I currently use a Frog battery, rated at 24v, 8.5Ah. I'd like to use a more "powerful" battery. I'm thinking that a 36v would give me more power (for those hills!) and a 10Ah would give me more "fuel" (I could go further). However, I'm not sure whether a straight swap would be possible. I wonder if any experts or more knowledgeable people here could advise. Are there any risks/problems? Are there likely to be upper limits on the Voltage and Ahs I could go for? (Apologies - new to Pedelecs and I originally posted this in the "Electric Bikes" section but, on reflection, it probably should have been posted in the Technical section)

Most 24 controllers can manage a 36v battery without problems. The frog batteries are the esiest to upgrade because you simply clip in the 36v one and away you go.

 

In the worst case, your controller might blow, but replacement 36v ones are quite cheap.

 

Other problems are: Throttle LEDs will be on all the time, even when yhe battery is flat. 24v LCDs can give problems unless they're dual voltage.

Very many thanks for your reply.

The LEDs being on all the time would be a problem (I like to know how much life there is left in the battery as I'm cycling). Presumably the best option would be to change the controller which, hopefully, is quite straightforward.

 

Is there any way I can find out whether my LCDs are "dual voltage"? (And what is the difference between LED and LCD?!)

 

Finally, my ideal would be to have a situation whereby sometimes I could use the original 24v battery and sometimes use the 36v. Is that realistic (sensible!) - even if I I change to a 36v controller and ensure I have a dual voltage LCD?

Show us a photo of what's on your handlebars.Then we can avise you better.

Thanks. See attached. Hope that is what you were looking for - its the only "electrical" bit that is on the handlebars

PS: I should probably add (unless its obvious) that its the type of bike where the power only kicks in when you are actually pedalling (and switched on!)

That should all be OK at 36v. It won't be dual voltage. The battery display will always show full at 36v. You can get a waterproof LED voltmeter from Ebay for about £3 if you really want to see how much charge you have in the battery.

 

You can normally swap between 24v and 36v batteries as you wish.

 

Nothing is guaranteed. There's a small chance that your display or controller can't deal with 36v. Until you try it, you won't know. If you change to a 36v controller, it won't work with the 24v battery, but as I said, there's a fair chance that your 24v controller will work with the 36v battery.

 

If you get a new controller, you can get one with a throttle.

Great - thanks. Its obviously going to be a matter of "giving it a go" - which I'm happy to do. I suppose knowing how much charge is left (as I cycle) isn't a make or break issue - but I might look into the £3 voltmeter, which, presumably I can fit onto the bike so I can monitor the situation as I cycle. Having said that, the frog battery I currently have has a button on it that I can press to get a rough idea of how much charge is left.

 

I did forget to ask whether the charger I have for the 24v battery would also be appropriate for a 36v one?

I did forget to ask whether the charger I have for the 24v battery would also be appropriate for a 36v one?

 

No, you will need a 36v one.

No, you will need a 36v one.

 

OK. Thanks for that advice

No, you will need a 36v one.

.....but I should have asked, will "any" 36v charger do, as long as it has the right connection/fitting? Or should I be getting one of a particular type? e.g. I've seen one described as "36v 2.5A DC 42V 10Ah"

.....but I should have asked, will "any" 36v charger do, as long as it has the right connection/fitting? Or should I be getting one of a particular type? e.g. I've seen one described as "36v 2.5A DC 42V 10Ah"

 

A charger doesn't have an Ah rating, only a current/voltage rating. (I'm not suggesting it's not in the description, only that it's erroneous if it is).

 

It needs to be correct for the chemistry. 42v is correct for li-ion.

A charger doesn't have an Ah rating, only a current/voltage rating. (I'm not suggesting it's not in the description, only that it's erroneous if it is).

 

It needs to be correct for the chemistry. 42v is correct for li-ion.

 

Many thanks for your help.

When you buy a battery, it normally comes with the correct charger, so make sure you buy one with a charger, otherwise it will work out much more expensive.