Charging the batteries

Be warned, this post is a bit heavy on technical issues and one image.

Life in a trailer, especially boondocking, requires monitoring your battery capacity and usage. The first thing I did to help this when we had our ’92 25′ was get some Sears AGM batteries. This gave me a larger capacity and less worry about them. Changing both trailers to LED lighting helped a lot more. We purchased a couple of generators to help with charging when we needed it and ostensibly run the air conditioners with two of them running. I also purchased a set of portable solar panels. I had all the pieces lined up for extended battery usage, except one. Solar on the trailer.

This was accomplished early this year, shortly before we started our fulltiming/CalExit. In our travels since May (2017) the solar panels have performed fantastically! But events during our travels have made me rethink my charging methodology.

Before solar, there were two methods of charging. When we were hooked into shore power, the converter/charger will charge the batteries and provide 12v DC power. When towing, the tow vehicle will provide a small amount of charge through the 7pin umbilical cord. I remember my father hooking up our station wagon to the trailer and letting it idle for extended periods to give the trailer a charge while boondocking. I have not tried this method.

The converter/charger that came with the trailer was a single-stage charger, meaning it was either charging or not. On or off. This can wreak havoc with your batteries, especially if you leave it plugged in while ‘stored’, as we did. I replaced the converter/charger with a multi-stage version. This flavor will do a heavy, high amperage charge until the batteries reach a certain voltage. The next stage is a consistent, lower amperage charge until a different voltage setpoint is reached. The final stage is a trickle charge just to keep a preset voltage level.

The one issue/problem when adding a solar system, and its inherent charge controller, is to ensure that the two charging ‘brains’ don’t conflict with each other. Luckily the solar charge controller is adjustable in what voltage it shuts off at. This way I was able to research the voltage level for the shore power converter/charger and adjust the solar charge controller to just below that voltage. That way, if we were on shore power the 110V converter/charger would do its’ high amperage charge and get it to a voltage higher than the solar chargers threshold and the solar charging would be negated.

What change have I made in charging the batteries? Let’s lay a bit more groundwork first.

I no longer have 2 generators, I never did use 2 to run the air conditioner which made the 2nd one expendable. After our 4+ months on the road I never used our portable solar panels, therefore they are for sale (contact me for more info). We are now down to shore power charging, solar charging and generator charge (which is essentially shore power charging since the generator creates 110V AC).

The months on the road brought up some odd issues that have steered me to my new path. We had problems with our refrigerator when we started that were hard to diagnose and explain. It was not working when we left and started working mysteriously after we were in Arizona for a few days. It got weird again in Texas. When talking to the repair shop they mentioned that irregular 12V power has been seen to cause problems with refrigerator circuit boards. I changed the shore power cables and it started working just fine, making me think it was the cables, but maybe it wasn’t?

We did great on power for about another month until we were in Williamsburg VA. The spot for the trailer there was very shady and I noticed that the battery was down to about 82% capacity and the shore power was charging it slowly, if at all. I immediately thought it was the shore power converter/charger and ordered a replacement. Once it was swapped out, charging was back to normal.

That got me to thinking that maybe our refrigerator problems earlier were symptomatic of a failing converter/charger. I am now fairly convinced that is true as the refrigerator has not exhibited any type of issues, even when the internal fins were coated with ice due to humidity.

When we were in New York and taking advantage of some courtesy parking, we had some issues with the 15amp shore power that was provided. The electrical management system that I installed, before we left, would disconnect our power and reconnect continuously. It made the power connection unusable so we relied upon the solar to take care of the batteries. This allowed me to notice another aspect of the shore power converter/charger. When it is in its’ first stage of charging it uses a LOT of amps! I saw about 18 amps at one time! That was overloading our 15amp connection.

