emmo x E-scooter 48v 500w to 96v 5kw upgrade

[smeagol222]

I'm wanting to upgrade my "Emmo x" 48v lithium 500w scooter as I'm frequently carrying an extra person. Starting from stand-still up a hill sucks, there is no torque.
The most important thing for me is torque, I actaully dont mind being capped at 32km/hr, although 50 or 60 would be nice. To get more torque amps need to be increased? This means I need a higher wattage wheel and do the math (battery voltage x controller output amps)? either way I figure higher numbers the better, and I can limit the speed via controller later.

So I want to re-purpose a spare 48v 20ah lithium I have by combining them both to make 96v, upgrade hub wheel to 5kw (maybe less maybe more) and controller to 96v.
96v controllers seem to be priced (ebay) around $200, but say 1500w which may be too low. After some googling I found some on "kellycontroller" (not sure if they come with cables) and "goldenmotor" (chinese site). The golden motor ones seems to be for BLDC- not sure of it is different to hub wheel? both of these seem super expensive

The replacement wheel 5kw or so I'm thinking from "uumotor" (if you google '16 inch 5kw uumotor' its the second result)

The battery comes in a plastic box with handles which fits into the floor of the e-scooter. I've done measurements of the space inside and each battery, and both should fit once some padding has been altered. (see image)
I since I already have both chargers for each 48v I didn't really want to fork out for a 96v charger. I also thought that combining 2 batteries and using 1 charger might be a bad idea, since the cells wont be matching/balanced?

I was thinking just to add the charging port for the re-puposed 48v integrating it into the plastic box. There is a problem though. The current setup has a plug charges the original 48v battery and the same plug supplies power to the scooter. If I connect the batteries in series this would cause a problems when charging? Would I perhaps have to seperate this plug into 2 (one charging and one power output).

If the 2 batteries are connected in series only on 1 side (lets say positive) and they are hooked up to seperate chargers, is this going to create a bad thing?

I've tried to explain what I mean with some crap sketches.

I guess the other option (v2) would be to wire the second battery into the breaker, although this seems like the most simple approach I'd really like to have both batteries in 1 plastic unit and just plug in both 48v chargers.

-------------------------------------------------
EDIT

I Seem to have found some extra info about charging each one with 2 chargers - its okay to have one pole connected =) see image

 

[mistercrash]

You are planning to do something like I did, which is fun because you will be learning a lot on how to make these things go fast. But once you're done, you will have a bicycle capable of speeds like a small motorcycle, but you won't be able to license and insure it like a motorcycle. Because it did not come into this Country as a motorcycle but as a bicycle. Just so you know. (I'm assuming here you are in Canada because of your comment on the 32 km/h top speed) You will be spending a lot of money, and do a lot of work to end up with something totally illegal on the road. If you have a few hills to climb with a passenger on, your range might go down as low as 15 km with a 96V 20Ah battery. It may be better to stay at 48V to keep the top speed down and have 40Ah instead. Depending on which battery they are, they might not have the power to give you the amps you're after to get that torque needed to haul the bike and two people up the hill. I guess I'm saying you have lots of stuff to think about and figure out before you start spending. I'm trying to keep you from making the mistakes I made :lol:

Good luck
Ray

 

[smeagol222]

Yes you're correct, I'm in Canada. I realize that there might be some non-legal components here. I would be planning on using the controller to limit to 32km/hr when riding on the road, but I want the option for offroad.

What did you do exactly? I dont really need lots of range, but are you saying that 2x48v in parallel for 40ah I can get more amps out of it? Then perhaps all I need is an upgraded 48v controller that puts out more amps?

I would have to check the rating of the current 500w hub wheel. I really want to re-purpose this 48v I have already, and I like to work on projects like this.

 

[mistercrash]

Connecting both your 48V 20Ah batteries in parallel would give 40Ah and 48V. You could look into modifiyng the controller shunt and just doing this could give enough grunt to make you happy and it would not cost a thing. Maybe try this first to see if it satisfies you.

 

[smeagol222]

That sounds like a good idea. I heard it might be dangerous going the 96v way since each battery has is own BMS.

So if they are parallel I guess the BMS shouldn't get freaked out since there (should) be the same voltage. Would this mean more amps? Is there anywhere with instructions on how to shunt?

 

[ElectricGod]

What do you want to know about shunts? I can probably help you.