1st Post and need help with Tohpson Euro Tourer fault please (long Post)

[m0bmn]

Hi All

I recently bought a Tompson Tourer (36v 200w) to get into electric bikes, When i bought it i was told that the battery was weak and would need to be replaced be for i could use it, ok i thought i can get 3 12AMP/Hr bats for about £65 and since i only paid about that for the bike i would be up and running nice and cheap, but........
now i have the bike and have had chance to do some checks i dont believe the battery is the problem, i have loaded the battery up with 120watts of light bulbs (3 x 20w 12v brake lights in series and then the same in parellel) and thebattery pack sits there in a blaze of light but now real drop in voltage on my multimeter, so next i put the battery back into the bike, with the bike on its stand when i twist the grip it spins up nice and seems to go nice and smooth up to its max speed, the on board battery indicator reads all is ok to, when i take it off its stand and it trys to drive along thebattery indicates flat on the leds and the bike trys to move but cant make it, just like a flat battery.
i have tested the cables that carry the power into the controller and put the meter on the point that they go into the controller box and messaged the voltage when the bike is tryingto moe but cant and the bikes leds say flat battery but i am only getting a couple of volts drop on my meter (normal 36, on load but not moving 33v)
anyone any ideas?? is it likly to be the controller? i guess the motor and hall switchs are ok since it runs fine on its stand with out any knocks or bump noise.
I hope someone can help,
sorry for such a long post.
best regards
Paul

 

[banbury frank]

Hi

You cant test the battery's like that not enough load

good battery's will red 38/9 volts

so NEW set battery's Good starting point The bike will perform better with fresh battery's

Also measure the voltage out off charger it will say on the charger label what this is

3 x RITAR 12V 12Ah / 15Ah Battery's for Electric Bikes | eBay

you can call them and pay by card if you don't have paypal account

These are for Electric bikes


Frank

 

[flecc]

As Frank says, you need new batteries. The bike's demands are far greater than those bulbs which aren't a relevant test.

 

[m0bmn]

Hi Again
i am spending this afternoon plating in the sun withthe bike and have more info that pointsto the controller to me,
with my current meter inline with the battery pos lead i find as soon as i turn on the bike it draws around 25 amps, thats before moving off, the battery drops by a couple of volts to 33v at this point but seems to hold there after. i know its a 200watt motor so even flat out thats just around 6 amps so somthing isnt right.
i disconnected all the wiring other than the power ,pos and neg to the controller, and measured the current again which was still the same.
the seems to say that the controller is playing up, but with all the wires connected i can still power up the motor which spins fast when on its stand so the controller must be working as regards the 3 phase outputs and hall swt inputs.
anyone any ideas what else i could try, i dont mind buying battiers if thats the problem but in the light of the above i am not so sure its that.
help please!!!
regards
Paul

 

[flecc]

At first sight that does appear the batteries may be ok Paul, but the precision of your meter may be marginally in question. The low voltage cut-out on e-bikes is often at around 31.5 to 32 volts, so your recorded 33 volts is dangerously close to that. If your meter is reading just 1 volt high, a battery cell could still be the problem.

That said, the 25 amps indicated discharge rate does seem extreme, unusually high.

 

[m0bmn]

Well to finish off the thread a last update
I did change the controller and it seemed to fix the problem, it cost about £45 from Thompsons.
The bats are still a littlw weak so today i got a new set (the ones Frank gave me the link to) and have been out on about a 10 mile ride, durring which , the chain came off! i the made a detour to my farthers home to fix that, the seat came loose, and the brakes started to bind! anyway by the time i got home all was sorted and i enjpyed the ride. charged the bike back up although it seems to have plenty of power left and will be off on a nothe 10 mile ride in the morning. thanks for the help and i expect in the next month or so i will be upgrading the bike too.
regards
Paul