Questions about onboard battery chargers

[Thump Doctor]

I know how battery chargers work, but do marine chargers do anything that regular 12v chargers dont? I currently use a portable charger to recharger my three batts, but would like to upgrade to a fixed unit if its worth it. Thanks. P.S. Any other details/ tipos on onboard chargers are welcome.

[Barnacle Bill]

If you are referring to an on-board charger then yes, they are by far the best way to go. When you get back from fishing, you plug it in and then forget it until time to go again.

[Good Stuff]

If you are referring to an on-board charger then yes, they are by far the best way to go. When you get back from fishing, you plug it in and then forget it until time to go again.

But how are they different from any other charger like mine that I can plug in and forget about?

[RangerZ21]

I've got a 4 bank on board charger and was told by the dealer after the batteries are charged to unplug it.

[Cray]

If only charging 1 battery, no real difference if your charger has the maintainer function. Most onboards are for 2 or more batterys. wire up charge trolling and cranking or 2 trolling or more. I like my 2 bank because i never have to worry about a dead cranking battery along with trolling battery. A D D sometimes forget to turn off things = dead cranking.

[majflyboy]

But how are they different from any other charger like mine that I can plug in and forget about?

You can't just plug yours in and forget about it. You have to haul it out, connect alligator clips to posts, check back to see if that battery is charged and if it is, reconnect to the next battery. An on-board charger is already connected to the batteries and all you have to do is plug the cord into a normal wall outlet and that's about it. They are worth their weight in gold.

[CatFan]

While there are portable chargers that work the same way an onboard works, most don't. Virtually all onboard chargers are three stage chargers that charge the battery rapidly when it is deeply discharged, then reduce the current as the battery nears full charge, then drop the charge rate below the gassing voltage for maintenance.

Most cheap portables never get down to a safe level, and some don't taper the charge at all. Portables like the Black and Decker or Schumacher Speed Charge are good.

Nothing beats a mulit-bank onboard. All batteries are charged ASAP and kept at full charge. Makes your batteries last as long as possible and saves you money. Even letting one battery sit for 6 or 8 hours while another charges does damage to that battery.

[Thump Doctor]

So what type of charger would i need to charge three 12v?

[Barnacle Bill]

You need a 3 bank on-board charger. If you do a lot of back to back fishing where you go several days in a row then you might consider a 10 amp charger. If not a 5 amp will work just fine. I used a 5 amp Pro Mariner from Bass Pro for years and in the spring when I went fishing daily for a solid week it kept my batteries charged. With 3 batteries and a lead connected to each one it would provide a max of 3 amps charge to each one. However if one of the batteries did not need charging (like the starting battery) it would automatically send those available amps to the batteries that do need it. There are a lot to choose from and everyone has their favorite. Just remember, like everything else in the world, you normally get what you pay for.

[Thump Doctor]

Thanks for the info everbody... Now i have to do some research...