Can I use a car battery charger on a marine battery?

[ClarencePeters]

Hi all

Quick question. I'm getting a little inflatable Intex boat and electric trolling motor to keep in the beach hut here for some fun in the summer.

I have an old bog standard halford car battery charger in the garage and was wondering if that would work on the deep cycle marine battery that i'll need for the electric motor?

Thanks

[GILow]

Define “bog standard”. Do you mean non-multistage? If so, I wouldn’t do it without being prepared to carefully monitor voltages with a decent meter while charging.

Also, what battery chemistry?

Seriously, small smart chargers are so cheap now I wouldn’t risk it myself.

[letsgetsailing3]

Yes, will work. Is it a "smart" charger? A trickle charger?

The one thing to be careful about is charging modes, depending on the technology used. Newer "smart" battery chargers are better at adjusting their charging rates based on the battery voltage, so if it's a really old one you'd have to watch it a lot more closely.

[S/V Illusion]

The more you use it, the shorter the battery lifespan will be. Typical car chargers are intended to revive a dead battery, not maintain it.

[GordMay]

Greetings and welcome aboard the CF, Clarence.

[zeehag]

yes. batteries are batteries. make sure you use correct settings on charger.

[a64pilot]

Only thing is that most old style car chargers put out quite high voltages and work fine, but you don’t want to leave them on the battery for extended times, you want to disconnect as soon as they battery is charged

[john61ct]

Originally Posted by zeehag

yes. batteries are batteries. make sure you use correct settings on charger.

Many garage style chargers have zero settings.

No changing voltage, one stage only like a power supply, no Float nothing.

An old one may not even keep voltage consistent.

Many are grossly underpowered compared to the current needed by a large bank.

So the answer is "it depends".

If it's a small cheap bank you don't care about longevity, then YES.

With a bank you care about, if you are willing to stand by, measure volts and amps and know what the bank requires

then if the charger's output can be made to match you're all set

or maybe you will be willing to act as a "human regulator" each cycle.

Otherwise, NO.

[zeehag]

the issue is charging a battery for a minnkota or equivalent electric motor for a dinghy. easy peasy. autozone sells CHEAP car chargers with settings 6v/2A, 12v/6a/12 v/2a.
the 6v 2a will charge any motorcycle battery or golf cart battery, is a SETTING chosen by moving a switch from one setting to another.
the ones without settings are pre 1990. try searching auto zone for your cheapest battery charger. is what i am using temporarily.
the electric motor will charge nicely with these chargers from cheapville.
no issue. done and done.

ps in marine environment these cheapville chargers actually last 4 years

[Cheechako]

Yes a car charger will work. But you may need to pay attention, turn it off when the battery is full etc.

[roland stockham]

No. because you are going to be moving the battery regularly you are going to want a sealed battery of some kind. They are fragile an fussy about charge rates and if you overcharge them once they are toast. You will need a proper deep cycle charger with 3 stages and setting for the correct battery construction you use. None 'smart' chargers are only designed to maintain batteries not recharge them which needs a hight voltage

[ferrailleur]

Originally Posted by a64pilot

Only thing is that most old style car chargers put out quite high voltages and work fine, but you don’t want to leave them on the battery for extended times, you want to disconnect as soon as they battery is charged

well said.... they work fine as long as you monitor the voltage input...

[Bawlmer]

Yes...IF you remember to turn it off when it is finished charging. I had the exact arrangement when I lived in FL. It worked well as long as you don't leave it on forever. If you leave it on for over a few days it will cook your battery. I know this from experience.

[hellosailor]

Roland makes a good point. Unless you buy your clothing by the pound at GoodWill, wet lead battery acid burns can become really expensive. If you are stuck with one--at least make sure it is in a battery box so you get sloshed less.

A NOCO Genius series charger ($50-60 and up typically) or similar is a very good idea. They take care of all battery chemistries, optimize the charge, fall back to float so they won't overcharge...Set it and forget it, and you won't have to worry about murdering your battery. Or blowing it up.

[hamburking]

Please don't flame me if I'm wrong here, but my understanding was that MARINE chargers were protected against internal sparking, because boat environments tend to be kinda explody. Otherwise, the chargers are the same.

That's not to say that a charger intended for an FLA battery is suitable to charge a AGM battery.

However, the SMART chargers are designed for unattended use. If you have a flat battery, and you plug it in overnight, you'll likely be fine. But leave it for a week and you could have thermal runaway and blow up the whole place!

The other consideration is POWER...how many AMPS is the charger? You need the right size. Too small and charging will take forever. Too big and you destroy the battery.

I seem to have many friends who are excellent at destroying batteries. Its not rocket science. Done right, your battery(s) will last for years.