Long Term Storage for RV Solar Power Systems

RV Solar Power System Maintenance

RV Maintenance - What an oxymoron.  Recreational Vehicles are for recreating, not something to be constantly working on.  Put those tools down and go relax!  But even while driving a car you have to pay attention to your gasoline levels, and that’s a form of vehicle maintenance.  So, by definition, everyone performs some kind of service on their primary vehicle fairly regularly. 

What about an RV?  Well, that will vary from rig to rig.  But solar charged batteries on an RV require some extra care.  Here are some maintenance suggestions along with the minimum frequency these “services” require.  After reading, see how you can fit these basic chores into your RVing lifestyle.

FYI - Calling for a tow when you’re stuck out in the woods, is also not RVing…

There are the three categories or pieces of an RV’s Solar System that may require maintenance:
Solar Panels (either mounted on the roof or portable)
Solar Charge Controller System (and the remote if installed)
Battery Bank (Flooded, AGM, GEL, or Lithium)

(Fuses and potential wire connection oxidation are also areas to check, but these items are included in one or more of the three solar categories listed above.)

Solar Panels -  Clean the solar panels as desired for optimum performance. After a hard rain, clean them. After a drive through dust or dirt, clean them. Sitting in a dry nearly wind free area - they can still get dirty from birds, plants, trees, and flowers that secrete sticky goo - clean them using water or 92% alcohol or a combination.  Infrequent cleanings won't harm the panels, but performance will suffer if dust or other debris is preventing photons from reaching silicon cells.

WARNING: Solar Panel Glass has an Anti-Reflective coating - abrasive cleaners may damage this surface.

Solar-Panels

The easiest way to check the cleanliness of your solar panels is to read your solar charge monitor and take note of any steady decline in solar electric input. Sometime during the first two days after setting up a long term camp, write down your solar activity at morning, noon and pre-dusk.  Then in a week or so, write these numbers again, comparing them to your initial readings. Keep comparing every week or so.  When the performance decreases, clean the panels and start your list all over.  

A leaf or a bird mess will create a very noticeable reduction in solar panel output.

Charge-Controller

Solar Charge Controllers require little in the way of actual elbow grease, but it is a good idea to keep an eye on them.  Every week or so (weave this into your schedule so you can officially avoid a worse chore) grab the big wires going in and out of the charge controller(s) and make sure they are tight - easy here, don’t pull anything loose.  Do not tolerate loose connections.  Either tighten them or get them tightened.  If/When you find a loose connection, fix it then make a note of it or take a picture and monitor it closely during the next couple of inspection cycles.  If the connection stays tight, good.  If it continues to loosen, then have this item inspected by a professional.  

As for corrosion, that can be an even bigger problem.  White powder on any electrical connection is cause for concern.  That powdery substance is oxidation (in iron this is called rust). This powder indicates a poor connection or a failing component in the wire run.  Once again, seek professional assistance to locate and correct this situation quickly.  Near batteries, the powder could have shades of green or blue mixed in. This is usually the remnants of evaporated battery acid.

Battery acid is a mixture of water, sulfur, and some other compounds that should be avoided.

AM Solar Lithium Battery System and Lifeline starter battery

AM Solar Lithium Battery System and Lifeline starter battery

Battery Bank Inspections come in three varieties based on which of the three types of batteries being inspected.  Flooded batteries have liquid acid sloshing around - but they can be re-filled.  GEL / AGM Batteries have their acid stabilized (it won't slosh) but can’t be re-filled.  Lithium batteries have a paste-like substance that absolutely cannot be re-filled.  Inspecting batteries is pretty straightforward and all battery types have some checks in common.

Check for loose cables.  Check for corrosion (powder).  Lastly, and only with flooded batteries, check the water level. Never overfill flooded batteries and always keep the cell water levels equal.  Never let the top of the material in the cell get dry (the finned “stuff” is called the plates and that's where the reaction takes place).

Storing a solar equipped RV for long periods of time, a month or more, can cause issues, most common among these is battery damage.  Here are three common types of RV storage and what you should do to protect your equipment:

A)   Park it outdoors

  • Log all issues found or fixed before you store your solar equipped RV and write them down.
  • Turn off all the loads that can be turned off.  This includes DC loads coming directly from the battery and AC loads using the inverter or shore power.
  • Leave solar and house battery charge circuit ON and walk away.  A well designed/matched Solar System should be able to keep the batteries in operational condition so long as there are no loads left on. Loads could cause the batteries to be drawn down below the capability of your solar system.
  • If using lithium batteries, turn OFF the Lithium Master Disconnect switch to prevent current from entering or leaving the lithium battery bank.

B)   Park it inside (like a Storage Facility or Garage) and walk away

  • This is a bad idea for lead-acid, flooded, GEL or AGM batteries.  These batteries must be kept charged.  Only lithium batteries can be left for extended periods of time without being charged.
  • Log all issues found or fixed before you store your solar equipped RV and write them down.
  • Turn off all the loads that can be turned off.  This includes DC loads coming directly from the battery and AC loads using the inverter or shore power.
  • Turn OFF the Lithium Master Disconnect switch to prevent current from entering or leaving the lithium battery bank.

C)   Park it at a Fully Staffed Storage Facility where your rig will be monitored

  • Log all issues found or fixed before you store your solar equipped RV and write them down.
  • Turn off all the loads that can be turned off.  This includes DC loads coming directly from the battery and AC loads using the inverter or shore power.
  • All Flooded Lead-Acid Batteries including GEL and AGM, must have a continual “trickle” charge (about 5% of the battery’s amp hour rating) when stored (a 100 Ah Battery needs a 5A DC trickle charge). If these battery types are left unplugged and unattended, their natural, internal, self-discharge will ruin them in a matter of weeks.
  • If using lithium batteries, turn OFF the Lithium Master Disconnect switch to prevent current from entering or leaving the lithium battery bank.  Some of our clients have had their batteries ruined while in storage at a facility with a trickle charge system because the power was accidentally disconnected by someone tripping over a cable or an outage caused by a lightning storm.  Lithium batteries are expensive, don't take any chances by storing them ON.

Note: Lithium batteries have almost no internal drain.  Therefore, after turning the battery master switch to Off, they can sit for up to a year without any charge source, yet will remain fully serviceable.

(Keep in mind that this article only covers RV Solar Systems. Other components and areas of your RV may need additional or even specialized treatments.)