I recently got about 15 solar lights without batteries (and may be getting more soon), the solar panels put out around 3-4 volts each but I'd like to use them to trickle charge a SLA battery. I'd prefer parallel wiring to allow the use of different size solar panels, and I picked up a small inductor from radioshack a while back and never used it, so what's the best way with a single 30v 150a logic mosfet, a handful of small NPN and PNP transistors, a couple 555's and nearly unlimited resistors and capacitors and a couple 2 amp 50v diodes to build a booster capable of handling say 2 amps input at 2-4 volts and supplying minimum 14 volts output at full power? For cooling (if needed), I've always wanted to submerge a working circuit in vegetable oil (this does work, right?)

I've seen many circuits on google but I'm not sure which one fits my needs.

 

Only two boost ics from LT, min input 2.7V@ 2.5A out

 

At 2 V minimum output from the solar cells, you might have to grow a small booster to generate enough volts to run the control circuit for the big booster. Maybe a 2-transistor multivibrator or a 1-transistor blocking oscillator.

ak

 

With an input 2A at 4V you are only dealing with 8W maximum. If your boost circuit is, say 75% efficient, you are only looking at 2W dissipation, and this will be distrusted among various components. So immersion in oil is a bit of overkill. In fact you might not even need a heatsink.

Bob

 

With an input 2A at 4V you are only dealing with 8W maximum. If your boost circuit is, say 75% efficient, you are only looking at 2W dissipation, and this will be distrusted among various components. So immersion in oil is a bit of overkill. In fact you might not even need a heatsink.

Bob

I figured the oil would be overkill but since I may be adding more solar panels I figured I should make it capable of handling the extra power.

Here's a circuit I'm looking at, would it fit my needs without the zener diode (no regulation needed) and maybe with a few different component values to get a higher output voltage?

 

At 2 V minimum output from the solar cells, you might have to grow a small booster to generate enough volts to run the control circuit for the big booster. Maybe a 2-transistor multivibrator of a 1-transistor blocking oscillator.

ak

What's the easiest way with what I have laying around?

Or I could run the booster control circuit off of a 9 volt rechargeable battery, charged by a separate 9 volt solar panel, or even of the SLA battery if this won't cause problems.