In 2012, I installed two new 8D house batteries before we hit road starting our full time RV adventure.
In 2016, I added 500 watts of solar panels to the roof of the RV. We enjoy boondocking and solar panels are a logical solution to supplement our power usage needs. Click to read about my solar installation.
With this setup, we only needed to run the generator in the morning for making coffee and to give the batteries a boost (manufacture suggested) and while watching tv for an hour or so in the evening, providing we have good sun. If we weren’t using the computer, the house inverter, and my power tools for my rock hobby, we could go several days without running the generator.
While boondocking in Quartzsite, Arizona, in January 2019, I noticed that the generator was running almost continuously. What could be going on?
After some investigation, I found that the batteries were damaged during a two-month storage period (November through December 2018) when we were doing some non-RV travel. We had left the coach in sunny Arizona, in an area where it generally doesn’t get too cold or snow. It was a a freak winter in Arizona and it got cloudy, cold, and had lingering snow. 
As full time RV folks, we don’t really ever shut the coach down completely. I had programed the generator to start when the batteries dropped to 11.5 volts and cycle off when the batteries were 90 percent charged.
Before we had solar panels, I would set the generator to charge the batteries until they reached float stage.
My thought was to balance generator runtime against the energy the solar panels would create to fully charge the batteries, hoping to not run the coach out of diesel trying to keep the batteries full.
As the power level of the batteries dropped, probably due to the heat running to keep the RV from freezing inside, the generator would run for a short amount of time, charging the batteries to 90 percent capacity, and then cycle off. With the solar panels covered in snow they were not doing their part to finish charging the batteries to full. Had I set the generator to run until the batteries reached float stage I would have been fine.
With the batteries damaged (they were actually bulging in places) I needed to find replacements. The battery bay of our Country Coach Allure is big enough to accommodate more than the engine battery and the two 8D house batteries that provide us with 490 amp hours. I wanted to double our amp hours if I could.
I began searching for batteries in a configuration that would give me my extra amp hours but not empty my wallet in the process. I looked at golf kart batteries, various AGM type batteries, and lithium. Lithium were cost prohibitive for us with a 200 amp hour battery cost close to $1000. I did not want to deal with monitoring acid and water levels of the 6 volt golf cart batteries, so I scratched them off the list. I decided to go with the sealed 8D batteries again. The cost would be less than the lithium and more than the golf kart batteries.
We moved into the Atlanta, Georgia area for my work and I was hopeful that I could find the batteries we needed at a decent price. It was my lucky day. I found a battery outlet (through Facebook) that sold UNUSED, one-year-old batteries. These batteries were kept at cell towers as back ups to the batteries currently being used in the UPS (uninterruptable power supply) in case failed. The batteries are replaced every year whether they are used or not.
They are AGM PowerSafe SBS 190F sealed batteries providing 180 amp hours each. The retail price for these batteries when they are new is in the $700 range. This outlet was offering them for $200 each. I bought four, and they gave me $50 for each of my old 8Ds.
Before I get into the installation of these batteries, lets review the particulars. What we HAD was two 8D sealed batteries, L 20.47 x W 10.64” x H 9.08”, weighing 161 pounds each, providing a total of 490 amp hours, at a cost of $1600 in 2012. We NOW have four SBS 190F sealed batteries, L 22.10” x W 4.90” x H 12.40”, weighing 123 pounds each, providing a total of 720 amp hours for which I paid $800. So the net is a cost of $800 LESS than my last battery purchase, a GAIN of 230 amp hours, and an INCREASE in weight of 170 pounds. (Just need to get rid of some rocks now!)
Because I was going from two batteries to four, I needed to make some adjustments to the wiring. I’m an electrician so this is not out of my knowledge base. Here is the wiring diagram for my setup.
The batteries came with tabs, circled green in the picture, for connecting the batteries at the ends. I needed them to connect on the top so I removed them.
Here is a close up of my final wiring setup.
The 190Fs are longer than the 8Ds and did not fit in the battery tray. They sit up on the back of the tray and I installed a strap around them to keep them from moving.
So far we are very happy with the performance of the batteries. We are back to only having to run the generator in the morning to make coffee and give the batteries a boost and to watch TV in the evening. I’m cutting and polishing rocks during the day, my wife is happily working on her computer, and my diesel level is high. Life is good.
