RV NET solar install?
Ricently purchased a new to us 07 Discovery with a full slide. Looking to full time in the NEAR future. Would like to start planning my solar install. I have a large 8x9 foof area over the bedroom th...
Forum Discussion
red31 wrote:
batteries need a bath!
Not if they are AGM. Mine are clean, no deposits of corrosive fumes outside. I am even considering placing them into the same storage closet with controller.
As noted, the proximity of controller to battery is important. With 750W solar I would try and run cable as thick as AWG 4 from controller to battery. With controller placed within 10ft one-way run from battery, AWG 6 would still work though.
Here is Voltage Drop Calculator. Enter: Phase= single, Voltage= 13.5, Max voltage drop= 2.2, Length of cable= 10, Current at the end= 50.
The goal is to keep Voltage Drop under 3%. You might see the recommendations to keep it lower yet, under 2%.
With voltage sense wire (I think Morningstar has it listed as an option), the controller will "know" about the voltage drop and will adjust the voltage accordingly, so it doesn't matter much, whether Voltage drop is 1% or 3%.
With 3% Voltage drop you will be losing 3% of your PEAK harvested solar power, i.e. less than 3% total. This is less than 6 AH from 200 AH daily. The only drawback that I can see with a very long cable with a very high Voltage drop is that you will have to connect your inverter directly to the battery terminals, otherwise if connected closer to controller, inverter will be getting too high voltage. And some other DC devices that are not wired directly to battery terminals, might not like a voltage too high. So it's better to keep V-drop under 3%.
Yes, controller generates heat - why else it would need that monstrous heat sink? So the closet should better be roomy.
Yes, TS 45 and TS 60 have a remote display, optional for extra $$. You won't be needing it much. My controller came with a built-in display, and because I only need it when adjusting some parameters of controller, which doesn't happen too often, - I didn't bother with a remote display. Didn't bother with Trimetric either - controller reports that it's keeping batteries full 9 days out of 10, so Trimetric wouldn't tell me anything important.
