Battery problem..

[Johno1971]

Hi guy's and girls.
I not sure if I have posted this in the right place.
I have a problem with my battery, when out on my bike the power will cut out completely so I try turning the battery off then back on, sometimes it will come back on then cut out again a few yards further down the road.
During changin the charger light will cut in and out.
The battery is a 48v 10.4ah 1000w.
Could it be a bms problem!?
If so where would I get a replacement as a new battery is out of the questions at this time due to funds.

 

[Nealh]

Which type of battery and a pic.
Voltage charge when fully charged.
Battery age.

 

[Johno1971]

Which type of battery and a pic.
Voltage charge when fully charged.
Battery age.

Hi and thanks for the reply..the battery is just over a year old.
As for voltage when charged unsure at the moment as haven't tested it.
But when it works it still gives me the same range as when I first got it.

 

[Johno1971]

Just checked the voltage on each terminal (13s) and have 28. Volts per terminal.

 

[Nealh]

The BMS acts as switch when charging /discharging if it had an issue it would simply not carry out the task one way or the other.
Unfortunately (if an internal fault) it will mean opening the battery to try and find the fault and testing with a DVM.

From rereading your op I would first look at the battery and the receiver and check that the pin /connections are ok, as it is intermittent suspect a poor contact area. Signs of burnt or charred connections would indicate a shorting and poor contact.
A close up pic of base of battery and receiver pins would be good.

 

[cyclebuddy]

I had a bottle battery that looked very similar to that on my first e-bike - but a 36v 10Ah version. After a few months, it too had the same problems of intermittently cutting out when riding... but when the battery did work, it worked perfectly well. When charging, it too used to charge normally with a red LED, then for no apparent reason, the LED would turn green to say it was charged (when it wasn't)... then back to a red/charging LED again.

My battery was still covered by warranty at the time, and the issue turned out just to be a loose wire due to a bad solder joint (probably made worse by my overheating the battery by using too much juice up a steep incline). But it was easily fixed by re-soldering the defective solder joint on the battery board.

 

[Johno1971]

Just checked the voltage on each terminal (13s) and have 28. Volts per terminal.

Just tested the main out put and it's at 32.2v and that's at 3/4 charge.
Will test it again when fully charged ( having to disonnet the bms to charge it as won't charge properly)

 

[Johno1971]

Connector

 

[Nealh]

32.2 v is too low, min voltage should be around 42.9 - 44.2v so there is a charging issue somewhere.
The bms not charging means a cell group or two my well be low voltage wise, check the sense wires with a DVM at the jst connection block.
Write down the 13 parallel cell group readings, they should read as an example 3.7, 7.4, 11.1, 14.8 and so and so on.
Then post them on here.

 

[Deleted member 4366]

You haven't given us any details of your kit. Please tell or show us what you have. Generally, those batteries don't last 5 minutes if you use them with a 1000w kit, so it's probably completely knackered.

 

[Nealh]

I would discontinue the charge and first ascertain the 13 cell readings first.
For a balanced charge and for the bms to work correctly you will need to see the 13 readings to be close or nearly the same.

 

[Johno1971]

I would discontinue the charge and first ascertain the 13 cell readings first.
For a balanced charge and for the bms to work correctly you will need to see the 13 readings to be close or nearly the same.

Here are the readings...

 

[Nealh]

The readings aren't right you must be measuring them wrong.
Place your probes on B- & B1 for #1, B1 & B2 for #2 then B2 & B3 for #3 and so on and so for 13 cell readings they should ideally be in the range of 3.3v - 4.2v.

If the battery is knackered as d8veh has said then the measurements will be a lot worse .

 

[Johno1971]

The readings aren't right you must be measuring them wrong.
Place your probes on B- & B1 for #1, B1 & B2 for #2 then B2 & B3 for #3 and so on and so for 13 cell readings they should ideally be in the range of 3.3v - 4.2v.

If the battery is knackered as d8veh has said then the measurements will be a lot worse .

Yes sorry just checked them all again all are reading 3.9v

 

[Johno1971]

You haven't given us any details of your kit. Please tell or show us what you have. Generally, those batteries don't last 5 minutes if you use them with a 1000w kit, so it's probably completely knackered.

I have a pedalease x-cross x8c with 1000w rear hub and 880 led controller with twist grip accelerator and pas system, was brought as complete bike from pedalease.

 

[Nealh]

So you should have 50.7v output, probe on B- & B13 should agree.

 

[Johno1971]

So you should have 50.7v output, probe on B- & B13 should agree.

Yes mate just tested and b- & b13 = 50.7v

 

[Nealh]

Reconnect the BMS and measure again at the battery out put pins, there are four in your pic so you need the correct pair.
Or take the measurement on the inside of the pins directly off the + & -- wiring if you aren't seeing 50.7v there is a problem between the BMS and the wiring.

 

[Johno1971]

Reconnect the BMS and measure again at the battery out put pins, there are four in your pic so you need the correct pair.
Or take the measurement on the inside of the pins directly off the + & -- wiring if you aren't seeing 50.7v there is a problem between the BMS and the wiring.

Just tested and yes I'm getting 50.7v

 

[Nealh]

So far so good, apologies for all the Q&A's but necessary to try and find the issue. Bare with me as I'm in between recelling lipo packs.

Your 50.7v measurement was from the output pins or the wiring on the pins ?