[Elecraft] Solar panel question

[Mike]

> Question:  If I want to add a solar panel to the system to charge the
> same battery with a bit more "oomph", is it safe to merely place the
> new panel in parallel with the old one, or is some sort of intervening
> circuitry necessary?

Hi, Bob. Putting second panel in parallel (kind of addicting, isn't it?)
should pose no problems and no additional circuitry, assuming:

1) the max charge current rate of the battery is not exceeded (I don't
think Don's controller has current limiting, but I could be wrong) 2)
the max charge current of the Don's controller isn't exceeded

Other than those two, you should be set. Parallel them at the panels and
ensure your cable coming off the two is plenty heavy to handle the
current.  Actually, let me rephrase that. The current from two panels
isn't anything to worry about - even 18 gauge can probable handle it.
The problem is the same for one panel or a dozen: voltage drop. DC
voltage drop at 12 volts can be pretty dramatic, so the cable ends up
being far heavier than common sense would seem to dictate. Since you've
already got a running setup, this shouldn't be an issue.  Check out
http://www.poweriseverything.com/impt-info/v-a-tablespage.html - this
will let you know what to plan for.

Hopefully I've been clear in my ramblings.  Feel free to fire back with
any questions.

73

Mike KW1ND