Upgading from 24v sla to 36v lithium

[minexplorer]

I fancy a little project for my missus.Before i converted my mountain bike with a bbs01 i used to poodle about for years on an old electric bike someone gave me.Its a dutch bike, totally the look that a woman wld like (used to sometimes feel a bit self conscious). It has a 200w rear hub,20 "wheels,no gears,just a 16t or 18t sprocket.The display is just a battery charge indicator.The battery is 24V SLA. Two wheelchair batts in the case which i replaced for 40 quid.It will only do maybe 10-12 miles now and anything more than gentle hills is kneecap popping. So im wondering if i bought a cheap lithium battery would it work or blow the controller.Also will it give it a bit more power.Seems a shame its just gathering dust now ive got the bafang.It would suit her,as she hates complicated stuff like gears.I can take the controller out if anyone can help and needs more info.I know theres 3 not 2 wire connections to the battery.Thanks

 

[Deleted member 4366]

It depends whether a brushed or brushless motor. The brushless ones normally work at 36v without any problems except that the controller's low voltage control and your battery indicator won't work properly, so you need a way to be sure that you don't over-drain the 36v battery. You can buy little panel-mount LCD voltmeters or an LED indicator panel for 36v.

 

[minexplorer]

It depends whether a brushed or brushless motor. The brushless ones normally work at 36v without any problems except that the controller's low voltage control and your battery indicator won't work properly, so you need a way to be sure that you don't over-drain the 36v battery. You can buy little panel-mount LCD voltmeters or an LED indicator panel for 36v.

Its quite a small diameter about 5" maybe the brushless type? The controller has nothing printed on it,just a small metal box 4" x 2.5".A group a 5 thin wires and a group of 3 thicker ones go from the motor to it as well as the PAS sensor wires..3 thick wires come out to battery connections, a red and black next to each other ,obviously pos an neg.But another red one slightly apart.Poss to the on off switch in the battery ? .Thanks d8veh

 

[Deleted member 4366]

That's brushless, so no problem.

 

[minexplorer]

That's brushless, so no problem.

Thanks d8veh for the advice. So far so good .Ive go a few final questions before deciding wether to fork out on a battery. The pos an neg are obvious as ive noticed the 2nd red to batt terminals is a bit thinner and for some reason has a spade connection halfway along it.So do i just tape the end of this or is it important ? If i fit one of those LED 36v displays or volt meter .where do i connect it.Spliced into the battery pos wire ,or to the original LED batt level display wires? Finally will the higher voltage over the orig 24v make it output higher assistance on inclines? Which its pretty gutless on. Ive no way of telling what the controllers programming such as AMP settings are. The higher voltage wouldnt blow the controller woult it? Thanks

 

[Deleted member 4366]

Running the motor at 36v will give you 50% more torque and speed. The motors are normally the same whether they're 24v or 36v, so it's no problem for them. It might be worth upgrading the controller with a 36v one and a LED control panel withthree levels of assist. They cost about £40 and give you a better control system thanthe single speed ones.

It's difficult to comment on your wiring without seeing photos, but it sounds like you have an ignition wire that needs to be connected to the battery positive ideally through a switch. If you stick with that controller, the voltmeter positive would connect to the switched (if you have a switch) side of the ignition wire and the negative to any ground. Any battery level wires coming out of the controller are switched on with the ignition wire, so you can use one of those and any convenient ground. If you have battery level LEDs on the handlebars, there ust be a local battery level wire and ground that you can use.

 

[minexplorer]

Running the motor at 36v will give you 50% more torque and speed. The motors are normally the same whether they're 24v or 36v, so it's no problem for them. It might be worth upgrading the controller with a 36v one and a LED control panel withthree levels of assist. They cost about £40 and give you a better control system thanthe single speed ones.

It's difficult to comment on your wiring without seeing photos, but it sounds like you have an ignition wire that needs to be connected to the battery positive ideally through a switch. If you stick with that controller, the voltmeter positive would connect to the switched (if you have a switch) side of the ignition wire and the negative to any ground. Any battery level wires coming out of the controller are switched on with the ignition wire, so you can use one of those and any convenient ground. If you have battery level LEDs on the handlebars, there ust be a local battery level wire and ground that you can use.

