RV batteries dead or not charging: battery, converter, or something else

Dead house batteries are one of the most common calls we take in Kern County, and heat is the reason: a rig that sat disconnected through a Bakersfield summer, batteries at partial charge the whole time, is a near-textbook setup for a bank that will not hold a charge when you need it. Some of those batteries are genuinely finished. A good number are fine, and the converter stopped charging them properly, which is a different repair with a different price.

Check this first (ten minutes)

Measure resting voltage at the battery with everything off and no shore power connected. Below about 12.2 volts suggests the battery is significantly discharged or sulfated.
Plug in shore power and re-measure. A healthy converter should push voltage up toward 13.2 to 14.4 volts. If it barely moves, the converter is suspect.
Check battery terminals and cables for corrosion or a loose connection, a simple and common cause of intermittent power.
Note how long the rig has been in storage and whether anything (a maintainer, solar) was keeping the battery charged during that time.
Look at the physical battery for bulging, leaking, or a swollen case, signs it is done regardless of what the meter says.

What is usually wrong

What you find	Likely cause	Fix and cost
Low resting voltage, does not rise on shore power	Failed converter	$400 to $900
Low resting voltage, rises properly on shore power	Battery itself likely sulfated/failing	Battery replacement (parts vary)
Voltage fine but intermittent power	Corroded terminal or loose connection	$150 to $350
Rig sat all summer disconnected, nothing works	Classic heat-driven battery discharge	Diagnose battery vs. converter first
Battery physically swollen or leaking	End of battery life, replace regardless of voltage reading	Battery replacement

Those ranges are from the pricing page, on top of the $75 to $150 trip fee and $125 to $190 hourly labor.

Why heat is the whole story here

Lead-acid batteries self-discharge at a rate that climbs with temperature, and Kern County gives them a lot of temperature to climb with. Bakersfield’s National Weather Service office confirmed a new record in July 2024 for eleven consecutive days at or above 105 degrees, and normal summer highs sit near 98 degrees for weeks at a stretch. A battery bank sitting through that, without a maintainer or solar keeping it topped off, loses charge and sulfates faster than the same bank would in a mild climate. This is largely preventable: a basic trickle charger or solar maintainer running through the hot months prevents most of the dead-battery calls we take.

What to expect on the call

Tell us how long the rig has been sitting, whether anything was maintaining charge, and the voltage readings if you were able to take them. We work on site across Bakersfield, Oildale, Rosedale, Shafter, Taft, Tehachapi, and the Kern River Valley. The repair cost calculator will price a range now.

Frequently Asked Questions

My RV batteries died over the summer while it sat in storage. Are they finished?

Often, yes. Lead-acid batteries self-discharge faster in heat, and a bank sitting at partial charge through a Bakersfield summer, especially a stretch of sustained 100-plus-degree days, sulfates as it sits. A battery that will not hold above about 12.2 volts after a full charge is generally done. A bank left on a working converter or a solar maintainer usually comes through fine.

How do I tell whether it is the battery or the converter?

Measure voltage at the battery with shore power connected and the battery disconnect on. A healthy converter puts out roughly 13.2 to 14.4 volts depending on its charge stage. If you see 12.4 volts or less while plugged in, the converter is not charging, and the battery may be innocent.

What does this cost to fix?

12V electrical work runs $150 to $900 on our pricing page, with converter replacement at the top of that range. Batteries themselves are parts: a pair of flooded 6V golf-cart batteries is a few hundred dollars, and lithium is a much larger conversation.

Should I switch to lithium given how hard heat is on lead-acid batteries here?

Worth considering if you dry camp or run a compressor fridge, since lithium tolerates heat and partial-state charging better than flooded lead-acid. It is often not worth it if the rig lives mostly on shore power. Lithium also needs a charger profile that suits it, so it is a system conversation rather than a drop-in swap on many older rigs. We will be straight about which you are.