RV Battery Draining Fast? – (Checks you Can Do + Possible Fixes)

If your RV’s batteries are losing power sooner than expected, figuring out what and where to start looking can be a challenge.

This can be the more confusing if it is a new RV or you’ve got a brand new set of batteries installed. Could it be there is an appliance(s) draining the battery, or a case of a bad battery?

How can you find the likely fault without spending so much time or purchasing replacement parts such as batteries or others that may turn out not to be the cause?

This post provides you with a guide intended to help you identify the likely reasons why your RV batteries may be draining so fast in a time-efficient and cost-effective way. If this is your aim then read on.

Common Reasons Why an RV’s Battery may be Draining Fast

If the RV batteries seem to be draining fast, check the following:

#1. Confirm that there is no unusual or excessive power draws by connected appliances. The connected appliances may be drawing more power than you expect. To check this perform a power audit of the battery system.

First, work out how much runtime you can expect with the connected appliances on the battery or inverter.

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You can use this handy calculator to work out an indicative runtime on battery power.

Depending on the outcome of the audit you may need to add an additional battery, and use an additional power source to complement the existing one such as purchasing an inverter generator if it turns out not to be adequate.

#2. Check that the battery charger or solar panels (if using solar ) are adequately sized to fully charge your battery. Are you are using a trickle charger or solar?

Trickle chargers only pump out a small current, usually 1-2 amps, and can take a long time to fully charge a battery. You may also be interested in this post. How long to charge a battery at 2 amps

Only use the trickle charger or maintainer to keep the battery topped up otherwise use a fast battery charger or the RV’s converter to charge the battery bank.

If using the RV’s converter to charge the battery bank, check that the RV is plugged into shore power and that the breaker is not tripped.

#3. The batteries may be faulty and need to be replaced. If you confirm that the batteries are being charged and the charging source is adequately sized with no phantom loads then it might be that the batteries are fully charged and need to be replaced.

A quick check you can do is to fully charge the battery bank and then disconnect it. If it drains after a few hours or it’s bulging or heats up during the charging process then it is probably faulty.

You can arrange for the batteries to be load tested at an AutoZone to confirm if they are good or otherwise.

Appliances Draining the Battery (That You may not be Aware of)

Here are some of the appliances that you’re likely to find connected and running off the RV’s battery setup depending on the power options available and how the internal wiring is done.

You can use this as an initial guide to check what appliances may be draining the battery bank’s power.

  • 12V fridge
  • space heater
  • Electric slides, and 12V fans.

Note: Some appliances may be on a timer or may be deactivated by a door switch or thermostat. Should this fail, the appliance can continue to drain battery power. This list is not exhaustive.

What to Do if your Batteries Draining Fast

If your batteries are draining fast, in addition to establishing the underlying causes, consider the following:

#1. Obtain alternative power sources

Consider getting an inverter generator to complement the available power options in case there is no shore power available or the solar panels are not able to fully charge the battery.

#2. Consider installing a quality power meter with a shunt to monitor the battery bank charge status.

It can provide an indication of expected runtime to make adjustments to your appliance usage and to avoid being taken by surprise.

#3. Install a battery disconnect switch to disconnect all appliances from the battery bank to stop the battery drain.

Closing Thoughts

If your RV batteries are draining fast, it might be that the charging system is undersized, there are additional appliances connected to and draining the battery, or a case that the battery bank is faulty.

Consider obtaining an additional power source such as an inverter generator to complement your energy needs.

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