's a no-no for any Lithium chemistry battery. Even better, is to discharge to no less than 30% Depth of Discharge. Your battery will provide more lifetime charge cycles. There's tons of threads here on use and care of batteries.

 

[vaxt]

Disagree BVH, most lithium ion cells are rated at around 500 cycles at 100% DoD

 

[larsb]

At first, My display read 76% and the battery only produced 58.8v at a full charge. After trying to get these all of these to work together (I did not know the battery only had 60 amps of continuous current until after it died and I took it apart) My display went suddenly from 76% to 0%. Unless I had the battery charger plugged in. At that time, it would read 27% at a full charge. I unplug it, and it goes back to 0%. Plug it back in, and immediately goes back to 27%

That the battery is 60A continuous and controller 80A is an issue only if you’ve used it repeatedly at full throttle and with load high enough to reach the full current for a long time. That’s not so likely. What makes you think the pack is 60A continuous? Post a pic and a link to where you bought it.

58.8V corresponds well to a 14s battery at full charge so you might not have gotten a 60V nominal battery but instead a 14*3.6=50.4V nominal battery. It’s just a guess until the pack is checked for this.

How many cycles have you done with the battery?
And what do you mean by ”take it apart”?

It sounds like the issue could be the bms shutting off due to error protection. To know if it is that (and if bms should be doing that) we need to know:
-how many cells in series?
-voltage of complete pack?
-voltage of each of the individual cells

Once you know this then some good decisions about what to do can be made.

@BVH: what you state is not correct. Most of the quality cells have a stated cycle life at 100% depth of discharge given from new condition down to about 80% of original capacity, like this diagram for molicel p42a

Sure you get longer cycle life with less depth of discharge but a mandatory 20% or something like that is really not a requirement.