Well, the EB-20-12 pack from ElitePower at $439 uses 3 ThunderSky 4 cell packs and as far as I can see, this is the cheapest and possibly the best value for LiFePO packs I have been able to find - and it ships from the US...

The SLA's I found are all about 12lbs each and the best Ah per weight seems to be the Leoch DJW12-26 (12V 26Ah).. Never mind any other options, I checked them all and a 20Ah pack would cost anywhere between $700usd and $2200 (A123 developer kit)... DeWalt batteries would cost more than that....

Still not sure why you would have such horrible performance on yer SLA's - I was reading about 4-6mi per Ah is normal, and to only get 3mi, you would have to be very heavy, not peddling and speeding uphill in a headwind with a fully loaded trailer. Doesn't make sense to me. Hopefully someone can add some real-world observations here.

I finally broke down and decided to go for the rear hub drive, I've already gone flying off a MTB at 40mph and I don't want to try my luck like that again, and I don't see a short term need to beef up the MTB frame before carefully considering other frame options (recumbent). The chances of my aluminum front forks giving are way too high.

I had originally had this idea of a front hub drive, trailer hub motor and this neat chain kit I saw from Czechosolvakia with a freewheeling crank. The power requirements would be huge and I've decided that's overkill, never mind slightly "illegal" in Canada due to legal speed limitations. At least with the hub motors and the kit, I can "set" a maximum speed to comply and confuse....

Still, back to the regen question and range... I can't say for sure, but it seems to me that the obvious problem with regen cooking electronics and batteries must be related to either voltage or amperage being fed back from the hub during the regen cycle. Certainly, I would have to be very careful with SLA's, and less careful with LiFePO. This brings the question...

I've been seeing LiFePo chargers up to 6A (http://elitepowersolutions.com/produ...products_id=79) and I'm pretty sure that an SLA would cook off if I charged it at that rate for a long period. (Actually, there's a 20A version of that charger) I'm not so sure that a solar charger is worthwhile (see: http://www.brunton.com/product.php?id=420 ) since it takes 12 hours to charge a 12V 40Ah car battery, it would take (estimated) 18 hours to charge a 36V 20Ah SLA, and I'm not so sure it could be "altered" to work with the LiFePO cells (see: http://elitepowersolutions.com/produ...products_id=74 )

The kit I'll be buying has regen, and uses the throttle and regen braking to charge, with two basic modes... You can use the throttle during regen braking to increase the regen, or not touch the throttle. I assume that not touching the throttle would "prevent" the possibility of cooking electronics and using the throttle *may* be very useful with LiFePO batteries - if I could ever get some sort of info on this "fast charge" capability. Apparently using the "fast charge" can shorten the cycle life of the batteries. That 16KM (10mi) downhill grade could come in useful after all... Shame there's a fully serviced campground at the base of the hill.