Quote:
Originally Posted by sreeve212
Thank you all for the tips! I will consider trying it. Should I decide to go forward with buying the module and testing it, I will post the results here.
Thanks again! (and feel free to keep leaving feedback  ) |
The 350 Farad series capacitor bank will fail to start your vehicle. My 400 Farad bank is just enough to start my 600cc motorcycle, which draws a paltry 80 cranking amps.
Here is the proper order of steps to take when considering replacing your battery with ultracapacitors:
1. Determine the amount of Ah it takes to start your vehicle
2. Determine the vehicles rate of parasitic draw in mA.
3. Decide how long you want the vehicle to be able to sit parked (assume no sun), slowly draining the reserve on the capacitor while still being able to start.
This post has the formula and I'm happy to help with the math.
4. Size your capacitor bank to meet the demands above, keeping in mind that you only get to use a fraction of the capacity before the voltage sags too low to be useful. In the case of my motorcycle, the minimum voltage required to start is 10v, and it probably sags to 8v when cranking.
Balancing is probably unnecessary since the capacitors bleed rate correlates to the voltage; that is, a capacitor at a higher voltage should bleed off charge at a faster rate than their lower voltage counterpart and approach a similar state of charge.
The balance circuit on the 350 Farad kit on Ebay is insufficient to bleed off the excess energy provided by a solar panel that outputs more than about 1 watt. Solar panels of any output would totally fry a non-balanced capacitor bank.
You could add higher output LEDs, or wire more diodes/LEDs in parallel to increase their ability to burn off the excess charge. The balance boards sold on Ebay for the higher rated capacitors would likely handle a modest overcharge from a solar panel.
If I were building for a car that lives outside in the sun, I'd probably get the 1500 Farad kit and balance boards and pair it with a 2.5 watt solar panel. I haven't run any numbers to see if the balance boards can cope with the excess energy, so don't take my estimation as gospel.
Here is my thread on the subject.