Problem with parts bin special unbranded bike

[fatts]

I took out a un named electric bike today, step through model. Looks new but prob been sitting around for a while. First prob charger u/s got another one sent. I took it out today,problems started when switched on not wanting to work to well The key has off and two on positions, position one throttle which works tilll about 10 mph, let go throttle whilst pedaling and motor goes faster ( 15mph ish) than you can pedal stop pedaling and cuts out as should unless throttle engaged but top speed back down to 10 ish.
I think the key same in the second postiton.
The pedal sensor also works sometimes in that you have to pedal a few revolutions to get power for throttle, but sometimes you dont need to pedal
There is also a button by throttle I am assuming a 2 speed button which does nothing in any position you try.
I hit a slight incline and it started cutting in and out with or without throttle and at other times. I did about 3 miles in all and the battery registerd about 37.6 volts at the end and has now been charging about 2 hrs. The battery pack is a 36v 12ah ish
The brake cut outs seem to work fine.
I wonder if anyone has any advice they can offer me as I am puzzled any help appreciated.
Well after being charged till full for 3 1/2 hrs it puts out 39.9 volts will recheck in the morning
regards
Fatts

 

[Blew it]

Sounds like the main problem is the battery, if it hasn't been regularly topped up whilst in storage, then it's safe to assume it's died an unnatural death. If the machine is fitted with battery level LED's on the throttle or separate display, did the LED's extinguish when the machine started cutting out?. If so, this indicates the voltage is sagging below Low Voltage Cutoff threshold of 31.5 volts....a sure sign the batteries need replacing.

If it's lead-acid as I suspect, then you could replace the three batteries for as little as £70- £100, there's alway plenty to choose from on Ebay.

The two position keyswitch is reminiscent of the MK1 and MK2 Powabikes, one position for pedelec only and position two for throttle only. I'm afraid I haven't a clue as to the function of the button on the throttle.

If you intend keeping the machine, then I suggest replacing the three batteries first, and then try to figure out how everything else works afterwards.

Have fun finding out.
Bob

 

[fatts]

Thanks for the input, I have a feeling it might not be the battery as after 15 hrs its still holding out at 39v and took about 4 hrs to charge from what I remember of sla's the quicker they charge the more naff they are so I assume that length of time meens they are still in usable condition. I had also only covered 3 miles on them
regards
Fatts