For bicycle mobile folk

[KC2UGV]

I just ran across this little gem: http://www.batteryspace.com/waterbottlelifepo4battery128v6800mah8704whforhidha logenbikelighttrial-techfemaleplug.aspx

6.6Ah LiFePo battery, in a water bottle case. Going to get me one of these to run my 817

[N8YX]

Neat find, Corey. I'll look at this more tonight. Big challenge is figuring out how to charge it via a dynohub. :chin:

[PA5COR]

No problem, our dyno's produce 6 -7 volts ac that can be doubld to 12-14 volts or more DC problem s it is at 6 -7 volts just 0.5 Amps, so doubling the voltage will leave just over 200 mA of currency at 14 volts for charging.
You can get some solar panels that will do 14 volts at 1 amp much easier and mount them on the bike or use rests to charge the batteries.

[KC2UGV]

Neat find, Corey. I'll look at this more tonight. Big challenge is figuring out how to charge it via a dynohub. :chin:


No problem, our dyno's produce 6 -7 volts ac that can be doubld to 12-14 volts or more DC problem s it is at 6 -7 volts just 0.5 Amps, so doubling the voltage will leave just over 200 mA of currency at 14 volts for charging.
You can get some solar panels that will do 14 volts at 1 amp much easier and mount them on the bike or use rests to charge the batteries.

Cor, are you sure it's a DC output? Most dyno hubs I've seen put out AC. If they are AC, it should be easy enough to make a rectifier bridge, however, you'll need a regulator as well.

[N8YX]

Cor, are you sure it's a DC output? Most dyno hubs I've seen put out AC. If they are AC, it should be easy enough to make a rectifier bridge, however, you'll need a regulator as well.
The SON, Schmidt and Shimano Alfine dynohubs (which is the model I'm using on two of my bikes) are all AC output. Converting this to DC and not wasting a lot in heating up a regulator calls for a low-dropout variant. If memory serves me correctly an LM2905 fits the bill.

Best approach to boosting the voltage to that which could charge a 12v battery would be the use of a small DC-DC converter. I looked into doing all this to charge my VX7 while on the trail. Somewhere I have some schematics tucked away as well as a list of mechanical parts required to make it all work.

[PA5COR]

>>No problem, our dyno's produce 6 -7 volts ac << end quote.
THey are AC dyno's producing 6 volts limited to 7 volts AC and 0.5 Amp = 3 watts AC power.
I aleady had a setup with rectifier and voltage doubler and that is why I know it produces about 13 to 14 volts DC after that but doubling the voltage will use some milli amps so you are left with about 200 mA at 14 volts.
Using the Dyno cycling you certainly notice the dyno running and have to use more leg power to get forward.




Cor, are you sure it's a DC output? Most dyno hubs I've seen put out AC. If they are AC, it should be easy enough to make a rectifier bridge, however, you'll need a regulator as well.

[N8YX]

I found a light yesterday which incorporates a USB charging port into its handlebar-mounted controller:

http://www.rivbike.com/Busch-and-Muller-Luxos-U-Headlight-p/ltd-11.htm

[kb2vxa]

Pardon my chuckles, I remember very well where that energy came from, my tired and sore 15 year old legs. I gave that up pretty quick and replaced the lights with battery operated ones. You can go with solar panels if you like, just keep the speed down so your bike doesn't turn into an airplane. (;->)