Forum Discussion

Darklock's avatar
Darklock
Explorer
Nov 02, 2021

best method for maintaining batteries

I just got a new house battery, (flooded wet cell)to replace the old tired one. I want to get the most life out of it. What is best for keeping it maintained while sitting for extended periods? I have 200 watts of solar (two Renogy panels and their controller). Is it best to just keep it hooked up and let the panels and controller do their thing, or would I be better off disconnecting the battery and using some sort of battery maintainer/smart charger?
  • I have 4-6v batteries and just let my solar maintain them. I have 3 years on this set doing this. So I'm really still in the testing stages of this, but so far my batteries are staying in good health. I think it is a good idea to equalize the cells every few months of use too, but that'd be after you use the battery and have a couple discharges/charges in the batteries history.
  • Batteries, even wet cells, don't magically discharge in a week or even a month when disconnected of all parasitic draws & left in storage.

    It is nice to give a wet cell a little top up every month but two months is no real issue at all. Construction, farm equipment, boats on moorings, spend months at a time untended & start right up, provided the battery was in good shape when put into storage.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Darklock wrote:
    Is it best to just keep it hooked up and let the panels and controller do their thing, or would I be better off disconnecting the battery and using some sort of battery maintainer/smart charger?


    I have heard argument on nearly everything this included but my position is "YES" provided you have a good controller.

    As someone said if panels get covered with snow.. Consider shore power and the on-board converter provided it's a good one. Magenetek 6300serkes.. NOT GOOD.
  • I disconnect my car battery for the winter. When I come home in the spring it starts right up.
  • Looks like I will just be lazy and let the panels work. Thanks.
  • I prefer a MPPT controller (PWMs are fine also).
    Just leave the solar connected and let the MPPT controller do all the thinking. They check the battery several times per second and make adjustments as needed.
    You are already done.
  • The answer depends to some extent on what the make and model of the charge controller. The Renogy charge controller makes most converters and smart chargers look sick.
  • Keep your new battery charged one way or another.
    Check the fluid level monthly and refill as necessary.
    Decide on how many cycles you want from your new battery and never go below that SOC percentage.
  • OK, quite a few "paths" that can be taken.

    1) disconnect house batteries from RV and solar, FLA batteries can sit for many months without needing to be recharged due to self discharging. FLAs can easily stored for 6 months or even up to a year without need for charging as long as they are completely disconnected from your RVs electrical system.

    2) Disconnect house batteries from RV but leave solar connected but you will need a controller that is able to drop to a storage mode voltage of 13.2V. At 13.2V the batteries will be maintained enough to cover the self discharge rate but not to high of a voltage to use a lot of water.

    3) Leave all connected but only solar charge.. Once again, charge controller needs to have a 13.2V storage voltage but, phantom draws from fridge, water heater, stereo devices may not allow the charge controller drop into storage mode voltage.

    4) Leave all connected plus solar and converter.. see comment number three.. The converter used in many RVs often have a difficult time dropping to a storage voltage of 13.2V due to high of phantom loads draw.

    While you can store a battery with a charging voltage higher like 13.4 or 13.6, it tends to boil the batteries dry which means you will need to check and fill the batteries often or risk them going dry.
  • If the panels do not get snowed on then let the solar keep them maintained.
    Just check on the water level once in a while.

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