How to turbo charge an Urban Mover

[hech]

Hi, today I am looking for advice how to rejuvinate a rather elderly Urban Mover 36. Despite the name, the bike actually runs on 24volts and with an 8amp NMH battery, doesn't really run very fast. The controller is rated at 7amps and I suspect will not deliver much more than that even for short, peak bursts. I have a spare watt meter which I could fit to establish the actual power delivery figures but that involves fitting new connections to everything which I'm not keen on doing just yet.
It just seems odd that this oldish bike was designed with such a low power output in mind. The battery must be several years old so maybe the 24v system was much more effective when new. Does anyone have experience of 24v systems or Urban Movers or suggestions on how to get more out of this bike?

 

[mountainsport]

Sorry hech,

Definitely,i can not help you on this one,BUT! any photos? I do enjoy looking at them.

Mountainsport.

 

[Deleted member 4366]

36v battery on a rack; solder the shunt for 18amps - should go pretty well then, but you might want to raise the gearing because it'll be a lot faster. Your present 7 amps will probably be an actual 14 amps - the difference between max and continuous. If you want 30mph, gut the battery box and slide in a pair of 5000maH 6s lipos and change the controller for a 36v one with soldered shunt, but don't expect too much range.
Have a look at the Beastamatic thread. In principle, it'll be the same for your bike, but hopefully your controller compartment can take a bigger controller than the tiny Cyclamatic one.

 

[hech]

thanks d8veh, the beastamatic is a good parallel, even the controller compartment is the same unfortunately. We aren't needing high speeds, the power output is woeful, I can stop the motor wheel with my hand! Will try shunting the mod but suspect battery is struggling. The pair of lipos - do you mean in series or parallel?

 

[Deleted member 4366]

In series for 48v will give about 30mph +. The motor can give a lot more than it is at the moment. It should be OK with 20 amps, but you need a battery that can give that. If you want to stick with 15mph, you could try two 4S packs for a nominal 26v. You might be able to fit a pair of these in:
ZIPPY Flightmax 8400mAh 4S2P 30C LiFePo4 Pack

 

[hech]

thanks dave that's an eye opener. I thought the rc compact cells were a particular and volatile chemistry but there you have LiFePo at 20C. I wonder if these LiFePo cells need balance charging at all? Presumeably better lifespan as well.

 

[Deleted member 4366]

thanks dave that's an eye opener. I thought the rc compact cells were a particular and volatile chemistry but there you have LiFePo at 20C. I wonder if these LiFePo cells need balance charging at all? Presumeably better lifespan as well.

All batteries are dangerous if you don't treat them right. I think lipo problems are rare these days. they got their reputation from when people didn't know how to charge them. Now the modern intelligent chargers take care of everything - provided you use the right settings. A 20c battery will vapourise anything that attempts to short it out too -whatever chemistry.
These BC168 chargers balance while they charge, so no need for BMS.
AOK BC168 1-6S 8A 200W Super Speed LCD Intellective Balance Charger/Discharger | eBay

 

[hech]

Yes but the point I was trying to make is that whereas bike batteries are normally 1-5C, these new lifepo rc cells are 20-30C, just like rc lipo. way smaller too. Is it jus because they are pouch cells?