Extending the range of an electric bike...

In the last few days, I've bought a 22 inch electric bike 2nd hand for £120.

It's been pretty impressive so far imho.

Problem is, as people probably already know, is the battery...

At the moment, it does 12 miles at 17 mph quite comfortably with no input from the rider. (36v 12 amp lead acid battery)

Just curious to what you think of this idea of extending the range.

A leisure battery from a scrap yard 12v 110 amp - £30 A fast charger 22amp from Argos - £40 A 12v to 36 dc to dc convertor - £70 A current limiting diode.

ie 12v at 110amps, probably equals 36 volt at 30amp = 2 times as far = 25 miles, (taking into account the extra weight and the loss of electric convertion)

We need the battery ratings in A-h (ampere hours). Not sure that's what you posted.

What's the current limiting diode for?

Stay away from voltage converters, if at all possible.

What IS a current limiting diode?

Constant-current diodes are two-terminal field-effect transistors (sometimes called current-limiting diodes). I doubt that has anything to do with the bicycle.

Charles, WHY do you have your Microsoft Outlook Express

Outhouse Express is unpredictable. However, it is configured as you suggested (> in front).

Might be some dumb thing that I am doing?

Let's see how this reply gets posted.

Some messages come out like that - some quirk in OE I assume.

What's the Amp Hour rating?

What power rating? Needs to be greater than the bike motor can draw fully loaded. How efficient is it? Step up converters are normally inefficient.

In my view it would be better to use three slightly smaller 12V batteries in series. Buy three cheap chargers and seperate the batteries for charging. Don't recharge with them connected. Buy chargers with a float setting if possible to maintain the batteries over winter or between use. The battery will live longer. If necessary build a two wheel trailer box for the battery (and your lunch/tent?) if bike trailers are legal in the UK?