My next thinking was if I could turn off the shore power converter/charger, I could then control when I used it and turn it off when we are on 15amp. One option is to turn off the breaker but that would also make the inverter inoperative. I didn’t want that. I made my own solution. I got some parts at Lowes and created a device that the converter/charger plugs into and then it plugs into the wall. It contains a switch that I can easily turn on and off.

This relates to an ability for me to disable the shore power converter/charger when on a minimal power connection and allow the solar panels to exclusively charge the batteries.

The empirical proof is in. For the last three weeks, we have been on 15amp power, with the shore power converter/charger turned off, and we have full battery power going into each evening. I feel it is a great success.

Various enhancements

As launch date counts down and the solar project is done, there are numerous other little things that I can work on now. We have about 2 weeks to get all this done and time is running out. Here are some of the things that have been done.

Stove guard

The small little piece of aluminum that Airstream stuck to the wall next to stove was for some protection but it slipped over time and was more unusable.

We also needed more space for stuff. I got a piece of stainless steel and attached it to the wall:

We plan to put spice containers (magnetic backed) on there and a magnetic knife rack:


Bedroom lights

The trailer came with two lights on each side of the bed. One directional and one a sconce on the side. These were nice lights but we always seemed to hit our heads or arms on them.

We liked the direction lights but not the sconces so much. I was able to find some flush mounted lights that did both white and red light! I love a red light at night. I removed the sconces, put the flush mount ones where the directionals are and moved the directionals. Like this:

Another mod that needed to be done was using the old holes for the sconces. We put small baskets in the mounting holes. The power cable hole will have a phone charger cord going through it. That way we have a location for our phones that is easily accessible:


Underbed storage

The trailer bed will lift up and grant you access to the drawers that are there. You can also access some of the rear storage in that manner. We thought it would be nice to have a bit more storage available underneath. I took a piece of plywood and made a divider wall to cordon off some extra space under there. Space I wasn’t using from behind:


Key hooks

I have a habit of putting my keys, wallet, sunglasses on any flat surface that is near a door. This will be a problem in the limited confines of the trailer. We got a small set of hooks and are looking for a basket to hang by the front door for me to use. Here is the hook set (with a set of keys on it!):



I have looked at Centramatic wheel balancers for quite a while. I wanted to get them when I got my new tires and wheels but wasn’t able to until now. We only have 3400 miles on the new tires so I don’t feel that bad about the delay.

These devices are automatic wheel balancers. These are rings that attach to your wheel that have a weighted ballast in a viscous fluid. As speeds go above 35mph the ballast will move to a location opposite where your wheel/tire has extra weight, balancing it on the fly. This video can explain it.

This requires removing and reinstalling ALL 4 wheels! Not a great job but it needs to be done. Time to use the trusty trailer aid.

Simply take off the wheel and put on the centramatic:

The instructions state that if your wheels have been balanced recently to NOT remove the weights. I considered 3400 miles to not be recently so I removed the weights:

Put the wheels back on and torque them to 110ft/lbs.


Inline Surge Protector

I have two surge protectors (30a and 50a) that I try to use whenever I hook up to shore power. Better safe that sorry. However, this can be inconvenient and easy to forget them. I recently saw something about an inline version by Progressive Industries. I got one and just installed it.

There appeared to be room by our fuse panel above the bed ( the same picture as above but it shows it):

Disconnect all the power, remove the shore power wire from the panel, put the shore panel wire into the surge protector, run another wire from the surge protector into the panel. Done! Just like that, easy, no problem. Right. Anyone that has worked on any project knows that things are not that simple.

The panel after the front cover is off. Take out that red, black, white and ground wire. Remember these are 6ga wires and are not real flexible. THEN I had to put another set of 6ga wires back in and connect them. Lots of vise grips twisting and cramps in the hands.

I was able to move the panel up higher to leave room for the surge protectors. Here it is all wired up:

I also made a video to show it and the monitor display that you can get. I made a mistake in the description, it is a Progressive Industries unit, not a Progressive Dynamics.

I still have a few more projects to finish so I will post another entry.