14s5p samsung 30q battery charging problems

jonnybee_123

100 mW
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Sep 27, 2019
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Hi I'm trying to test what is wrong with my battery ,
It's a 14s 52v pack for a ebike when i test i have 58v at the discharge leads. When I charge it tries charging for a few seconds then stops and the battery light flashes red. I would really like to get my head around this problem if someone can help me with some tests to carry out..I suspect it to be a bms problem as i have 58v at the discharge leads ?.its been left with out use for some months
Thanks for any help
 
Can anyone explain how to test the cell groups and the voltages I should expect the cells are Samsung 30qs it's a ( jumbo shark pack )..again thanks for any help
 

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58v sounds like a full battery- does it work on the bike?

Easiest place to test is the bms connector if you have access to it. Unplug the connector from the BMS, Clip the negative lead of the multimeter to the main battery negative Then measure one pin at a time on the BMS connector. Should be all the same voltage
 
No does not work when I turn the pack on the led indicator flashes red instead of showing the charge level through 3 green leds . I dont have the bms bluetooth app anymore does anyone have a link to it i have 4 volts across each each "p cell group??" Like I'm measuring In the pic...my leads not small enough to touch the pins without shorting to the one next to it...could the bms be the problem ? I have 58v coming out of the bms tho..can they lock down as a saftey feature is there a way to restart them
 
electric_nz said:
58v sounds like a full battery- does it work on the bike?

Easiest place to test is the bms connector if you have access to it. Unplug the connector from the BMS, Clip the negative lead of the multimeter to the main battery negative Then measure one pin at a time on the BMS connector. Should be all the same voltage
What would.cause the pack to.show 58v and not run the bike .faulty bms ? Could a short circuit hat c cause the battery to "lock out "
I've tested the pins and the voltage drops down for 58v to 4 v working my way through the pins..it increases by 4v each pins as I'm going through the connections In series I suppose is this right ? To me.this suggests the battery is fully charged but I'm new to batterys
I would Really appreciate it if anyone.can.shed any light on this .thanks guys
 
Found a app to connect to battery and its shows votage but no power....will charging the battery through the discharge leads solve this ?
 

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What is this telling you guys
I have voltage but no power ?
Dont understand that can anyone point me in the right direction anywhere I can read up on battery problems
 

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Hi when I turn this battery on it flashes red
When charging it flashes green about 3 times then turns to red and the charger stops
It tests at 58v at the discharge points and I've tested across the cells each parallel cell reads 4v when I connect to the bms app it shows this
 

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Voltage is useless as an indicator of battery capacity and health

i.e. whether it is at EoL.

A load test at CC to determine capacity is the best indicator.

Some battery chemistries only last a few hundred cycles even if cared for properly.

C-rates and average DoD% are two of the major factors.
 
goatman said:
sounds like bad bms, your battery temp is 13c? you might want to keep your battery inside at room temperature before using it each time

So With the voltages that I've got the cells appear to be ok ?
 
john61ct said:
Voltage is useless as an indicator of battery capacity and health

i.e. whether it is at EoL.

A load test at CC to determine capacity is the best indicator.

Some battery chemistries only last a few hundred cycles even if cared for properly.

C-rates and average DoD% are two of the major factors.

How would I carry out a load test
 
im not a bms person but usually amberwolf will step in and reply that theres a bad mosfet or driver? in the bms that lets some voltage through and that's what your reading but try and use it and theres nogo.

14s battery 14x4.2v= 58.8v, that's a fully charged battery so the bms is not letting you use it.
 
jonnybee_123 said:
goatman said:
sounds like bad bms, your battery temp is 13c? you might want to keep your battery inside at room temperature before using it each time

So With the voltages that I've got the cells appear to be ok ?
Voltage does not say anything about a battery' State of Health
 
Could still be early murdered, or POS cells to start with. Link to source, give full details of the cells, where they came from etc.

Most pack sellers are liars and thieves.

Rather than speculate, do a test, take the BMS out of the loop.
 
jonnybee_123 said:
How would I carry out a load test
Charge to full, 4.2Vpc

Rig up a load at the right voltage, ideally 0.3C or higher so it doesn't take too long.

Try to keep the amps rate constant, see exactly how long to drain down to 3Vpc.

Some hobby chargers have that functionality built in.

So example, If 10ah, a 4A rate, compare actual time to 150min (10÷4)

If only 50min, 30% SoH means past EoL, recycle.

If 120min, 80% SoH, good for a bit longer.

 
jonnybee_123 said:
No does not work when I turn the pack on the led indicator flashes red instead of showing the charge level through 3 green leds . I dont have the bms bluetooth app anymore does anyone have a link to it i have 4 volts across each each "p cell group??" Like I'm measuring In the pic...my leads not small enough to touch the pins without shorting to the one next to it...could the bms be the problem ? I have 58v coming out of the bms tho..can they lock down as a saftey feature is there a way to restart them

I solder sewing needles onto my probes for testing in tight spots
 
john61ct said:
OK, then either bad cells snuck in

BMS gone bad

or connections came loose.
Ok I aslo think there might have been some moisture in the pack perhaps as ther was some condensation I remember turning on and hearing a click then flashing red but theres no obvious signs of a short circuit from what I can see

Is there any way of proving the bms ?
 
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