Finished bike - Mrs L likes it, as it gets her up the hill out of our village in second gear now, rather than on foot. Trouble is, have had to order a second kit for one of my bikes as I can’t keep up.
New 36v 250w BBS01B - seems underpowered?
Re: New 36v 250w BBS01B - seems underpowered?
That's a very alarmist view - do you have any credible evidence of fires being caused in this way (briefly charging directly via the discharge port)?
I'd agree that charging this way (in effect bypassing the BMS) isn't ideal, but to give a BMS a kick into life should IMHO be fine.
Happy to be corrected of course.
Without my stoker, every trip would only be half a journey
Re: New 36v 250w BBS01B - seems underpowered?
Just for clarity (and as Hemo said) the BBSxx range of motors do not have a torque sensor.
If you want a mid drive kit with a TS then you'll need to look at the TSDZ2.
If you want a mid drive kit with a TS then you'll need to look at the TSDZ2.
Without my stoker, every trip would only be half a journey
Re: New 36v 250w BBS01B - seems underpowered?
Absolutely --- I know cos I did it with a model aircraft battery but had it sitting in the middle of the garage floor ( painted concrete cos I'd been warned by other club members and my electronics background ) -- the burn marks are still there. The flame was so hot it melted the wing of a plane 2m away. There was nothing left of the battery just the foil it was wrapped in. Now this is only a 2200 ma battery ( ie 2.2ah) our bicycle batteries are 13Ah !bikes4two wrote: ↑14 Feb 2023, 8:58amThat's a very alarmist view - do you have any credible evidence of fires being caused in this way (briefly charging directly via the discharge port)?
I'd agree that charging this way (in effect bypassing the BMS) isn't ideal, but to give a BMS a kick into life should IMHO be fine.
Happy to be corrected of course.
There's plenty of evidence on YouTube of lipo's going up --
( model aircraft batteries don't have the BMS built in but it's done via the lipo charger using the balancing port and main connection terminals. What I did was to use a Nicad type charging method to try to charge a lipo that was too low to charge via the lipo charging method ie one or two of the cells had went below the safe charging threshold so when the lipo charger saw that it refused to charge it. I bypassed that by setting the charger to Nicad -- I had to fool the charger as well by using other settings )
Not alarmist -- informative for your own safety.
I am here. Where are you?
Re: New 36v 250w BBS01B - seems underpowered?
- We'll have agree to disagree then. The batteries you mention in your post are LiPo batteries which as I understand it, are rather different animals to eBike Lithium Ion batteries
- The trouble is with many YT vids and other anecdotal comments, you never know the background to the kit in question.
- I know that many say charging via the discharge pins is verbotten and maybe in certain circumstances it is not a good idea for the unitiated to undertake
- On my TSDZ2 build with a 10Ah bottle battery, the cheap BMS in it started cutting out intermittently (no, it wasn't a controller problem 'cos I changed that first), it was the BMS at fault.
- While waiting for a replacement BMS from GreenBikeKit I looked into the BMS discharge bypass mode used typically by electric skateboarders and did the bypass on my BMS (the Bottle battery has an in-built 20A fuse and the controller is set to limit current drawn to 15A and with an LVC of 31v which is basically what a BMS does on the discharge side).
- I still used the BMS charging port but after a while that stopped working too.
- About 4000Km ago I started to charge the battery via the discharge ports, so what, something like (Edit: 60 not 6) full discharge cycles (but done over many more charging/discharging events as I never run my battery flat).
- Every 500Km I would check the battery cell balance and they are just starting to creep apart so I will use an external balancer to keep the batteries in kilter.
Mind you, tinkering with batteries should not be for the unanitiated - you do need to know what you're doing - I'm a retired electrical engineer so I have an advantage over the average, but every day is a school day and I am still learning about ebike batteries, so I welcome any feedback on this topic.
Thanks All, B4t
Last edited by bikes4two on 15 Feb 2023, 2:19pm, edited 1 time in total.
Without my stoker, every trip would only be half a journey
Re: New 36v 250w BBS01B - seems underpowered?
( model aircraft batteries don't have the BMS built in but it's done via the lipo charger using the balancing port and main connection terminals. What I did was to use a Nicad type charging method to try to charge a lipo that was too low to charge via the lipo charging method ie one or two of the cells had went below the safe charging threshold so when the lipo charger saw that it refused to charge it. I bypassed that by setting the charger to Nicad -- I had to fool the charger as well by using other settings )[\quote]
Hmmm?
