Replacing Cargo trike Battery - time for new motor or controller as well?

[6511iain]

Hello

I run a Nihola Cargo trike for kid hauling and shopping duties. For the last 6 years it has been used almost daily and now its time for the next service of the batteries.

Since 2014 we have run the following bought from BMS Battery.

Bafang BPM2 36V500W Rear Driving Bike Conversion Kit 201 - Customized - Wheel(rim) size: 26
36V 20Ah Li-Ion Shrink Tube EBike Battery Pack 200V~264V
30A controller

It has worked brilliantly - lots of torque for our steep hills around Bath and dragged kids easily well beyond the weight limit of the trike.

Thanks D8veh for some great advice on what to buy.

Anyway - battery is now past its best and I am about to buy a replacement from BMS

High C-Rate 36V 20Ah Li-Ion Battery Heat Shrink Battery Pack

Is it also wise to replace the motor & controller at the same time? I'm not sure of how long motors last & bearings?

If I do is the BPM2 stilll the best option or can I get as much torque from this:-

Q128C-135mm 500W CST Rear Driving EBike Hub Motor

In addition what would be the best controller if I was looking for a replacement? 30A seems to be what we need to get the grunt we want and we run with a throttle& break cuts outs but now other sensors.

The only repeating problem we had with the controller was melting the connections to the motor periodically. So something that can cope better with the load & heat would be great.

We have tried a BBS02 on another trike & it works well but doesn't seem quite as strong and wears the chains & sprockets much more quickly than the rear hub motor.

Advice or opinions welcomed.

Thanks

 

[Deleted member 4366]

I'm guessing that you have the KU123 controller. The S12S with S-LCD3 is much better, but you can only use it if your motor has hall sensors. It makes the motor smooth and quiet, and it has a really good pedal assist system. You'd probably need to change a couple of connectors to fit one or cut the connectors off and solder the wire. Who ever unplugs controller connectors anyway?

The motor will soldier on for a lifetime. Even if the bearings do go, they're dead easy and cheap to replace, so I'd leave that as it is.

The battery is a tricky one because you're shooting at a moving target. The one you had did pretty well for a cheap battery. I'm not convinced that the modern ones are any better. They're lighter and more powerful, but those characteristics are not so important for you, are they? Our friend Jimmy (Insat International) has some special cells (Boston) that are supposed to last a lot longer than normal ones. He makes custom batteries any size or shape you want and his prices are fair for what you get.
CALL: (020) 8361 1790 - ask for Jimmy

 

[6511iain]

Thanks for the advice. I'll have a look at the controller & talk to Jimmy.

 

[6511iain]

The S12S controller is rated 25A vs the KU123 at 30A. Is there an alternative S model that would work at 30A so we can retain the max torque? Looks like its an S12P or jumping to 35A with an S12SH.

Thanks

 

[Deleted member 4366]

You could use the S12SH. These controllers use current control on the PAS, so if you don't already have a pedal sensor, get one. Each of the 5 levels on the LCD gives a different power t the motor in increasing steps, so you can use low power when you want or high power for climbing.

 

[6511iain]

Thanks - any specific pedal sensor I should look for?

 

[Deleted member 4366]

I just use the cheapest. I've tried the various types, but I can't say that I've noticed any difference.

 

[anotherkiwi]

With the KT controllers there seems to be a difference in start up speed between 8 and 12 magnet disks. It may be completely subjective but I find the 12 magnet disk gives a smoother, quicker feel to start up.