Ken Larson

typos happen

Guys, Thank You, Thank You. Chad, I'll replace the 6AWG to chassis ground with 2 AWG as you suggest. So, I think I am ready to go; just waiting for the panels to arrive and for the weather to warm up a little.

John T, thanks a lot for what you have been able to do.

Based upon the information both of you have provided I plan on making the following changes: I’ll use 8 AWG from the panels to the disconnect to the chrg/cntlr as it will be easier to work with. The Victron chrg/cntlr manual says to use 2 AWG, I tried larger size cables and the connections on the chrg/cntlr will accept a max of 2 AWG, larger will not fit. Therefore, I’m stuck with 2 AWG between the chrg/cntlr and the batteries. I’ll connect the positive output of the chrg/cntlr to a 12 Vdc 70-amp fuse (ANL type OK?) than on to the battery bank. The negative output will be connected directly to the battery bank. Then use 2/0 to parallel connect the batteries connecting the positive leg to a 300-amp fuse (ANL type OK?) to the positive input of the inverter. I’ll use 2/0 to connect directly to the negative side of the inverter. The WFCO 8955 has a built-in converter/charger (called the Main Board Assembly or MBA) to provide battery charging and supply the 12 Vdc to the power panel. All 12 Vdc devices get their power through the Power Panel and are fused in the power panel. To provide the charge current to the battery bank the TT manufacturer used 6 AWG wire with a 15-amp breaker. I disconnected the MBA from the 120 Vac bus in the power panel to prevent using battery power to charge the batteries via the inverter, want the solar to charge the battery bank. I than spliced a wire into the shore power positive leg prior to it being connected to the inverter. With no shore power provided the inverter auto switches to battery power, disconnecting from the shore power. This new leg was than connected to a newly installed standalone 15-amp circuit breaker to power the MBA only when connected to shore power. The 6 AWG that was originally used to provide charging power is now only used to provide 12Vdc to the power panel. The total amps used by the 12Vdc appliances is 105 based upon the 12Vdc fuses (7 circuits with 15amp fuses) in the power panel. Do you think I need a fuse in the 12Vdc leg from the battery bank to the power panel? If so, would a 12Vdc 150-amp circuit breaker be appropriate? The current set-up has been working fine, no problems. I can power all the 120 Vac appliances except the A/C and all 12 Vdc devices off the current battery bank. Based upon your advice it appears I need to increase the wire size from the chrg/cntlr to the battery bank to the inverter using 2/0 AWG wire due to the high current expected. Also, install the circuit breakers or fuses as you have suggested. Now, last issue: There is a 6 AWG wire from the power panel to the trailer frame and a 6 AWG wire from the battery bank to the frame for grounding. Should I replace those wires? The power panel lug might not take a larger wire is the only problem. Thanks again for all you advice in this DIY project.

Thanks to both of you for you insight, looks like I'm in for a major rewire of the trailer. Congratulations Chad. We celebrate our 53rd anniversary this year. Not bad considering I asked my wife to marry me on our first date and she said "yes".

