Originally Posted by met-head
I am building a recumbent trike (human powered) with an electric motor assist for hills. Sealed lead acid batteries are cheap but heavy, LiPo batteries are light but expensive, but what about Insight subpacks. How do they compare in terms of weight, capacity, and power delivery. I have my old IMA battery just sitting on a shelf. I'm sure there's a quite a few good subpacks left.
They have less capacity/weight than lead acid. They are used in the Insight because of other advantages.
For example, a single Trojan T105 golf cart battery, like my RV uses, delivers 220 A/Hr at 6 volts. The single stick voltage from an Insight pack has roughly the same voltage, or slightly more. If you could operate all 20 sticks in parallel you would get only 130 A/Hr. (They are in series in the pack.) The weights of the two approaches are approximately equal at 60-65 pounds.
IF you could design a regenerative charging system with your electric assist motor, then you might make the system work to your advantage. But remember, with energy conversions, you never get something for nothing. You would recover energy only while coasting or braking and that energy would have to be replaced by future pedal work. To top it off, the energy conversion is not 100% efficient, so extra pedal work would be required to make up for those loses.
Of course, you could design a simple "assist" system that did not regenerate the charge and simply plug in a charger between rides. Such a system could have advantages if your uphills are really tough and your gearing isn't adequate. The Insight sticks would have an advantage in that they can be charged much quicker by comparison. Just a thought.
I'm not a biker, but this is my take. JMHO.