E300 Scooter mod from 24V Pb-acid to 36V Lithium-ion?

[EndlessFixer]

I'm considering upgrading my son's 12V lead-acid scooter with 36V lithium battery pack (with BMS) that I'll make myself. I know of a kit out there that someone in the US makes. I've seen an article or two out there (| Details | Hackaday.io) that discusses mods to bypass the current and voltage safety circuits on the Razor motor controller board, but that was back in 2014. You know of any controller mods or drop-in replacement controllers for these scooters? I have some extra lightly-used Lithium-ion batteries (18650, Samsung 2600 mAh, 5.5Amp) ready to build a pack for it. I have a background in electronics, not an engineer, so I would welcome any suggestions.

 

[MorbidlyObeseKoala]

Depending on how far you want to go (or how much you trust your son with speed) you can pop in a 36V or 48V brushed controller and swap in a krazy kart motor. Those are bolt in replacements on the e300 which I think is 24V stock. I hit about 22-24 mph on a 48V 1000W set up and I don't want to go any faster without better brakes. You can search your preferred voltage and brushed controller on Amazon and find some less than $50 options. The stock motor was cooked after about 20 minutes of the 48v controller power, you probably will get longer on 36V.

If you have one of the smaller razor scooters (200 or 100), I believe there's an example on here that uses an eskate motor and a small little vesc controller with pretty good results. That is a bit more spendy and a little more involved but a reasonable option I think.

The modified razor scooter facebook page has really good project photos and a fairly involved userbase. In case you run into something more specific to razor or want to see another person's solution on your same frame.

 

[rafalg]

It's easier with 24V (7S) li-ion battery, then you can use stock controller etc. And the scooter still goes a little faster than on acid.
Then you can replace the controller
Really cheap one is '24V 350W brushed controller' and it allows for throttle with variable speed control instead of on/off switch like the original scooter has.

Robot or human?

this one also goes a little faster than the stock one, and 'soft start' with a throttle is really nice.
Of course you can use 36V controller, but my experience with 36V was that the scooter is faster indeed but motor heats up pretty fast.
But i only have tested that on modded stock controller (to allow for higher voltage).
BTW for 24V you can pack 7S8P (56cell) 18650 battery into the box. I think 10S6P would fit as well if you want 36V.

 

[Matt Gruber]

i have 2 e300 that i upped to 36v the trick is to use a big rear sprocket and a new controller.
needs a longer chain too.