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chinese import who knows

Posted: Sat Aug 11, 2012 9:28 am
by Helinut
Last week i traveled to harwich an bought an electric scooter moped looking thing, have searched the net and cant find the make so i shall just call it "the gink", it runs off 3x 12v 10a lead acid batteries, i have found i get about 14 miles though i want more, what is the best way to get more power out of this? i have heard about a lithium conversion but what are the benefits?
Thanks in advance for your time

Re: chinese import who knows

Posted: Sun Aug 12, 2012 9:48 am
by timpootle
Hello Helinut, and welcome!

Do you want more power (= speed and acceleration) or more capacity (=range)?

I think we will need more info, but from what you have told us the motor is running at 36V, and your battery is 10Ah (not 10A as you said).

So for more range you could install a 36 volt lithium pack of 20Ah, if you have room and deep pockets. £1/Ah/cell is a good guide, meaning £220 for that pack (assuming 12x3.2v cells of 20Ah each), plus a BMS of some kind. That should give you more than 30 miles range, because lithium batteries perform better under heavy load than lead-acid (go and look up "peukert" for the reason.)

More power usually means more volts, up to the point that the electronics burn out. Can you post a link to the advert you bought the bike from, or a photo of the motor and controller? This might give us an idea of the potential for over-volting that your bike has. Again, if you are happy with the SPEED and ACCELERATION you are getting, then stick to 36V and look at more Ampere-hours (Ah) to give you more RANGE. There is no limit to the size of pack you fit except physical size and weight to carry.

Hope that helps get you started. You don't have to be super accurate, but there really is no short cut to doing the basic maths, and getting a clear idea of what your Amps, Volts, Ampere-hours, Watts are giving you.

Re: chinese import who knows

Posted: Sun Oct 07, 2012 6:18 pm
by ChrisB
Cant go far wrong with a PING battery back, I've converted two electric bikes to run on ping battery packs and the improvement in range and power (not speed as thats limited) is amazing, both are running 20ah packs and they just go on and on and on.

The ping packs are quite nice as they are plug and play, includes all the BMS and charger, there not as cheap as buying the cells and making your own pack but you can be riding the bike within mins after charging it 8)