rlawn

Thanks for atht info. We have actually had the existing battery recelled by Jimmy as mentioned above, it is working much better.

to be honest I think the friends' bikes are bigger even than 10Ah, but if she goes from a faded 5.6 (probably more like 3-4) now to 7 I think we will be good. The friends' bikes are also big tyres etc and they do rough tracks, so if my wife really wants to start joining in we may need up with two bikes anyway but the citybike is great for shorter trips around town and road rides, and as it looks like a normal bike it feels much safer to leave locked to railings etc... I shall stick to sailing round the Irish Sea, once Wales lets me get back to the boat :-)

Thanks, yes that is what Jimmy is predicting, up to about 7Ah, hopefully all done in about a week's time :-) Thanks again for the link.

Thanks, we were looking... but the concern is they will also be a few years old, and so may have faded too..

We have spoken, he knew about the comms, has taken a few apart. Have agreed for him to recell it, so thanks for the tip :-) Richard

Thanks, that is very helpful, except for the bad news about Tx/Rx bit, which I must admit I had half expected :-) I had thought about your parallel option and there is room for the new wire feed in the controller I think. My concern would be that if the existing 5.6Ah seems to be considerably reduced (it does a bit less than 10 miles now, versus 20 or more before) then adding in say 6 or 8 Ah might be a bit unbalanced? So I will start with Jimmy, though approaches to other recell people have not worked (they don't do Gtech). Thanks again Richard

Hi, we bought a second hand Gtech Citybike two years ago for my wife and she is very happy with it, especially as lockdown eases off. But the already small (5.6Ah) battery has faded, and several of her friends have recently bought more powerful ones which means once they can cycle together again she will be dropping off half way! It seems impossible to buy spare Gtech batteries (? unless someone can help - this is the old type with circular button, but I would be happy to adapt it to use the square button type). Which means fitting a different battery, I guess a 10Ah one would do. As the controller is in the battery holder base on the Citybike this will involve some moving around of bits, but I am concerned about the electrical side. The Gtech controller has 4 wires running to the battery, see attached pic, the obvious red and black for power but the yellow and green ones for what? Clearly it will not be complicated for me to wire up the red and black from a non-Gtech 36V 10Ah battery, but I am asking for help with what will happen if yellow and green are not connected? Are they just wired to the switch on the battery (if so it is presumably solid state, so can it be replaced with a simple switch)? Or do they do something else? Any assistance on either finding a (new) spare battery or on the wiring will be gratefully received Richard