Smile factor :)
Which battery pack will provide the most :) per mile?
To me, cost per mile of different battery technologies seems to be pretty close if you include purchase and replacement into the formula. So I would like to focus on how much fun I will get out of a battery pack.
I have Giant LaFree with the two 12 volt 12AH SLA batteries. I'm looking at replacing them pretty soon, they were new in 2004 and are getting worn out. I'm probably getting half the range I should out of them.
What I would like to achieve is more power/speed without too many mods. I'm thinking if I can get a replacement battery pack that puts out a few more volts over a longer period then the SLA's that came with this bike, that would do the trick. Has anyone done this? How did it work out?
Check your controllers capacitors and MOSFETs. The caps should have their rated voltage printed on their side the FETs specs can be found with sufficient Googling. They often are able to take an extra 12V. If not, replacing them is often a simple matter of desoldering out the old ones and soldering the new ones. LCV (low voltage cutout) won't work with the higher voltage batts, though.
Only problem you might have is if the controller has a HVC (high voltage cutout). You MIGHT be able to change/remove it, but you might have to just get a new controller.
As much as I like turbo buttons (I'm planning on using one myself), they're not a good idea if you don't know what you're doing. It's generally not a good idea to activate it from a dead start. Worse, you can screw up your batts if you throw it in when they're getting low. You might have overheating issues on hills and such, etc.
Ping's batteries are being used by a few over on the Endless Sphere. They keep us updated on how that goes.
It's under the name "Duct Tape Ebay Lifepo4s???". Be warned: It's a loooooong post (23 pages as of this writing).
I understand what you guys are saying, that's why I'm going to see if I can get away with only adding four extra volts to the system. The electrical components should be fine, I can not imagine them using cheap stuff in a expensive bike like the Giant Lafree. Anyways, I can imagine the caps would have at least a working voltage of 30 if not 50, same thing with the FET's, I can not see them putting a 25 volt product in a 24 volt system. It's probably going to come down to how good they have them heat sinked and how much air can get to them to cool them.
I hope there is no HVC, why would there be one on a bike with a SLA of a certain voltage.
The LVC should be built into a Lithium pack and I'm depending on that to keep the batteries in good shape.
I do not like the idea of a Turbo button, having to use the pedals to get power will tend to keep me from using up my range real quick.