Can one rebuild a Raleigh forge battery, a Tranzx BL03 to be precise. Does the BMS have to be original?

[wojtek30]

I bought a raleigh force bike with a dead battery for cheap, I have 40 Cells and could easily rebuild the battery. Can I just build the new battery in the old casing and just plug in the + and - to the existing connectors or is there some additional steps that must be done, I would rather not use the original BMS since it could be damaged and not functioning correctly. (bike history unknown)

 

[StuartsProjects]

I bought a raleigh force bike with a dead battery for cheap, I have 40 Cells and could easily rebuild the battery.

How much experience do you have of re-building eBike batteries ?

 

[Nealh]

How do you propose to spot weld the cells ?
How do you propose to monitor hvc /lvc and balance during charging and discharging ?

On second thoughts does the Transx use CAN type comms/handshaking ?

 

[cyclebuddy]

You can buy pre-assembled cell packs for that battery on Ali, but you need the working BMS to transfer. Google shows that bike uses the older PST system which pre-dates the CANbus/LogiX era.

For not a lot more, you can (usually) buy direct replacement BL03 batteries on Yose/PSP etc and avoid the faff altogether.

 

[wojtek30]

You can buy pre-assembled cell packs for that battery on Ali, but you need the working BMS to transfer. Google shows that bike uses the older PST system which pre-dates the CANbus/LogiX era.

For not a lot more, you can (usually) buy direct replacement BL03 batteries on Yose/PSP etc and avoid the faff altogether.

Since its before the canbus era does that mean I can put any battery on it with any BMS? I have 40 LG mh1 cells from another ebike battery which stopped working due to the BMS being faulty.

 

[wojtek30]

How much experience do you have of re-building eBike batteries ?

I built a few battery packs before, none of them blew up.

 

[wojtek30]

How do you propose to spot weld the cells ?
How do you propose to monitor hvc /lvc and balance during charging and discharging ?

On second thoughts does the Transx use CAN type comms/handshaking ?

I have a stop welder, and I will use another BMS to do the hard work.

 

[soundwave]

if it has a dumb bms and no uart or can bus programing then all it will want is the correct voltage

 

[Nealh]

Since its before the canbus era does that mean I can put any battery on it with any BMS? I have 40 LG mh1 cells from another ebike battery which stopped working due to the BMS being faulty.

Yes any battery of a similar nominal voltage.
Be very wary of the Red Daly BMS , they are a bit hit and miss with reliability.

 

[wojtek30]

Yes any battery of a similar nominal voltage.
Be very wary of the Red Daly BMS , they are a bit hit and miss with reliability.

Is there any good BMS? Or should I just get one off of eBay for £15. They have enough amp capacity for my needs.

 

[Nealh]

I use to use annpower on aliexpress and can't say I ever had a problem.
The recently as I switched to 12s set up I found small footprint lion 12s BMS not easily available. The daly looked ok and small size but then I had two failures coincidently after reading about issue with them on ES.
After the second failure I changed to BeMuchSmarter brand.

Select carefully the one you need , do you need a switch option also make sure it has a balance feature. Most will use a rudementry passive balance feature that will keep cells in check if they are within approx. 0.05v during the charge . If one has cells that are harder to keep in balance then one needs an active balancer which will constantly monitor cell voltages.

 

[wojtek30]

Yes any battery of a similar nominal voltage.
Be very wary of the Red Daly BMS , they are a bit hit and miss with reliability.

Also, would I need an original charger for the original battery, or can I use a £12 eBay XLR charger. Thanks

 

[cyclebuddy]

Also, would I need an original charger for the original battery, or can I use a £12 eBay XLR charger. Thanks

It's not a standard XLR plug/socket: It's 5-pin/180 with a slot/groove and a 3rd wire connected, probably as a trigger for overcharge or overheat. If you're changing the BMS I doubt that third wire matters. Last time I looked, original TranzX chargers were £90+. I know some TranzX batteries do work with only a 2-wire +/- connection using that same non-standard 5-pin XLR.

 

[wojtek30]

Yes any battery of a similar nominal voltage.
Be very wary of the Red Daly BMS , they are a bit hit and miss with reliability.

I have finally gotten around to opening the battery, to my suprise all cells are at 0 volts. I believe the BMS has a fault which discharges the battery to 0. I also found another two wires which go into the bike, would those be important? Or is it just temperature sensing wires for the bike. I found a BMS with balancing, ocp, uvo, ovp on eBay for £15 so I will use that for my battery build