# Marine Battery Installation Long Beach | Chargers & Battery Banks | Long Beach Marine Electric

> Boat batteries dying or not charging on shore power? Marine battery installation, chargers and parasitic-draw testing at your Long Beach slip. Call today.

URL: https://longbeachmarineelectric.com/marine-battery-installation/

Repair · Same-day callback

# Marine Battery Installation in Long Beach

Batteries dead every weekend, or not charging on shore power? Battery banks, chargers, switches and draw testing at your slip.

[Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)

![Marine electrician working at a DC distribution panel and battery bank in a boat engine room](/images/photos/marine-electrician-battery-bank-engine-room-panel-1408.webp)

-   Flooded · AGM · LiFePO4
-   Parasitic-draw testing
-   Battery chargers matched to chemistry
-   ABYC E-10 battery installation
-   Overcurrent protection at the battery
-   Free estimate within 24 hours

Last updated: October 6, 2026

[Long Beach Marine Electric](/) connects boat owners with licensed, insured marine electricians for marine battery installation and charging repairs: replacement start and house banks, battery chargers, battery switches and combiners, and the parasitic-draw testing that explains why a bank goes flat between weekends. A dead bank is more than an inconvenience at the dock. It's also the bilge pump's only power source while you're away.

## What happens on the first visit

1.  Load test of each battery, and a check of age and type. A 5-year-old AGM that tests weak is a replacement, not a mystery.
2.  Resting-voltage check after the boat sits, plus a measurement of current draw with everything switched off to find parasitic loads.
3.  Charger test on shore power: is it on, is it in the right mode for the battery chemistry, and is it actually delivering current?
4.  Inspection of terminals, cables, battery switch, fusing and hold-downs. Loose or corroded battery cables are a common cause of both no-start and fire.
5.  A written plan: what failed, what to replace, and a fixed price for parts and labor.

## Why boat batteries die in a Long Beach slip

Batteries on boats that sit Monday to Friday usually die for one of three reasons. A **parasitic draw** keeps pulling current with everything off: a stereo memory, a bilge-pump float stuck in the up position, a carbon-monoxide detector or a miswired accessory. A **failed or mis-set charger** leaves the bank on shore power but never charging, or overcharges and dries it out. Or the batteries are simply **at end of life**. Flooded and AGM batteries are typically rated for 300 to 600 cycles at 50% depth of discharge.

A clamp meter on the battery cable with everything switched off answers the first question in minutes. A draw of even half an amp empties a 100 Ah usable bank in about 8 days. That's why a boat that was fine on Sunday won't start the following Saturday.

## Choosing replacement batteries: flooded, AGM or lithium

Published 2026 price ranges for a 100 Ah deep-cycle battery are about **$90–$150 for flooded lead-acid, $200–$400 for AGM, and $500–$800 for LiFePO4 lithium**. Lead-acid batteries should only be discharged to about 50%, so a 100 Ah flooded or AGM battery gives roughly 50 Ah of usable power. A lithium battery can use 80–100% of its rating and is rated for thousands of cycles.

For most boats that sit in a slip on shore power, a like-for-like AGM swap is the sensible choice. If you anchor out, live aboard or run an inverter, a [lithium conversion](/lithium-battery-conversion/) can pay back, but it's a system change, not a drop-in swap: charger, alternator and battery protection all need to match.

## Chargers, switches and battery safety

A battery charger has to match the chemistry. AGM, flooded and lithium each need different absorption and float voltages, and a charger left in the wrong mode shortens battery life. Battery cables need overcurrent protection close to the battery, secure hold-downs so the bank can't shift in a seaway, and terminals covered against accidental shorts. Improper battery installation is a leading cause of the "other DC electrical" fires that account for about 15% of boat fires in BoatUS claims.

## Insurance, warranty and who pays

Battery replacement is owner-paid. Batteries are a wear item that insurers don't cover unless they're damaged in a covered loss. Labor for a like-for-like swap is usually one to two hours. Charger replacement or a new battery switch adds parts and an hour or two. You get a fixed parts-and-labor price before work starts.