Thanks d8veh.The missus will only want one level of assist...MAXIMUM. If thats an ignition wire ,its activated by the switch on the battery ,which is the bikes on off switch. Just the way they designed it i guess.If i buy a 36v batt like the one i bought from eclipse bikes,which has a on /off switch, i should be able to ignore this wire and just connect the pos /neg wires.The switch on the battery being once more the bikes on /off.Sound logical?

 

[Deleted member 4366]

You can't ignore that wire if its the ignition wire because it carries the power for the controller and sensors. The main battery wires power the motor. You need to show a photo.

With single level PAS, whenever you turn the pedals, you'll get maximum power, which is very inconvenient. It means that you can't pedal slowly, and the bike takes off faster than you want.d at 24v, but you have 50% more power at 36v.

 

[minexplorer]

You can't ignore that wire if its the ignition wire because it carries the power for the controller and sensors. The main battery wires power the motor. You need to show a photo.

With single level PAS, whenever you turn the pedals, you'll get maximum power, which is very inconvenient. It means that you can't pedal slowly, and the bike takes off faster than you want.d at 24v, but you have 50% more power at 36v.

Your right on both counts . i did some tests.With both reds connected together it works perectly.Leaving the thinner ignition out,nothing.I havent tried temporarily fitting the other bikes batt for a test ride yet,but the wheel is certainly spinning with 50% more power /speed. Several places selling the exact led display ive got (BY-YF 1020 DISPLAYER) describing it for 36v bikes. I understand what you mean about it wont show when the battery has reached low voltage tho.I used to just ride it with the SLA until the led reached one bar an it cut out. I saw some displays that have the 3 PAS selection but presumably still no low voltage protection.They also have extra wires i dont know where theyd go...the PAS sensor? I cant upload a photo as my laptops bust ,am using ps4 browser . I can take the controller out again to dercribe the wiring set up in better detail , if that wld help. Much appreciate the help d8veh

 

[minexplorer]

As d8veh suggested earlier.As having no multple PAS it may be better to get a replacement controller with this function and also connections for adding a throttle.Can anyone point me in the right direction for an inexpensive one of the correct type. Its a 200w brushless rear hub motor, runnning 36v .Ive seen some on ebay, but not 100 % sure im looking at the right ones.As they usually say 250w ,500w etc ,an no mention of throttle connectability.Thanks

 

[Deleted member 4366]

All controllers work the same, though they have different connectors, so in the worst case, you have to cut off connectors and solder the wires. The important thing is to connect the wires in the right sequence because you can wipe out the controller if you get it wrong. You can't add a 3-level PAS control to your present controller

http://www.greenbikekit.com/motor-controller/250w-24v-36v-electric-bicycle-hub-motor-controller-with-led-meter.html

 

[minexplorer]

All controllers work the same, though they have different connectors, so in the worst case, you have to cut off connectors and solder the wires. The important thing is to connect the wires in the right sequence because you can wipe out the controller if you get it wrong. You can't add a 3-level PAS control to your present controller

http://www.greenbikekit.com/motor-controller/250w-24v-36v-electric-bicycle-hub-motor-controller-with-led-meter.html

Thanks d8veh that looks ideal. i can change connector ends easily enough.i wonder if it has the wires to add a throttle.The missus loved the one on my bbs01.Knowing her shed prob never use the PAS.

 

[Deleted member 4366]

The one linked above had the connectors for the throttle, the pedal sensor, brake switches, LED panel, motor phase wires, motor hall wires plus a few more that you don't need.

If your throttle cable has more than three wires because there's a switch or LED battery display on it, you need to identify the three that work the throttle, or more importantly, the one for the LEDs because the LED one will have battery voltage on it, so will damage anything else that you connect it to. That wire and the switch will be redundant with the new LED panel unless maybe the switch is used to isolate the throttle.

 

[minexplorer]

The one linked above had the connectors for the throttle, the pedal sensor, brake switches, LED panel, motor phase wires, motor hall wires plus a few more that you don't need.

