July 5, 20232 yr Do the battery's charge indicator LEDs include a WakeUp or On/Off button like on mine or are those rare? Chinese bikes don't normally have sleep mode in the batteries. That BMS is switched off. we just have to find out why. That resistor was clearly out of place, so it was a strong contender and needed fixing before doing anything else. It's always possible that a BMS has sleep mode, but in that case there should be something about it in the manual that came with the bike. Some BMSs switch off when they detect a fault and don't switch back on again afterwards, in which case they need to be reset. You can often reset them by removing the multi-pin connector and plugging it back in again, though if they have a separate connection to the B+ cable from the cell-pack, you sometimes need to break that connection too, so that the BMS loses its power. Some batteries have an on/off switch that switches the BMS on and off. Those switches can go faulty. We have to go all through these possibilities.
July 5, 20232 yr Author Disconnected white connector and cut cable to b+. All connected again and exactly the same state. I assume the 3 transistors in a row should have power on them? None at all on any pin of any of them.
July 5, 20232 yr Disconnected white connector and cut cable to b+. All connected again and exactly the same state. I assume the 3 transistors in a row should have power on them? None at all on any pin of any of them. The 3 mosfets are switched when they get around 12v on one leg. The 12v comes from a small transistor that's either switched when it gets 5v from a CPU or some other logic system.
July 5, 20232 yr Author The 3 mosfets are switched when they get around 12v on one leg. The 12v comes from a small transistor that's either switched when it gets 5v from a CPU or some other logic system. Time to bight the bullet and fit a new BMS I guess. Can you guide me to a suitable one? Thanks for everything - It's interesting and I'm starting to understand a bit more about these things now.
July 5, 20232 yr Time to bight the bullet and fit a new BMS I guess. Can you guide me to a suitable one? Thanks for everything - It's interesting and I'm starting to understand a bit more about these things now. Before doing that, I'd open the battery and see what voltage the cell-pack is.
July 8, 20232 yr Disconnected white connector and cut cable to b+. All connected again and exactly the same state. I assume the 3 transistors in a row should have power on them? None at all on any pin of any of them. No power there might be normal with low side switching.
August 13, 20232 yr Author Hi. It's been ages - I fitted a Daly BMS a few weeks ago - battery and bike work perfectly again. I enjoyed the soldering task and ended up with a very neat job - thanks for all your help. I now know a bit more about these things and the bike is great for exploring the Devon lanes. Cheers Edited August 13, 20232 yr by grumpyG
August 13, 20232 yr Hi. It's been ages - I fitted a Daly BMS a few weeks ago - battery and bike work perfectly again. I enjoyed the soldering task and ended up with a very neat job - thanks for all your help. I now know a bit more about these things and the bike is great for exploring the Devon lanes. Cheers[ATTACH type=full" alt="53327]53327[/ATTACH] Brilliant. It's very satisfying when you do something like that.
August 13, 20232 yr That's a nice looking step - thru. Good job on the bms , I hope it lasts longer then the two I fitted. If one day you find you have no power and only see residual discharge v's then it's new bms time again. Daly's have suspect QC , one can only hope they have upped their game.
August 14, 20232 yr Hi, also in need of controller advice! Pendelton Somerby, bought secondhand so no idea how the battery was looked after, came fully charged but had lost the charger, Test ride went fine, discovered that when stopping and turning back on again we get nothing battery pack shows full charge, but lights on display show 1 battery and flashing red led for the low mode on the 790 controller, ( Abnormal current apparently, no idea what that means in reality) However if left for 24 hours, no charging it will work fine, then the symptoms repeat themselves? Any ideas, I've taken the controller out and connections look fine but I'd like to replace /upgrade if possible, not looking to go faster! Cant find an exact match to the controller on line its an Santroll 36v mac current 15a rated 7A low voltage 31v, happy to replace that the display brakes and cadence
August 15, 20232 yr Author That's a nice looking step - thru. Good job on the bms , I hope it lasts longer then the two I fitted. If one day you find you have no power and only see residual discharge v's then it's new bms time again. Daly's have suspect QC , one can only hope they have upped their game. Thanks for that. The Daly was easy to fit at least . I bought two step through e bikes for not a lot as I couldn't confirm the batteries were any good. One bike just needed a charger and a mudguard and was brand new really - sold it for more than twice what I paid for both. This is the bike I'm keeping - I love the thing and it cost me nothing even with the BMS, gear cable and a mudguard. The 7 speed hub gear is a revelation after a lifetime of derailleur gears. I've ridden 26 very comfortable Devon miles today and have a ride in Cornwall planned for tomorrow. Thanks again.
August 19, 20232 yr Author Hi, also in need of controller advice! Pendelton Somerby, bought secondhand so no idea how the battery was looked after, came fully charged but had lost the charger, Test ride went fine, discovered that when stopping and turning back on again we get nothing battery pack shows full charge, but lights on display show 1 battery and flashing red led for the low mode on the 790 controller, ( Abnormal current apparently, no idea what that means in reality) However if left for 24 hours, no charging it will work fine, then the symptoms repeat themselves? Any ideas, I've taken the controller out and connections look fine but I'd like to replace /upgrade if possible, not looking to go faster! Cant find an exact match to the controller on line its an Santroll 36v mac current 15a rated 7A low voltage 31v, happy to replace that the display brakes and cadence Hi. Sorry I missed your reply. I'm starting to get to grips with how all these things work and I'd happily take a look but I'm in Paignton Devon. I assume you have a working charger for it?
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