Q: How come these are higher capacity when the standard battery is rated '12A/hr'?
A: Because you can use much more of the stored energy in NiMh! You can only use about 65% of a Lead-Acid battery's power before its voltage drops too low to operate the motor! That's like having a petrol tank with the outlet pipe 1/3rd the way up!! With NiMh batteries you can use 90% of the stored power.
Q: what's the difference between the two?
A: The 9A/hr NiMh pack gives a litle more range than the original 12A/hr SLA, but is built from D-cells & weighs 3.5Kg AND IT FITS THE REAR CARRIER. The 13A/hr pack is built from F-cells: it weighs 5.1Kg but gives an increased range - 25 miles from customer reports.
Q: What are the drawbacks?
A: Mainly it is price, but we offer the best-priced high capacity batteries around! - Just get a quote from Yuasa, SAFT, Allbatteries.com or anyone else ! These batteries can't be charged or used at very low or very high temperatures. Use in normal weather is fine, but sub-Z and above 40C is a no-no
Q: How long will they last?
A: NiMh are much better suited to use on electric bikes than Lead-Acid. They 'like' being deeply discharged, and used with our smart charger they can deliver 400+ charge cycles and still keep 80% or their rated capacity.
Q: What about Li-Ion - isn't this 'the future'?
A: Li-Ion are excellent batteries for electric bikes, but the Currie uses up to 23 Amps@24V, and Li-Ion batteries that deliver this are too expensive and have safety questions: 'venting with flame' as the reports say!!. I am using Li-Ion with lower powered 36V hub motors (nano-motor), and they are a delight!