Community Forums

Chuck Q · 12-26-2017, 11:50 AM

I have 375 watts on the roof with a Go power 30 amp controller. Just purchased a portable 120 watt system to charge my boat motor battery. Can I also use this on the MH to parallel charge the house batteries?? It does have a cheap controller that I will replace.

Tony Lee · 12-26-2017, 04:59 PM

Quote:

Originally Posted by Chuck Q

I have 375 watts on the roof with a Go power 30 amp controller. Just purchased a portable 120 watt system to charge my boat motor battery. Can I also use this on the MH to parallel charge the house batteries?? It does have a cheap controller that I will replace.

Yes, can just hook it up direct to the battery via the regulator that comes with it - but you might find that if the wire gauge is too small, there may be little current or none at all supplied from the portable unit. Can help overcome this by having the regulator as close to the battery as possible, OR if your battery is always in need of extra charge, you can actually hook the panel direct to the battery and just keep an eye on the battery voltage and disconnect it if the battery voltage rises above its normal end of charge voltage (14.4 or close). Another possibility if the gopower controller has the output current limited rather than having a limit on how much panel power can be connected, then since the existing 375 watts of panels is rarely going to give you anywhere near 30 amps into the controller, you might be able to hook the extra panel in parallel with the existing panels. Option 1 is probably the easiest and safest.

Soppy · 12-26-2017, 05:32 PM

Quote:

Originally Posted by Tony Lee

Yes, can just hook it up direct to the battery via the regulator that comes with it - but you might find that if the wire gauge is too small, there may be little current or none at all supplied from the portable unit. Can help overcome this by having the regulator as close to the battery as possible, OR if your battery is always in need of extra charge, you can actually hook the panel direct to the battery and just keep an eye on the battery voltage and disconnect it if the battery voltage rises above its normal end of charge voltage (14.4 or close). Another possibility if the gopower controller has the output current limited rather than having a limit on how much panel power can be connected, then since the existing 375 watts of panels is rarely going to give you anywhere near 30 amps into the controller, you might be able to hook the extra panel in parallel with the existing panels. Option 1 is probably the easiest and safest.

X2 Any of the above will work just fine.

vsheetz · 12-26-2017, 06:36 PM

Your controller should be able to handle the additional capacity.

I have roof and portable panels on the current (MPPT controller) and previous coach (PWM controller). Current coach the portable panels are wired as an additional string into the combined box. Previous coach all panels were wired in parallel - with the portable simply connected to the controller input in parallel to the roof panels.

okmunky · 12-26-2017, 07:54 PM

I added an additional 100 watt panel to my existing 272. Mine is tied into the combiner box so it uses my 20 amp charge controller along with the rooftop panels. It made a huge difference because I can tilt the new panel to maximize the charging.