## What's included

-   Load test of every battery
-   Parasitic-draw measurement
-   Charger output and mode check
-   Cable, terminal and fuse inspection
-   Battery replacement and secure hold-downs
-   Charger and battery switch installation
-   Chemistry-matched charge settings
-   Old battery removal for recycling

## DIY vs cheap fix vs proper battery work

DIY

Cheap operator

Proper marine work

Diagnosis

Buy a new battery

Swap the battery only

Load, draw and charger tests first

Bank

Mix old and new

Whatever's in stock

Matched type, age and capacity

Charger

Left on default mode

Not checked

Profile set to battery chemistry

Safety

Unfused, loose

Hold-downs skipped

Fused near the battery, secured, terminals covered

Result

Dead again next month

Dead again next season

Root cause fixed

## Related resources

-   [Why Does My Boat Battery Keep Dying?](/guide/boat-battery-keeps-dying/)
-   [Boat Batteries Not Charging on Shore Power: What to Check](/guide/boat-batteries-not-charging-on-shore-power/)
-   [Lithium vs AGM Marine Batteries: Which Is Worth It for Your Boat?](/guide/lithium-vs-agm-marine-batteries/)

## Sources

-   [LiTime: deep-cycle marine battery prices (Jul 2026)](https://www.litime.com/blogs/buying-guides/deep-cycle-marine-battery-prices-cost-comparison)
-   [BoatUS claims data via Quimby's Cruising Guide](https://quimbyscruisingguide.com/how-boat-fires-happen/)
-   [US Harbors: lithium boat batteries (Jul 2026)](https://www.usharbors.com/2026/07/lithium-boat-batteries-what-boaters-need-to-know-about-making-the-switch/)

Batteries dead now?

A dead bank also means a dead bilge pump. Call for a same-day callback.

[(562) 374-7233](tel:+15623747233)

Mon–Sat 7am–6pm · Free estimate within 24 hours

Standards applied

-   ABYC E-10 (storage batteries)
-   ABYC E-11 (DC systems)
-   ABYC A-31 (battery chargers)
-   UL 1426 battery cable

[Estimate your cost](/tools/marine-electrical-cost-estimator/)

How it works

## How marine battery installation works

1.  01
    
    ### Tell us the symptom
    
    Dead on arrival, slow cranking, or a charger that never shows charging. You get a callback the same day.
    
2.  02
    
    ### Test the bank and draw
    
    Load test, resting voltage and a clamp-meter draw test with everything off.
    
3.  03
    
    ### Fixed price
    
    A written price for batteries, charger or wiring, with options by chemistry.
    
4.  04
    
    ### Install and set up
    
    Batteries secured, fused and connected; charger set to the correct profile and verified on shore power.
    

Get marine battery installation at your slip today

Same-day callback. Written price before any work.

[Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)

Straight answers

## Marine Battery Installation questions

### Why does my boat battery die when it's plugged into shore power?

Either the charger isn't charging (failed, tripped breaker, wrong mode or a blown fuse on its output) or a load is drawing more than the charger supplies. A meter on the charger output and the battery cable shows which in a few minutes.

### How long should marine batteries last?

Flooded and AGM deep-cycle batteries are typically rated for about 300–600 cycles at 50% depth of discharge, which works out to several seasons for most slip-kept boats. Heat, chronic undercharging and deep discharges shorten that. LiFePO4 batteries are rated for 2,000–4,000+ cycles.

### Can I mix old and new batteries in a bank?

It's not recommended. Batteries wired together share charge, so a weak old battery drags a new one down and shortens its life. Replace the whole bank, ideally with the same type, age and capacity.

### What does a battery replacement cost?

Batteries run about $90–$150 (flooded), $200–$400 (AGM) or $500–$800 (LiFePO4) per 100 Ah in 2026, plus typically one to two hours of labor at $140–$200/hr for a like-for-like swap.

### Who does the work, and how do I know they’re qualified?

Long Beach Marine Electric is a free service that connects you with an independent, licensed and insured marine electrician who holds the American Boat & Yacht Council (ABYC) Marine Electrical Certification. Ask your electrician for proof of license and insurance before work starts.

## Related services

[Lithium Battery ConversionLiFePO4 house banks installed to ABYC E-13, with matched chargers, alternator regulation, DC-DC charging and BMS integration.](/lithium-battery-conversion/) [Marine Alternator RepairBattery won't charge with the engine running? Covers regulators, alternators, starters and charging-circuit faults.](/marine-alternator-repair/) [Marine Inverter InstallationPure-sine inverter/chargers sized to your loads and wired with proper transfer switching, so they don't trip the pedestal.](/marine-inverter-installation/)

Stop replacing batteries that didn't fail

[Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)