Bike cutting out when battery on 3 bars
- Thread starter bikemerchant
- Start date
The easiest thing for you to try next is to do as Nealh has suggested in trying to manually charge the suspect cell(s) to the correct voltage and see if that then allows the BMS to do its thing and balance things properly with normal use/charging.
Anything else is going to be a lot more complicated in terms of stripping things down, desoldering etc (for which you probably would want to send the whole pack off to someone else like Jimmy as Soundwave suggested)
Thanks @GLJoe but it seems I need a solder kit?
If I don't need expensive tools to do it, is there a easy to follow video of it?
until you can get that bank of cells to the same voltage as the others so the bms can then balance them all again we wont know the condition of those cells.
you would need to drain it flat and then charge it again to see if all the cell banks are the same voltage if bank 11 is showing lower voltage then some cells could be damaged and need replacing.
you need a 5v 500ma charger to charge that bank of cells via the balance connector unplugged on the bms like in the last vid i posted but with a lipo cell.
Last edited:
Thanks @soundwave but the guy in the previous video you linked is using a solder kit - so it seems this is needed to charge up just the one bank of cells?
no you just need to raise the voltage of that one bank of cells so the bms can then take over and charge the hole pack together.
You don't have to. You just need some way of making electrical contact between the charger and the batteries.
If it was me, I'd just get a pair of wires with crocodile clips on each end.
I've used strong neodymium magnets to hold the wires onto the nickel strip to charge strings of cells with good success.
So you would cut off the crocodile clip on one end, expose the wire and insert it to the balance connector?
And the crocodile clip on the other end would clip one of the 2 prongs that go into the wall (going by the USA plug used in the video)?
the only thing you need to plug in to the wall is a 5v 500ma charger with the pos and neg cables striped.
disconnect the balance cable it has 1 black cable and the rest red for pos that goes to each cell bank
push the neg cable of the charger in to the black cable and the pos cable in to where bank 11 cable is and then it will charge that bank of cells.
also feel the cell bank when charging for any cells that are getting hot and if any start to rocket in temp stop charging as a cell could have gone bad and caused the problem in the first place as it only takes one cell to take down a hole pack.
No, that's not right. The 5v needs to connect across only the weak cell block, not all the way from 0v.
Two consecutive contacts in the bms connector, or direct to the two sides of the cell block.
Putting 11 cells across if will likely cause destruction or fire in the 5V charger.
Playing with batteries is dangerous. If unsure, stop until sure.
each cell bank is 4.2v so a 5v 500ma charger is all that is needed down the balance cable unplugged to that cell bank.
guy does the same thing in this vid to a single cell as out of balance.
The phone charge is 5v you can only charge 1s not 11s, SW the charger will blow.
The best option as the OP can't solder or doesn't have the know how is to simply cut the jack plug off, bare the wires and confirm correct polarity and then attach the wires only to #11 cell group directly via some strong magnets and if need be a washer (of about 12mm) as well under each magnet to hold the wire end flat.
Personally I think the OP should let someone who knows what they are doing to do the job, the cell group needs close monitoring and checking with a meter to ensure over charge doesn't occur.
The best option as the OP can't solder or doesn't have the know how is to simply cut the jack plug off, bare the wires and confirm correct polarity and then attach the wires only to #11 cell group directly via some strong magnets and if need be a washer (of about 12mm) as well under each magnet to hold the wire end flat.
Personally I think the OP should let someone who knows what they are doing to do the job, the cell group needs close monitoring and checking with a meter to ensure over charge doesn't occur.
Last edited:
Forget videos, just think about the battery structure. The black wire in the bms connector is at one end of the whole battery, not one end of the weak cell block. Both ends of the dodgy cell block are red wires in the bms connector, and they are beside each other.
This battery contains about the same energy as a cup of petrol. Equivalent level of care is needed or the house could burn down.
The Black wire is B- or 0v when it is used, every other sense port along the JST is a 1s and is accumulative in voltage if the Gnd is left in the B-. Try it for your self using a meter you will see you don't just get up to 4.2v. For single cell charging via the JST one has to place the 5v output wire in to the correlating sense port (in this case #11) and then the Gnd wire goes in to the sense port #10 so the charger only see's 1s /5v or less.
seen this guy on ebay and 100% feedback and will arrange pick up. imo it will be cheaper than what jimmy charges
cant do bosch batts tho
Ebike Battery Diagnostic Service | eBay
The list price in this advert is for a diagnostic service on your e-bike battery. We will diagnose the problem and provide you with options for repair. Should you wish to proceed with the repair the initial £40 will be deduced from the total cost of the repair.
www.ebay.co.uk
cant do bosch batts tho
The issue is getting hold of six genuine 35e's.
Nearly all good reputable sellers have no stock.
Nearly all good reputable sellers have no stock.
i know thought had a bright idea to go get some 18650 power banks from b and m and not one left and every sort of power bank was gone and nothing to buy
Samsung – eBike Batteries
ebikebatteries.co.uk
when i got some 3400mah Panasonic cells years ago they was £4.50 each buy 2 and got a free torch lol.
where do you check for cells? as so many fake ones out there these days but only need 4 atm.