If your throttle cable has more than three wires because there's a switch or LED battery display on it, you need to identify the three that work the throttle, or more importantly, the one for the LEDs because the LED one will have battery voltage on it, so will damage anything else that you connect it to. That wire and the switch will be redundant with the new LED panel unless maybe the switch is used to isolate the throttle.

Ill make sure i get a simple throttle with 3 wires.Thanks d8veh for all your help ,ive got all the info i cld need now.Whatever route i go down.First im curious to see how it performs as is with my bbs01 battery jury rigged.But looks like it will be really cheap to upgrade things with lots of advantages. Its a bit basic at the moment .My friend said he got it from Holland from 'lazy bikes.com' on ebay 4yrs ago.Just swapping the 8 kg sla for a 3.5 kg lithium is a dramatic weight improvement in itself.

 

[minexplorer]

Wow a test ride with my bbs 36v battery jury rigged was a revelation.Like a new machine compared to the 24v sla.Flew along and peddled with ease up steep inclines, that would have blown my kneecaps off with the 24v.
With my bbs i just use the top PAS 4 an 5. So apart from a volt meter for the battery protection, im not sure its worth doing more. One thing i notice with the bbs ,its faster uphill in PAS than the throttle.Which seems gutless ,tho it swiftly reaches 20mph on the flat. The only reason i can see a point in replacing the controller in this bike ,is to get throttle ability.So as to help my missus weaker leg muscles on hills.But will this too be gutless . Or is it just the way the bbs throttle has been programmed? Anyone know.Thanks

 

[Deleted member 4366]

It's the programming of your BBSxx.

 

[minexplorer]

It's the programming of your BBSxx.

So it wld be worth getting that controller u suggested an fitting a throttle then d8veh.It wld be better performance than my bbs throttle is at the mo? ( bought a programming cable for the bbs,jus got to mend my laptop first ). Thanks

 

[minexplorer]

I fancy a little project for my missus.Before i converted my mountain bike with a bbs01 i used to poodle about for years on an old electric bike someone gave me.Its a dutch bike, totally the look that a woman wld like (used to sometimes feel a bit self conscious). It has a 200w rear hub,20 "wheels,no gears,just a 16t or 18t sprocket.The display is just a battery charge indicator.The battery is 24V SLA. Two wheelchair batts in the case which i replaced for 40 quid.It will only do maybe 10-12 miles now and anything more than gentle hills is kneecap popping. So im wondering if i bought a cheap lithium battery would it work or blow the controller.Also will it give it a bit more power.Seems a shame its just gathering dust now ive got the bafang.It would suit her,as she hates complicated stuff like gears.I can take the controller out if anyone can help and needs more info.I know theres 3 not 2 wire connections to the battery.Thanks

Got around to finishing the bike today.
Bought a small panel mount volt meter for 36v use .Removed circuit board from original led battery display and cut top open for volt meter to clip in.Sealed with hot glue gun. Soldered wires to the ones for the original led.
Didnt bother with changing the controller.The bike is fine as it is .Its speed and torque are much improved over 24v ,but not so powerfull as to need multiple PAS options. Also after my experiences with the bbs throttle once wet,i wouldnt bother fitting one .I love riding this again,feels pretty pokey . A really useful bike now

 

[Nealh]

A Wuxing 108x with lateral lever is and looks more water proof compared to the other versions.
https://www.ebay.co.uk/itm/Thumb-Gas-Regulator-Throttle-E-bike-Speed-Control-Electric-Bicycle-Components-SP/263341995800?ssPageName=STRK:MEBIDX:IT&var=562355572067&_trksid=p2057872.m2749.l2649

 

[minexplorer]

A Wuxing 108x with lateral lever is and looks more water proof compared to the other versions.
https://www.ebay.co.uk/itm/Thumb-Gas-Regulator-Throttle-E-bike-Speed-Control-Electric-Bicycle-Components-SP/263341995800?ssPageName=STRK:MEBIDX:IT&var=562355572067&_trksid=p2057872.m2749.l2649

Yeah neal thanks you mentioned that throttle before .When i sort my bbs out im going to get one