mace1934
10 mW
- Joined
- Nov 12, 2007
- Messages
- 22
Gary,
Sorry for the delay; I've been away.
I've had that solar array for about 18 years. For many years it powered a well pump, but had been sitting unused for a while until I started using it for my bike. Six 60 watt panels; for the bike app. I have horizontal pairs wired in series. Each pair can charge a 10S A123 pack, or, as I usually do lately, 2 packs (either unmodified DeWalt packs or 10S bricks from DeWalt packs) in parallel.
I'll attach a little bigger pic of the panel charging the Rockhopper, and a micrologger graph of a pair of DeWalt packs being charged in parallel. They had been run down to a little over 1/2 capacity and had voltages of 33.07 and 30.75. After charge, their resting voltages respectively were 36.78 and 36.82.
Note that as the pack voltage rises to about 37, the current drops off to nil. Very convenient. No electronics needed.
There's more info on my experiences with solar charging A123 cells here (needs updating):
http://ruthnlarry.net/evs/bikes/26650/solchg.htm
There's also data on cell balancing on the site.
I wrote about some of these early results (as "mace") on the Tidal Force forum; I've since dropped out of that forum and I don't know if there are any of my posts left.
Most of my rides are into town, around town doing errands, then return - a distance of 15 - 20 miles. The reason my "mileage" is "good" is because I'm a slow poke, mainly because I have to get back with power to spare; the final 2.5 miles uphill is a real drain. I usually pedal some for a little exercise, but when I went to town and purposely did absoluely no pedalling, I still used only about 21 Wh/mile for the ride. The hub motor was at 148 degrees F on my return; it has been as hot as 160 degrees when I pushed it too far.
It's wonderful that you are working with EagleTree to help them come up with a unit more suited to our ebike needs. THANKS!
Best,
Larry
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Sorry for the delay; I've been away.
I've had that solar array for about 18 years. For many years it powered a well pump, but had been sitting unused for a while until I started using it for my bike. Six 60 watt panels; for the bike app. I have horizontal pairs wired in series. Each pair can charge a 10S A123 pack, or, as I usually do lately, 2 packs (either unmodified DeWalt packs or 10S bricks from DeWalt packs) in parallel.
I'll attach a little bigger pic of the panel charging the Rockhopper, and a micrologger graph of a pair of DeWalt packs being charged in parallel. They had been run down to a little over 1/2 capacity and had voltages of 33.07 and 30.75. After charge, their resting voltages respectively were 36.78 and 36.82.
Note that as the pack voltage rises to about 37, the current drops off to nil. Very convenient. No electronics needed.
There's more info on my experiences with solar charging A123 cells here (needs updating):
http://ruthnlarry.net/evs/bikes/26650/solchg.htm
There's also data on cell balancing on the site.
I wrote about some of these early results (as "mace") on the Tidal Force forum; I've since dropped out of that forum and I don't know if there are any of my posts left.
Most of my rides are into town, around town doing errands, then return - a distance of 15 - 20 miles. The reason my "mileage" is "good" is because I'm a slow poke, mainly because I have to get back with power to spare; the final 2.5 miles uphill is a real drain. I usually pedal some for a little exercise, but when I went to town and purposely did absoluely no pedalling, I still used only about 21 Wh/mile for the ride. The hub motor was at 148 degrees F on my return; it has been as hot as 160 degrees when I pushed it too far.
It's wonderful that you are working with EagleTree to help them come up with a unit more suited to our ebike needs. THANKS!
Best,
Larry
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