if your in canada you can get 20v limn 6ah batteries at canadiantire for 109 each
i'm currently running 2 in my stock bat holder on my izip
many others are using them with great success
fully charged they are 21v each
each bat will pull 31a
are 5 cell
i was running 3 12v 12a
now higher volts @42 v 40 for sla
each bat is 2.76 pounds
i took off 24lbs
charge time from lvc(15v) is 3h
nice bats 1 year warrenty
can be run in series and parallel
thx wasp