Need help determining voltage of existing system on boat

I recently purchased a sailboat with an existing solar charging system for the house bank. I am planning to upgrade to a 48v system with new panels but I might try to include some of my existing panels. They are mounted on the roof and would need to be removed to examine the underside but I don’t see any markings topside that indicate whether they are 12v or 24v. My controller is a RV power products solar boost 50 12/24. Any ideas on how to determine voltage? Thanks for any input.

your asking about panels? I think your going to have to remove one.

teecomp said:

I recently purchased a sailboat with an existing solar charging system for the house bank. I am planning to upgrade to a 48v system with new panels but I might try to include some of my existing panels. They are mounted on the roof and would need to be removed to examine the underside but I don’t see any markings topside that indicate whether they are 12v or 24v. My controller is a RV power products solar boost 50 12/24. Any ideas on how to determine voltage? Thanks for any input.

Click to expand...

Your 50A SCC voltage of either 12V or 24V is the battery voltage Not the panel voltage which is irrelevant.
So what voltage is Your battery?
What is the max input volts of the SCC?

Look at the label on the underside of the panel for.
Watts
Voc
Vmp
Imp
Isc

teecomp said:

I recently purchased a sailboat with an existing solar charging system for the house bank. I am planning to upgrade to a 48v system with new panels but I might try to include some of my existing panels. They are mounted on the roof and would need to be removed to examine the underside but I don’t see any markings topside that indicate whether they are 12v or 24v. My controller is a RV power products solar boost 50 12/24. Any ideas on how to determine voltage? Thanks for any input.

Click to expand...

I’d measure the input, open circuit panel voltage to the SCC ( very carefully) on a bright day. Then I’d stick my nose under the panels and try to guess their wiring - series, parallel, some combination. And divide VOC by series count.
Or if you really can’t see the wiring, use a few typical VOC numbers of regular panels and see which might divide out sorta close to a plausible arrangement of your panels.
If it is safer, then measuring volts into SCC while connected and assuming they are operating at their MPP should also work.

Measure incoming voltage at PV- / PV+ just before charging begins in the morning, and during maximum output during bulk charging.

teecomp said:

I recently purchased a sailboat with an existing solar charging system for the house bank. I am planning to upgrade to a 48v system with new panels but I might try to include some of my existing panels. They are mounted on the roof and would need to be removed to examine the underside but I don’t see any markings topside that indicate whether they are 12v or 24v. My controller is a RV power products solar boost 50 12/24. Any ideas on how to determine voltage? Thanks for any input.

Click to expand...

I like this video a lot, helped me when designing my system.