Himiway 48V battery suddenly stopped working, yet not dead

[Pacto]

- Only used for a few months on a Himiway Escape Pro.
- Charger works fine, it has normal output voltage and I've tested it on another, working battery.
- Battery apparently charges since the charger indicator light turned from red to green after some time, and the battery output voltage measures 48.5V.
- There's continuity between the charging port and all of the positive prongs.
- Pressing the battery level indicator button results in all of the bars very briefly and faintly flickering; normally these bars would light up longer and brighter.
- Attempting to power on the display using the controller results in the display briefly flashing, and then nothing. This only happens when I try to power it on after some time; no response at all during consecutive attempts. The controller and display are both fully working since I've tested them on another bike.

What could be the issue here? The battery evidently isn't dead, and I'm assuming if the fuses are blown there would've been either no output voltage at all or no continuity between the charging port and the output?

Thanks for any advice.

 

[ElHegpah]

Your battery may be in a very dangerous condition. It is NOT fully charged.

Check your documentation, or fine print on the charger. Fully Charged voltage should be 50.4, or 54.6, or 58.8. Check charger output.

VERIFY that the other battery you tested the charger with is IDENTICAL in fully charged voltage to the first one. This could be EXTREMELY DANGEROUS.

Imagine putting 6 gallons of gasoline into a 5 gallon can.

Has the current battery been stored for an extended period? IMPORTANT you answer this question.

Also, what strange or unusual thing happened between the last time it worked and the first time it didn't?

Could be badly out of balance. Could have a broken or partially broken cell connection.

Could be one or more damaged or defective cells which are severely undercharged. Charging such a cell can have highly negative results.

Do not charge unattended. Recommend in a fireplace or bbq grill, outside if possible, monitor at all times.

You will hear a series of popping noises, and hissing, lots of acrid smoke, fumes, water makes it WORSE. You will not have a lot of time when it goes off, and it may go off at ANY time, not just when charging.

OR, you might just need a new battery in your voltmeter.

 

[Pacto]

Check your documentation, or fine print on the charger. Fully Charged voltage should be 50.4, or 54.6, or 58.8. Check charger output.

Charger output is 54.9V.

Has the current battery been stored for an extended period? IMPORTANT you answer this question.

Longest it sat without use is about a week.

Also, what strange or unusual thing happened between the last time it worked and the first time it didn't?

Nothing that I've noticed.

 

[Pacto]

Update: I checked the voltage from the battery again and it somehow has 54V now (I haven't plugged it in or done anything else since I last checked it). Tested and it works. I'm assuming this is the doing of its BMS? Anyone know how exactly it works?

Edit: Another update: same problem again after a few minutes of use. Could it be other components of the e-bike that are causing this, or still something with the battery?

 

[ElHegpah]

Get a better voltmeter. Need two digits past the decimal point. REPEAT - 50.40, 54.60, 58.80. MUST BE one of these. Variation beyond .01 indicates a problem.

Reading of 48.5 is very low. Charger output of 54.9 is a DANGEROUS overcharge for a 54.60 battery. 54V reading is NOT ACCURATE ENOUGH.

You say it is 54V NOW, after doing NOTHING. Last reported reading was 48.5. VERIFY THIS, There is NO component which could possibly cause such a change. Hopefully user error on the reading. Yes, I know EXACTLY how a BMS works. Not possible for BMS to increase battery state of charge by 6 volts. All BMS will do is DECREASE charge, very, very slowly. Months to make a change.

Get a new battery for the voltmeter, hold the probes STEADY, repeat each reading THREE times, or as many as it takes to get three IDENTICAL readings. Practice for consistency, and GET A NEW BATTERY FOR THE VOLTMETER. Weak battery will appear to function, but give inaccurate readings with significant variation. As will moving the probes around, also not getting a firm contact.

Contact Himiway IMMEDIATELY for possible warranty replacement. Good luck on that one.

One potential issue - Note the THREE (3) voltage possibilities I gave. These THREE (3) battery configurations, are described by sellers with just TWO (2) labels, 48V and 52V. Hence my caution on testing with a seperate battery.

Test battery button and indicator lights with battery REMOVED from cradle on bike. Charge and test same way. If you get dim or no lights on bike, remove immediately and test again. Possible issue with contacts on bike, these frequently corrode, get bent, or are not attached properly.

 

[smutboy]

if your charger overcharged the battery your bms very well could of locked your battery out to prevent it from overcharging and exploding. they also will cut the circuit to the battery if it falls below the cutoff voltage to protect the battery and it will cause it to not take a charge either.

if it was an over-voltage charge sometimes you can let the battery sit for a long time till it self discharges belove the cutout voltage but leaving a lithium battery fully charged and esp overcharged for more than a few days damages the battery and you will lose charge capacity.

the only way i know to drain the batterys below the cutoff voltage without having to let the battery sit for a few weeks or even months would be if the battery doesn't use individually protected cells that each have their own protection circuit inside each battery cell. (most battery packs that have their own bms usually don't use individually protected cells)) but you would need to be able to open your battery up and check each cell with a volt meter to check if you have any bad cells with either too much or too little voltage in each cell. But if any are overcharged or even if the whole pack is overcharged and the BMS is cutting power you would need to put some sort of load on the battery on the wires or tabs from the pack before they go into the BMS to drain the battery down below the cutoff voltage.

of if the bms low voltage cut off the battery from them falling under a safe voltage you need to find a way to put a few volts of power into each cell (called jump starting) to get them charged just enough to allow the BMS to unlock the low voltage cut out so they can charge again.

but if any of this sound to complicated to understand and if you don't know what you are doing safely. THEN I WOULD NOT RECOMMEND messing around inside a lithium battery pack being it can be very dangerous such as if you overcharge them or if you even accidentally short out the hot to negative terminals on any of the batteries can be very dangerous when it comes to such high amounts of voltage and amperage can start a fire or blow up the batteries. esp when you're working on the parts that aren't fused at all. and at best case even if a mistake don't start a fire or blow up your battery you can cause serious damage to the battery and BMS if you screw something up.

 

[Seaguy]

If I understand correctly, you have two identical batteries, and one is charging correctly to 54.6v and one is charging incorrectly. From what you've described My guess would be a bad connection to a cell within the pack, or a defective cell or a bad BMS. I agree with The above that this could be dangerous And you are unlikely to fix by Tinkering with it. Get the supplier to replace it.