Heya,
I’ve got an art project on the go, involving a razor300e scooter. I would like to add a battery or watt evah works best. I also have a wee bit of welding to do, but sounds like it isn’t up and running here yet, so would like to discus what to do instead.
Hi Sven! It was fun talking to you last night.
IIUC this is the battery you have now… If you’re only looking to increase range, and you don’t mind a bulkier vehicle, you could just buy a second one and mount them in parallel… You might not be able to continue using the same charging system, but it would achieve your goal in a hurry, relatively safely.
But where’s the fun in that? 
Last night I was suggesting a system involving cylindrical Lithium cells, the most popular of which are codenamed “18650B” mainly because of their dimensions (18mm diameter, 65mm length). I think for your use case you’d want a “4S2P” configuration, with four cells in series per bank, and two banks. Each bank would yield 12V when fully discharged to 16V fully charged, and having both banks in parallel would give you a good capacity/range boost with the same voltage.
@RolandClarke has a very similar power system for his amazing robot project, if you ask nicely he can probably tell you about the BMS (battery management system) he’s using, which takes care to balance-charge the cells to preserve their life and prevents over-charging and over-discharging.
You might also need a relatively high-current-capable regulator board to bring the up to 16V of the battery pack down to the 12V expected by the rest of the system, not sure what’s already present under the bonnet. Maybe bring it in next Tuesday and we can help you tear it apart?
bought 4 of these for $3 each from Aliexpress. Worked like a charm. They can handle 10A each, so size accordingly.
Gday mistah
I was gonna bring scooter tonight , but it’s supposed to rain. Will try agin for next Tuesday
Gday
Curious if anyone with a vehicle is close to downtown and heading the vhs tonight . I have my scooter , which did work and now isn’t 
Thx
Sven
Heya mistah ,
Hope you’re well. I brought the scooter to vhs, and it’s pretty quiet tonight . Will leave it here and check back tomorrow night .
Hi Sven, I don’t get down to the space too often, sorry!
Trying to think of how to get your project moving forward… Maybe it’d be good to write up a new post about what you’ve got and what you’re trying to accomplish; we covered a lot of ground in person that won’t be visible to people on the forums. 
I have some time to kill now, so I’ll natter a bit.
One way to look at this is a modular architecture, where bits are plugged together and you need to unplug the batteries to charge them. My instinct would be to get a couple of beefy 4500+ mAh 4S LiPo batteries, the kind intended for large RC airplanes, buy or solder up a 2-into-1 XT60 pigtail, and use two of them in parallel, with a 12V switch-mode DC-to-DC regulator board downstream, to feed into the preexisting motor/control system.
HOWEVER
Lithium batteries are dangerous. You really shouldn’t charge or store them in your house/apartment. The odds of having a delightful crackling LiPo fire are low, but it can get really bad.
If your existing motor is designed to run on 12V, you’re going to need to draw a lot of current. These LiPo batteries can deliver huge current (see danger above) but the regulator that can handle enough current to accelerate a grown ass man might be expensive. You should also use battery management boards, which will cut out when the batteries get discharged too far (typically when any one cell is below 3V) and the ones Roland used might not be able to deliver enough current.
One safe way to move forward might be to use a current clamp meter to measure the current consumed by your current power system under maximum acceleration… And finally, lead acid batteries are really safe, you could just get a bigger one, or more of them.
We had a look at Sven’s scooter last time he was in. We went through the https://www.razor.com/faq/e100-why-does-my-scooter-not-run/ guide and determined that it was mostly likely the battery or charger that was the issue.
His batteries are two 12V 7AH lead acid units. Given that a replacement batteries on Amazon are $30 for one or $60 for two I would recommend just a replacement as opposed to building his own pack as the risk of fire is significant if not done properly.
Hey guys ,
I’ve talked to a fellow at grin technologies as well, it all seems to complicated and pricey. So am going to just buy replacement batteries and be done with it. I will upgrade when I’m not feeling overwhelmed by whole project . Thanks 
for your time and input , have a great day !
Maybe see you on Tuesday.
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