I'm thinking about buying an electric conversion kit for my bike but I'm rather confused how I would use this battery and charge it up (I'm new to this!)

 

here's the battery... http://ebay.eu/1qORcqc it's originally for the Mach 1 E-scooter

 

This is the kit I was thinking about buying - http://bit.ly/1BkYEzL

 

Maybe i'm making a mistake thinking about getting a lead acid battery... but it's roughly half the price of a li-ion battery pack...

 

also, here's another li-ion pack I was considering (although It is pretty expensive!... and the output looks like it needs a different connector to goto the controller instead of the +/- wires on other ones) http://www.aliexpress.com/item/battery-lithium-48v-48V-battery-bike-battery-48v-20ah-lithium-48v-battery-pack/1895914751.html

 

 

Thank you guys

Maybe i'm making a mistake thinking about getting a lead acid battery... but it's roughly half the price of a li-ion battery pack...

 

May be but have you thought about the weight & where your going to mount it.

Lead acid, 17.6kg (4 X 4.4Kg) that's nearly 39 pounds or in pedelec terms a sh#t load

You second choice, the lithium battery weighs 5.5Kg

 

Personally, for a "first build" I'd be looking at a complete kit with all parts from one source/surplier

Lead acid might look like value for money, but when you look closely it's a false economy. How do I know this? Because I have 8 x 14 ah batteries, barely used, sitting in my garage.

 

For a start, a 14ah SLA is roughly equivalent to 7ah of Lithium.

 

The other problem is energy density. For the same capacity, SLA is something like 4-6 times heavier.

 

Also, SLA's typically have only a few hundred charge cycles at the loads that a pedelec puts on them.

 

So:

 

If you want to save money, and get the best energy density, go for li-po. (Hobbyking but not without considerable research).

 

If you want easy going, good value then li-ion or perhaps LiFePo4 (BMSbattery, and others)

 

If you want to stick with SLA's, I'll sell you some :-)

thanks for the info guys! I think I might go for this one - http://www.aliexpress.com/item/50kph-max-speed-50-70km-distance-48v-15ah-LiNCM-battery-with-48v-1000w-ebike-conversion-kit/1969951454.html

my bike is a hybrid with 700x28c clinchers tyres.... i'll probably stick some decent 700x35c cyclocross tyres once I get the kit (i think the rim in the kit is slightly wider anyway).

I have acces to 990AH of lead acids right now, and we have piles of 2 years old ones available continuously... I used lead acid for some testing and just one ride on the road, before going for a LiFEPO4 12ah battery pack.

 

as mentioned above, they're a LOT heavier, and the usable capacity is very low. While the are "Cheap" to buy, they start to get expensive when they need regular replacement.

 

Even though I can get all the free ones I'd ever need, I think I'd probably have to take my battery weight from 5KG to nearly 30kg to keep the range, and reduce the voltage sag with lead acids, due to some of the steep hils I climb (and the extra weight I'd be carting!)

 

If you just want to try a kit out, some SLAs are good for testing, but expect to shell out for a decent battery if you get serious. I originally thought I'd just keep making SLA packs, but the more energy-dense batteries really do make sense (once to come to grips with the cost!)

I've ordered the kit with the 48v 15AH (~720Wh) Lithium-NCM battery... it should be delivered within the next week or so! hopefully it all goes smoothly