solar panel installation advice needed - Maxum Boat Owners Club

timer · 07-27-2013, 12:17 PM

The other day i purchased a 30 w solar panel & controller. Im pretty sure its too small for a 3000 scr but it should help alot. We go to alot of islands & spend a day or so & many islands generators are not allowed. I purchased the 30 w instead of larger due to protablility as i dont want to bolt the thing on the boat. I simply want to store it in the cabin & when im at a dock on an island i can pull it out & put it on the dash. Question is the controller. The solar panel recommends the use of one. Is it really needed? THe controller mentions mount in a ventelated area. Hmmm. I want to mount it in the cabinet where the batttery switches are (beside the wet bar in the cockpit). hoping thats ok. This also allows the controller to be close to the batteries. Also wondering about hooking the controller to the battery house switch (#2) vrs the battery itself. Reason is if the boat is at an island & im on board the battery switch is always at #2 but if the boat is home & not in use the switch will be at off & the panel will be in storage. Will these controllers draw power out of a battery ?? the battery switch should protect that if that is the case. I do plan to run wires back down into the engine compartment , across & back up into the helm. I want to put a plug in for the panel in the area by the drivers right knee( where the macerator controls & 12 receptacle are) lastly, old solar panels i have owned say to make sure disconnected prior to running a motor. Is this still the case?
thanks guys
Timer

shrew · 07-29-2013, 03:07 PM

I beleive that part of the function of the controller is to disipate energy when not being consumed. If there is no draw on the system (batteries are full and there are no 12v devices) then something needs to be done with the excess energy. There is such a thing as OVERsizing your solar system, though it is rare to accomplish such a task. The controller needs to send that energy somewhere. It does so by generating HEAT. This is why it would need to be well ventilated. With a 30 watt solar panel, you'r generating about 1.8 amps under perfect conditions. I'd expect more like 1amp/hour if mounted flat (not oriented toward the sun and not high noon). I'm not sure if this will be an issue for you or not.

mmwjr · 07-29-2013, 05:23 PM

shrew is correct. While it's unlikely that you'll achieve max changing if the batteries do become fully charge they will start overcharging which will boil the electrolyte which will evaporte away in a vented battery or build pressure in a sealed battery that may cause it to rupture.

So as Dirty Harry says; Do you feel lucky?

IMHO install a controller

timer · 08-01-2013, 11:42 PM

That all makes sence. I have done some research in the mean time as well & im thinking the best place for the controller for ventalation is the engine compartment & its close to the batteries. My original plan was the small cuppboard where the battery switches are. Maybe not so good.
Thanks
Timer

mmwjr · 08-02-2013, 01:14 AM

If the engine compartment make sure the controller is rated for that location,i.e. spark arrested.

timer · 08-02-2013, 02:26 AM

You make a very good point
Ill check
Thanks
Timer

OceanStateTuning · 08-04-2013, 03:54 PM

Too much moisture in the 3000scr's engine compartment for something not marine rated IMO

vffb507 · 08-09-2013, 06:39 PM

The "controller" is for controlling the generated electricity for charging batteries. A very good idea to prevent, as was said, over charge. Just to clear a couple misnomers... Use of a solar panel alone to power something does not necessarilly need a charge controller. Also if said panel is left in sun and not even connected it will be fine. It will have a zero current (no amperage) open circuit at the connections, it does not "need" somewhere for the electricity to go, it just won't have the "flow" or current to do anything until loaded.
The controller needs to be in ventiliated area just to ensure it has fresh air for self cooling. I wouldn't mount in engine area unless it is rated "intrinsically safe" (ie okay for explosive atmospheres) and if damp a good point for marine type too. If you can mount it where it will have airflow around itslef to cool it would be fine.

timer · 08-10-2013, 02:13 AM

Thanks vffb507 & ocean state tuning
I have not done anything yet as i have been on another short trip. I have pretty much decided to mount the controller in the cabinet in the cockpit where the battery switches are. Like i think i said. I will only be plugging in the solar panel ( putting on the dash) while at an Island for an extended period of time (a day or 2.) Im pretty sure this wil not be sufficient to keep up with the draw from the fridge but im hoping it will make a noticable difference in extending battery life.
Timer