I note from the Battery University (and I can't profess to understand all of it) but the charging characteristics are quite different between Lithium batteries and Ni Cad ones. I wonder if your fire was caused by overcharging the voltage?
Without my stoker, every trip would only be half a journey
Re: New 36v 250w BBS01B - seems underpowered?
bikes4two wrote: ↑14 Feb 2023, 2:06pmNo I didn't use a different voltage -- it was a calculated attempt to lift the voltage to a point where the lipo charger could be used. That bit worked then I put the batteries back on the lipo charger. ( forgot to mention that bit earlier but I fear the damage had already been done -- as a side note we are supposed to stop using lipo's if they've been in a crash ) I knew this could go catastrophically wrong, which it did, hence the battery positioned where it was.( model aircraft batteries don't have the BMS built in but it's done via the lipo charger using the balancing port and main connection terminals. What I did was to use a Nicad type charging method to try to charge a lipo that was too low to charge via the lipo charging method ie one or two of the cells had went below the safe charging threshold so when the lipo charger saw that it refused to charge it. I bypassed that by setting the charger to Nicad -- I had to fool the charger as well by using other settings )[\quote]
Hmmm?
I note from the Battery University (and I can't profess to understand all of it) but the charging characteristics are quite different between Lithium batteries and Ni Cad ones. I wonder if your fire was caused by overcharging the voltage?
I am here. Where are you?
Re: New 36v 250w BBS01B - seems underpowered?
Lithium polymer ( lipo's ) are actually more stable than the lithium ion batteries in your bike, because the electrolyte is a gel instead of liquid ie a breach from negative to positive electrode is less likely on lipos. This is also why your bike battery is in a hard shell case ( and individual cells are in hard case). Our model batteries are soft and not in a hard case mostly for weight saving hence we are meant to get rid of them if they've been in a crash.bikes4two wrote: ↑14 Feb 2023, 2:03pm.
- We'll have agree to disagree then. The batteries you mention in your post are LiPo batteries which as I understand it, are rather different animals to eBike Lithium Ion batteries
- The trouble is with many YT vids and other anecdotal comments, you never know the background to the kit in question.
.
- I know that many say charging via the discharge pins is verbotten and maybe in certain circumstances it is not a good idea for the unitiated to undertake
- On my TSDZ2 build with a 10Ah bottle battery, the cheap BMS in it started cutting out intermittently (no, it wasn't a controller problem 'cos I changed that first), it was the BMS at fault.
- While waiting for a replacement BMS from GreenBikeKit I looked into the BMS discharge bypass mode used typically by electric skateboarders and did the bypass on my BMS (the Bottle battery has an in-built 20A fuse and the controller is set to limit current drawn to 15A and with an LVC of 31v which is basically what a BMS does on the discharge side).
- I still used the BMS charging port but after a while that stopped working too.
- About 4000Km ago I started to charge the battery via the discharge ports, so what, something like 6 full discharge cycles (but done over many more charging/discharging events as I never run my battery flat).
I respect your views and you have a burnt garage floor to prove your case. Conversely with my Lithium Ion battery I have not had any problems at all.
- Every 500Km I would check the battery cell balance and they are just starting to creep apart so I will use an external balancer to keep the batteries in kilter.
Mind you, tinkering with batteries should not be for the unanitiated - you do need to know what you're doing - I'm a retired electrical engineer so I have an advantage over the average, but every day is a school day and I am still learning about ebike batteries, so I welcome any feedback on this topic.
Thanks All, B4t
Tempering with the way they are charged is a definite no no.
It's the intensity of the heat they give off that's the thing -- I couldn't believe how much damage was done to stuff meters away from the tiny battery. It reminded me on the way a flare or firework goes off.
One chap at our flying club got his Jeep burnt to a shell by charging a lipo in the boot at the club -- there's a photo somewhere -- this was all despite my warnings -- I charge mine in a large ceramic dish with a lid for a ladle where my charging wires go in.
The bike battery is in a large stainless box I blagged from work
I am here. Where are you?
Re: New 36v 250w BBS01B - seems underpowered?
I am here. Where are you?
Re: New 36v 250w BBS01B - seems underpowered?
It seems like reprogramming the current worked for you. fwiw I had a similar problem on my BBS01b and was unable to reprogram the current so I replaced it with a BBS02b 36v 500w controller I could reprogram to 20a.