Hi all,

Someone on another forum pointed out to me a negative of putting panels in series.

Here is the sad news.

if one panel is shaded and only putting out 4 amps–and the other is in the sun and putting out 7 amps–the total output will be limited to 4 amps. The voltage will still be doubled.

This works as an argument for using 12 volt batteries in parallel rather than 6 volt batteries in series.

Hi all,

My first night boondocking with no shore power in the Kustom Koach.

I left the fridge on 110 volt, but turned *off* the water heater. I left my laptop computer on.

By 6 a.m. the batteries were at 12.1 volts–so I shut off the fridge. This fits with 400 watts per hour for 10 hours–or about 50% of the capacity of the battery bank.

The Kustom Koach, with outdoor temperature at 6 C out doors appears to loose heat at about 1 degree per hour.

Tonight, if I can get the batteries back up to full charge, I'll close the door to the bedroom, turn *off* the fridge and use my smallest heater.

It is 7:45 a.m.–and the solar panels just kicked in! Only 0.1 amp, so far–but it boosted the battery voltage to 12.2

Hi all,

Well my first boondocking trip is over. I had a 15 amp circuit on three nights, and survived on battery power the other 3 nights.

On the 2nd night without power I used very little power–only the 12 volt heating blanket. I also turned off the fridge and kept my food cool by using 2 freeze packs that I normally carry.

That and a few parasitic loads dropped battery voltage from 12.6 down to 12.4 by morning. I chose to run my laptop on it's own batteries.

In the morning I cooked my breakfast (bacon strips) in the microwave, and made toast in my electric toaster (800 watt unit).

I did forget to turn on the electric water heater. I did run the fridge on 110 volt as I drove–and refroze the freezer packs. In the afternoon the temperature started to rise–so I went back and cut in the roof air conditioner–running it while I drove.

The 3rd night it was much warmer–so I used my fantastic fan for a couple of hours to cool down the RV. As I was in USA I did not access the net via my usb modem–but rather played back an audio book I had downloaded previously (using the laptop batteries). Battery voltage started at 12.6 and by morning was 12.5 volts.

It seems my Dometic fridge requires more freeze packs than my ancient Norcold (in my previous RV) in spite of having significantly less storage. I have them–but just didn't bring them along.

Hi all,

I just spent my first night boondocking in cool weather in my RV.

It is equipped with 875 amp-hours of battery storage (Walmart 12 volt deep cycle batteries @ $0.60 cents per amp-hour)–and they were at 100% state of charge.

I decided to see if I could use the batteries to keep warm.

The low temperature for the night was 6 C (42 F), so there was no risk of freezing damage. Just to make sure I set the air conditioner "heat strip" to cut in at 5 C. (40 F)

My RV has a sliding cloth "door" for the bedroom. I shut it to reduce the area to be heated. I also put a "vent pillow" both the vents. I fully closed one window blind–but left the other 1/2 open.

I connected a 466 watt oil filled heater and set it to keep the bedroom at 18 C (64 F).

My batteries lasted the entire night and did not go below 50% state of charge (12.1 volts)–and the kitchen area got to 12.8 C (55 F) so the heat strip did not "add to the load". I have a kill-o-watt meter–and I clean forgot to put it "in the circuit".

Today I drove for about 3 hours. It was a dull day so the best my solar system did was about 5 amps of output. The solar panels returned about 40 amp-hours in total. I run my fridge on 110 volt when I trundle down the road, and recharged my laptop batteries. I also ran the fridge for one hour while the RV was parked (motor *not* running, of course). The "house" batteries got to about 12.5 volts (measured "under load" at a C40 rate) This represents about 90% of fully charged.

Hi all,

I wanted to test what happens to my batteries. The chemical reaction in lead acid cells is endothermic–but the batteries do have resistance. At some level of "demand" the scales tip–and the batteries begin to heat up.

The system consists of seven 125 amp hour Walmart batteries from Johnson Controls. They do not have a "cold cranking amps" rating. No solar charging was being done–panels covered in snow. The inverter is a Cobra 2550 (2500 watts, 5000 surge).

I have placed a minimum maximum thermometer on top of the four battery bank, and I'll be running the inverter from both banks. Voltages are measured by the reading on the 3024di Blue Sky controller, and by a cigarette lighter voltmeter unit plugged into the TV power outlet.

Battery banks at 12.7 volts at rest
Battery banks at 12.5 volts when inverter turned on
Battery banks at 12.3 volts with 60 amp load from block heater (584 watts).

Friday Dec 18 at 10:40 am temperature -14.2 C outside and battery bank at -14.2

Battery banks at 11.9 volts under 60 amp load
Battery banks at 12.2 volts no load (inverter turned off)

Friday Dec 18 at 11:10 am temperature at -13.6 C outside and battery bank at -13.6

Battery banks at 11.8 volts under 60 amp load
Battery banks at 12.2 volts no load (inverter turned off)

I will be going back in three hours and checking the no load voltage.

Friday Dec 18 at 2:00 pm battery banks at 12.5 volts.

Conclusions so far:

875 amp-hours with a load of 60 amps produced no measurable temperature rise in the battery box. Load per battery is ~8.6 amps.

Even a small load such as 8.6 amps per battery for two hours shows a rise in voltage if the batteries are allowed to rest for some time.

Hi Deidra,

As I only have the Uni-solar I'm not in a position to make a comparison. It is almost a moot point as the US 64 panel has been replaced with something else which has a greater output–and has no metal frame.

I like the idea of no glass, and no frame either.