Upgrading battery

Wingreen

Pedelecer
Jul 28, 2015
194
59
Anglesey
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?