Solar and generator

[dcwettstein]

I have 544 W on the roof putting out about 80 Volts max. I am in northern Wisconsin at a beautiful National Forest campground and It rained all day yesterday and cloudy today. At best I am generating 20-40 volts from Solar. That seams to help maintain my batteries only using min lights (LED) and furnace at night. Two days ago I had 87% battery and today its at 84%. I have not used the TV at all. What size Generator would be good to keep the batteries (4 golf cart 460 amp total) somewhat charged. I run the Refrigerator off of 12 V and also the water heater. I don't need the AC at all. What size and brand would be recommended. I am thinking of around 2000 -3000 Watts.

 

[sjandbj]

If your looking at just a back up when there is not enough sun then i would look at the Honda 2000. It is portable and takes very little space. Also if you need more power you can always bridge two of them together.

Regards,
Steve

 

[justafordguy]

I would go with a champion 3100 inverter type generator. It would also be able to run one a/c if needed.

 

[fredwrichardson]

I have 544 W on the roof putting out about 80 Volts max. I am in northern Wisconsin at a beautiful National Forest campground and It rained all day yesterday and cloudy today. At best I am generating 20-40 volts from Solar. That seams to help maintain my batteries only using min lights (LED) and furnace at night. Two days ago I had 87% battery and today its at 84%. I have not used the TV at all. What size Generator would be good to keep the batteries (4 golf cart 460 amp total) somewhat charged. I run the Refrigerator off of 12 V and also the water heater. I don't need the AC at all. What size and brand would be recommended. I am thinking of around 2000 -3000 Watts.

Most RV solar systems are 12 volts and are based on their battery bank. I would assume your system produces 12 volts so it can match your batteries. When you say volts I think you mean amps for that is what is needed to charge your batteries. A 500 watt panel produces an average of about 30 amps per peak sun hour, or about 150 amp-hours per day. The average RVers consume between 75 and 150 amp-hours of energy per day depending on their lifestyles. Unless you had no sun the system should keep your batteries fully charged. You would only need a small 1000 watt generator to charge the batteries if you are not going to use the AC. I agree with Steve in that the most practical generator and the one I would buy is the Honda 2000. Most bang for the buck and would be more than enough to charge batteries and run the RV in case of emergency.

 

[dcwettstein]

Yes my rig is 12 Volts, but, I get up to around 80 volts in full sun, into my MPPT controller. I only want to use the generator when the sun isn't an option like cloudy days and when camping in almost full shade.

 

[oscar]

Yes my rig is 12 Volts, but, I get up to around 80 volts in full sun, into my MPPT controller. I only want to use the generator when the sun isn't an option like cloudy days and when camping in almost full shade.

Are you sure? All the solar systems I have installed ran around 19 volts max, the regulator taking it down to the 13.6-14.2 needed for charging depending on battery type. I suspect you're getting 80 watts, much more and it wouldn't fit up there. Even 80 amps doesn't make sense, as it would be 12x80=960 watts which, again, takes up a lot of real estate.

Second the Honda 2000 EU. It's extremely fuel efficient and quiet. It also has an eco setting, which adjusts RPM to the demand. So, when the initial bulk charge starts slowing down the RPM's and with it the fuel consumption and noise go way down. 56dB at 10 feet is more than acceptable during the day, especially if you aim the exhaust away from the seating area.

What I do recommend is that you get a quality battery charger, that has enough oomph, AND a smart regulator. Max oomph is about 15% of the Ah capacity of the bank, and the smart regulator should do three stage charging adjustable for specific battery types. (Lead acid/AGM/Gel) including an equalizing cycle for lead acid batteries.

 

[Imurphy]

Plenty of panels will do 30+ volts. If you wire them in series it ups the volts even more. Good thing about using higher voltage panels is that even in cloudy weather you still get decent power. The use of an MPPT controller is required. I am a huge fan of PWM controllers, but you can not use high voltage panels with low voltage systems.
Nothing out of the norm there.

I carry a Honda 2000. It is a great generator, quiet and fuel efficient. When my system is running low and the forcast is not promising. I bring it out. connect it to the coach using a 50 to 30 amp adapter. And let the magnum do its thing. Leaving it on "eco" it will run up about 60% speed while the magnum pushes out 60+ amps. as the magnum cuts back so does the honda. Usually after about 3 hours I am up to 80% SOC and turn it off. Some times I will leave it run for a bit just cause, but thats all selective.

It will be a waste of fuel to run a generator and use your stock "converter" to charge the battery bank. You really need to use a good battery charger to take advantage of the generator running. not to mention actually charge your bank.

 

[dcwettstein]

Thanks all. I purchased a Honda 2000 and it seems to work good. I have 4 Unisolar peel and stick panels that are 136 watts each and put out 46 volts each. I have two in series and the two pairs hooked in parallel to give me a max of 92 volts which I never see. Normally my voltage reads between 70 and 80 volts. With the higher voltage I could use lighter gauge wire (10 Gauge)coming from the roof with little voltage drop. The MPPT controller gives the battery the required voltage and will give the batteries more amps, due to the higher voltage, for faster charging.