Onboard Systems
Battery and Charging System Repair: Cost, Hours and Process in Hacienda Heights
Battery and charging system repair addresses the house bank and everything that refills it: the converter or inverter charger, the solar controller, the DC to DC charger and the disconnect and isolation hardware between them. A bank that will not hold is usually a charging profile problem before it is a battery problem.
What brings this in
- A bank that reads full at rest and drops below 12 volts within an hour of use
- Batteries hot to the touch or venting a sulfur smell after a night on shore power
- Water loss in a flooded bank that needs topping every few weeks
- Charging voltage stuck at 13.2 volts and never rising into an absorption stage
- One battery in a bank measurably hotter or lower than its neighbors
- Case swelling or a distorted top on an AGM battery
- A monitor showing full while the coach behaves as though the bank is empty
- Cranking the generator drops coach voltage far enough to reset the control board
This job, by the numbers
$500 to $5,500
2 to 10 hours
In depth diagnostic, 1 hour at $285. One hour minimum. Credited to an authorized repair.
Parts and assemblies we work with
Progressive Dynamics, WFCO, Magnum, Victron, Battle Born, Lion Energy
Most dead banks were killed by the charger
Lead acid chemistry wants a three stage profile: bulk, absorption, float. A single stage converter that sits at 13.2 volts forever never completes absorption, so the plates sulfate a little more each cycle and capacity walks down over two seasons. The owner replaces the batteries, the converter is untouched, and the new bank dies on the same schedule.
The opposite failure is just as common. A charger stuck in a high stage cooks the electrolyte out of a flooded bank and swells an AGM. Hot batteries after a night on shore power is not normal and it is not the battery's fault.
So the diagnosis is always both halves. We load test the bank to get real capacity, then read the charger through a full cycle to see whether it is actually staging. Selling batteries without reading the charger is the most common way this repair gets done wrong, and it is a repeat customer in the worst sense.
- Single stage converter output that never reaches absorption voltage
- Temperature compensation missing or a failed remote temperature sensor
- Mismatched batteries in a bank, different age, capacity or chemistry
- Undersized or corroded interconnect cables causing uneven charge
- A failed battery disconnect or isolator leaving part of the bank offline
- A solar controller set to the wrong chemistry profile after a battery change
Bank testing, and why a voltmeter is not a test
Resting voltage tells you state of charge, not capacity. A tired battery reaches 12.7 volts happily and then falls over the moment you ask for current, which is exactly the symptom owners describe as batteries that will not hold.
We load test each battery individually, not the bank as a unit, because a bank averages. One bad cell in a four battery string drags the other three down and then gets replaced along with them if nobody looked. Testing individually is the difference between a one battery invoice and a four battery invoice.
Age matters for the mixing decision. Adding one new battery to a three year old string pulls the new one down to the old ones rather than lifting the string, so if the string is past roughly half its service life we recommend replacing it together. If it is early, we replace the failed unit only and say so.
What it costs and how long the bank should last
Flooded lead acid in this climate realistically returns three to five years, AGM four to seven. Heat is the driver, and a coach stored uncovered in the San Gabriel Valley sees battery compartment temperatures that shorten both of those numbers. Deep cycling below fifty percent regularly cuts them further.
Diagnosis on this page is the in depth diagnostic tier at one hour and $285, credited against an authorized repair. Labor is the posted mechanical and electrical rate of $260 per hour. A straightforward pair of group 27 batteries with cable service sits near the bottom of the band. A four battery bank plus a converter, new interconnects and a monitor shunt reaches the top of it.
If you are already replacing a bank, that is the moment to have the lithium conversation rather than after. The charging hardware decisions are the same hardware either way, and doing it twice costs the labor twice.
Scope
What this line item does not include
- Chassis starting batteries and alternator charging are truck shop work rather than coach work.
- We do not perform battery replacement at a storage yard or a residence. Bank work is bay work.
- A lithium conversion is a separate upgrade line item because it changes the charging profile.
Being explicit about the boundary is faster than discovering it at pickup. If the work you need sits outside this line item we will say so at intake and point you at the right one.
Questions
Battery and Charging System Repair questions
Why will my RV batteries not hold a charge?
Either the batteries have lost capacity or the charger never finishes the job. Both are common and they look identical from the driver seat. We load test each battery individually for real capacity, then read the converter or charger through a cycle to confirm it stages properly. Replacing a bank behind a single stage converter buys you the same failure in about two seasons.
Do I have to replace all the batteries at once?
It depends where the string is in its life. Early on, replacing only the failed battery is reasonable. Past roughly half of service life, a new battery added to old ones gets pulled down rather than lifting the string, so replacing together is the better spend. We test individually and tell you which situation you are in instead of defaulting to the larger invoice.
How long should RV house batteries last in Southern California?
Flooded lead acid realistically returns three to five years here and AGM four to seven. Heat is what shortens them, and a battery compartment on a coach stored uncovered in the San Gabriel Valley runs hot most of the year. Regular discharge below half capacity shortens them further regardless of chemistry.
Can you tell whether it is the battery or the converter before I authorize parts?
Yes, and that is the whole purpose of the diagnostic hour. The load test gives real capacity per battery and the charger reading shows whether it stages. You get both numbers before anything is ordered, and the diagnostic is credited against the repair you authorize.
Related work
Often done at the same time
$1,500 to $12,000
Lithium Battery Upgrade
LiFePO4 bank conversion with charger, controller, inverter and cable work matched to the new chemistry.
$750 to $4,500
Inverter and Converter Repair
Diagnosis and replacement of coach converters, inverters and combined inverter chargers, including transfer and cutoff settings.
$1,500 to $12,000 plus
Solar Panel Installation and Repair
Rooftop array installation, controller wiring and sealed penetrations, plus diagnosis of arrays that stopped producing.
$285 to $5,000 plus
12 Volt Electrical Repair
DC side diagnosis and repair: battery bank, distribution panel, grounds and the branch circuits off them.
Get a firm number on battery and charging system repair
The band on this page is honest, and the in depth diagnostic at 1 hour at $285 turns it into a firm number. One hour minimum. Credited to an authorized repair. We are 18.4 miles from Hacienda Heights.