Portable solar panel battery maintainer - suggestions?

[SimonM]

Anyone out there use one of these: Amazon.com: Schumacher SP-200 2.4W Solar Battery Maintainer: Automotive or something better/similar?... I have a Maxum 2300SC with 2 12v Deka Marine Master DC27 batteries... although I have shore power available on my dock, I don't like the idea of lugging a mains charger to and from the boat (and the potential resulting electrolysis), so figured a solar maintainer might be the way to go to keep battery 1 topped up and feeding the automatic bilge pump?

[StillSinking]

This is interesting, has anyone used anything like this? Does it keep the battery charged when just hanging out with radio on and no external power supply?

[SimonM]

I went ahead and bought the model referred to in my original post... it works surprisingly well... I have it connected via croc clips directly to the battery terminal, but it also comes with a cigarette lighter option... not sure how (or how well?) that works, but the direct-to-battery option works pretty well

[shrew]

The current I in amps (A) is equal to the power P in watts (W), divided by the voltage V in volts (V): I(A) = P(W) / V(V)

So amps are equal to watts divided by volts [amp = watt / volt]

2.4/12 = 0.2 amps

10 hrs of direct sunlight would return 2 aH to the system.

This would be a solar trickle charger to offset the discharge rate of batteries sitting for extended period of time we no amp draw.

[mmwjr]

The .2 amps that shrew calculated is best current in a sunny day. A radio will use more than that so the solar panel will help but the battery is still discharged.

[Phillbo]

Why not install a marine grade charge on the boat since you have shore power available. I had the same boat with the 7.4L and the charger fit nicely in the engine compartment.