Electric scooter conversion

While on holiday I saw an electric pedal scooter for sale in a mobility shop for £400, I had been looking for such a project for a long time I enquired within and they were willing to ship it to my house for the same price it was a bargain as a frame to work from befor shipping they let me use it for the rest of the holiday that way i would get an idea of what I had bought.


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I soon found out that it had dud lead acid batteries that that wouuld not hold much charge (3 12ah 12v) I could only get a couple of miles out of a full charge, I was going to throw them away so it did not matter, the acceleration from 0 was like a train pulling out of a station a new speed controller would take care of that, i was pleased to see it had a brushless motor with hall sensors making changing speed controllers easy.
There is plenty of room in the battery bay for 12 5 cell 5ah LiPo cells from HK, there is a lot of extra space in 3 compartments for extra batteries if needed, I will stick to the 12 to start off with this will give me 15ah at 72v(20s) with a capacity of just over 1KWh.

sounds good looking forward to this one oh and congrats you just hit 800 posts !!

To start off with I placed an order for most of the upgrades I wanted to do then I decided to have a go on it as it came.it would just give me one trip into town and back with the original batteries, once the LiPo's arrived I swapped out the lead acids for 10ah of LiPo's still at 36vthe range was better but the rest was the same.
Time to start ripping it apart to see just what I had bought after removing the battery I took the side panel off to expose the wiring, the power part of the wiring was just plain wrong to say the least the connectors were low power kettle types like you find on computers the power cables are way too thin coated with pvc not silicone, this was not the worst error that had been made the power cables were directly connected to the power input to the controller, the key switch works on the ignition as I would expect but with the power cables connected directly to the controller and as I confirmed there was a capacitor in the controller so the scooter was a battery killing machine, probably what happened to the lead acids that came with it.
I now have all the wires connected to the controller tagged, identified and how they worked/went to. The controller has now been removed ready for the new controller to take its place, for the lighting system a separate 36v battery pack has been made linking it in will be my next problem. The power cables will be upgraded and a separate battery isolation circuit withprecharger will be fitted this will be used at the start of the day then switched off at night the charging port is connected to the battery directly.

Yesterday I had my encounter with the local police, I was riding it as perfectly leagal speeds when I was pulled over when they realised it was an electric pedal scooter they let me go so no problem, I enquired why they had pulled me over it was due to me having no helmet and no number plate ( living on an estate where there are lots of people riding about on motor scooters with no helmet or no number plate) I was advised to put on a helmet no PROBS as I had one from a previous project a number plate was also advised even if it was false just make it obviously false. I now have and have fitted a number plate made at the local auto store it reads on two lines LECT RIC when put together and read you get LECTRIC this should make what I have obvious.

Hi
I've removed a lot of the panels on one side so i can now get to all the wiring, I've worked out how I'm going to get round the need for a 36v circuit as well as the 72v I had several ideas of how to achieve this a dc to dc converter would be ideal but no one does a 36v output converterone of the simplest and the one i have chosen for the moment is a separate 36v battery pack dedecated to the 36v items on the bike. I still had to have a way to control when the 36v was live this being controlled by the ignition switch the answer was to get a 12v psu and connect it to the main battery after the switch this would mean when the ignition was on you would get a 12v circuit as well, the 12v circuit would be used to power a relay that controlled the 36v circuit. The 12 v circuit would also allow for a 5v usb output for a phone or similar.
The battery PAC has now been reconfigured to 72v with a main XT90 as the power output, there are 4 balance ports one per 5 cells, to allow for charging from my RC charger a Hyperion 14 cell charger, there are also 2 36v power taps for charging as well.
The power wires in the scooter have been replaced with 10SWG wire with a pre-chaging switch and a power switch.
Geoff

Hi
The battery pack may have been configured for 72v but I still needed to fit the BMS and and wire all the balance wires into it.
Finally I have finished it I managed to fit in 12x5ah 5cell turnigy LiPo packs configured into a 15ah 72v battery pack energy size 1140Wh.