Chad, I appreciate the extensive discussion you provided to my question. Now, I need a little advice on specifics. Like you our current travel trailer was an impulse buy but have grown to love it. The TT is a 25 foot that I have been modifying and upgrading ever since we bought it. The TT is the typical 30 amps. I immediately installed three Weize 100 ah SLA VRLA AGM batteries and an AIMs 2000 watt inverter. I replaced the shore power 10 AWG wiring with 8 AWG because of the distance from the shore power plug to the battey bank. Disconnected the WFCO converter and wired so it only comes on when on shore power as I did not want it running when on battery power. This system has worked well; we can run the microwave, TV, DVD player, A/C fan, coffee maker, toaster and Frig off the batteries along with my CPAP at night, I use a iPower portable generator (2000 watt start/1600 watt running) to recharge the batteries; but want to get away from the noise of the generator. Based upon my research and question answers I gotten over the last couple of days I have upgraded the solar system I want to install; I've attached an updated schematic of it. I believe I need to install additional circuit breakers but not sure just where and size; like in the 12 Vdc line from the batteries to the control panel and/or batteries to inverter. Would I need a circuit breaker between the shore power plug and the inverter or inverter to power panel? Also, as is shown on the schematic I thought I should use 6 AWG wire but an wondering if 8 AWG would be more appropriate? The run from the solar panels to the electronic "bay" is about 12.5 feet in cable length. The distance between components will be less than 3 feet as everything is close together, only have about a 3x3 foot space to install the new components. The ground wires are one from the control panel and one from the battery bank to chassi ground. Components: WFCO 8955 control panel, AIMs 2000 watt inverter, REC 330 watt solar panels (Vmpp=34.6, Impp=9.55, Voc=41.0, Isc=10.33, Pmax=-0.350C. Voc=-0.270C), batteries are Weize 100 ah SLA VRLA AGM's I would appreciate any council you care to share. Solar Schematic Updated.docx

John, thanks for the reply. My post really was to provide some information about battery charging and the things to think of regardless of the type of battery. Yes, the article was directed to flooded batteries but the concepts and considerations are the same.

I also made the choice today to upgrade the Victron 100/50 charge controller (700 watts max) to the Victron 150/70 (1000 watt max) which will allow me to add an additional panel (330 watt) should I want to in the future. Also, I ran across what appears to be a good explanation of calculating the charging parameters for a solar system. It can be found at: http://support.rollsbattery.com/support/solutions/articles/237882-calculating-proper-charge-settings-for-rolls-flooded-lead-acid-batteries

Thanks to all that have replied. As pointed out there are too many opinions on how to install solar correctly. I looked up Chads website and profile so feel I can rely on his council. Additionally, our trailer is small, 25 ft Dutchmen Kodiak (201QB) new last year. The system I started with was a kit from Northern Arizona Wind and Sun than I started modifying the parts to fit my perceived needs. I will be sticking with 12 volt as recommended. The batteries are Weize which from my reading reviews indicate that they are true deep cycle and have a good reputation; but again I'm relying on sites that I know little about. I was not able to find the Weize manufacturer site so had to rely on the reviews. In my limited knowledge and going with my gut feeling I settled on 6 AWG, which may be larger than I need, to reduce loss and less heat build up. Again, thanks for all your advice.

I've gone through everything I can find in this forum and other forums on solar on travel trailers. Head is swimming. Although we are seasoned RVs we have stayed mostly in RV parks over the years; however, now that we are retired and the travel budget is less we have decided to mostly boondock. We travel generally 7-9 months out of the year so we are almost full timers. I hate running our little generator (2000 watt) to charge the batteries so am going to solar. Need some advice on the switch over. Here is my situation: I have three 100ah SLA VRLA AGM Deep Cycle RV batteries wired in parallel in my battery bank, planning on two REC Alpha 340 watt panels or two REC N-Peak 330 watt panels depending on which I can get wired in series, Victron 100/50 charge controller, 250 volt circuit disconnect between the panels and charge controller, 100 volt 60 amp circuit breaker between the charge controller and battery bank, and 2000 watt pass through inverter. Currently I can run everything except the A/C, including the frig and microwave, off the battery bank for a couple of days before recharging. I'm also considering installing a SmartStartRV in the A/C unit. Now for my dilemma: Am I better off keeping the battery bank in parallel and 12 volts or rewire it in series to 36 volts? Some indicate that if I rewire than the bank will charge fast even under less than ideal sunlight. Also, if the batteries are wired in series and the inverter input is 12 volt will I damage the inverter? Some advice on installing the SmartStartRV in the A/C would also be appreciated, do you think I will be able to run the A/C after the SmartStartRV is installed? The A/C and microwave are pretty close in watts and amperage. Thanks in advance for any council you can provide. I've also attached a schematic of the planned system. Schematic of Solar Install.docx