Choices Choices; requesting input from the cognoscenti

[Diesel Dave]

Hi all, it's my first posting so I hope it's in the correct place (apart from my intro...)

I managed to blag myself an old 24v rear hub motor bike sans battery and charger, the frame is quite nicely made alloy with a battery mounting behind the seat post and in front of the rear wheel. Simple cable disk brakes and suspension front fork.

If this is a std type of battery mounting for which batteries are available - kindly let me know.

Now - in addition I'm a Velosolex rider, basically a bicycle with a 2 stroke motor driving the front wheel by friction roller.

Now, my thinking is....

1) Prove the 24v hub motor is still functional by obtaining/making a battery to fit.
2) Move the 24v wheel to the rear of the velosolex to help with hill climbs
3) Upgrade the Pedelec to a crank motor and add perhaps an additional rear carrier battery pack so I can join in the 50 mile Velosolex ride outs and wave the flag for electric power.

I would like to pick your collective brains on these ideas as sometimes one can 'tunnel vision' down a particular path and miss some obvious flaws.

I have a large stash of Samsung cells ready to make batteries with but don't have the required spot welder yet.

Cheers
Dave

 

[Deleted member 4366]

There's two versions of that bike. One has a conventional controller in an aluminium box, which sits in that compartment behind the bottom bracket. The other type has an unconventional one wrapped around the bottom bracket with just the connectors in that compartment.

The battery fitting is standard for a silver fish battery. Only the outer two pins are used. You can wire any battery to those pins or remove the plate with the pins in and run the wires straight through to the controller. The polarity is not standard, so check the battery with a meter and make sure that the positive terminal connects with the pin with the red wire.

http://www.ebay.co.uk/itm/Silver-Fish-Lithium-ion-Li-ion-Battery-Charger-24V-15Ah-Electric-Bicycle-Bike/162779526536?hash=item25e66a7588:g:~0oAAOSw3lFZecPu


You need to establish whether it's a brushed motor (2 wires) or brushless (3 or more).

You could try a 36v battery, which will make the motor 50% more powerful. Many 24v controllers run OK at 36v. If it pops, you can get a replacement 36v one for about £10.

 

[Diesel Dave]

Many thanks for the info.

I'll pop the frame box open and take a look inside and see what's in there.

 

[Diesel Dave]

Ok so new battery arrived today, unfortunately it's too large to fit in the frame mounting so I've wired it in from the rack.

Sadly the motor does not seem to want to play ball so I suspect there is a malfunction in the controller or wiring somewhere. The little power indicator on the handlebars lights up so power is getting through, it might be something as simple as the brake lever switches being sticky.

It looks like a 2 wire feed to the motor so I suspect it's a simple direct brushed motor.

I'll try powering the motor directly tomorrow and see if the motor is any good, if not then I'll probably take a drive down to Southend and see what kits Whoosh have available.

There's a scramble of cables inside the casing under the battery but no circuit board that I can see so it could be one of those with the controller wrapped around the bottom bracket (the casing is huge so could accommodate it easily.

 

[Nealh]

As you have splashed out on a new battery if you need a reasonable cheap kit £190 gets you a rear motor kit from Germany off ebay with KT controller and lcd etc, though a visit in person to Woosh may see you going home with a wheel kit minus battery.

 

[Deleted member 4366]

You can't power the motor directly if it's 3-phase. You'll burn the windings if you try. Did you determine how many wires go to the motor inside the outer sleeve?

 

[Diesel Dave]

Indeed, just the 2 cables into the motor so I think it’s a simple direct brushed motor.

 

[Diesel Dave]

Pedelecs seem to be like busses.....another bike has arrived after being offered too cheap to turn down...

So I now have a second 24v bike, this one actually does have a battery although it’s ‘challenged’ in holding capacity.

Luckily the other battery I bought does fit this bike, however thanks to the warnings from d8veh I have noted the polarity of the contacts is wrong so some corrections will be required.

So just need to add lights and a carrier and this one will be good to go for the shopping run.

For bike No 1. I’m tempted to replace the dud controller with a simple 24v relay as throttling a 24v motor doesn’t seem necessary - a simple push and hold button will suffice for the power control. Add a few skulls and some camo netting and a rattle can Matt black spray job and that should keep the local kids off it.

Onwards and upwards

I still need to get around to upgrading the moped to 72v and 3kw...the list is growing longer rather than shorter.

 

[Deleted member 4366]

After a controller on a 24v scooter went faulty, i wired in a direct switch, which seemed to work except that the motor burnt out shortly after, so i would advise to always use a controller. they're less than a tenner for you bike.