Battery Charging

[Themis]

I just bought this:

http://www.homedepot.com/prel80/HDUS/EN ... =100375932

I had always thought that the marina charged the batteries in my boats before they launched. This year I have my boat at my house, and the guys who would launch it told me I should charge my own batteries, as they don't do it by default (They just start the engines up and run em for a while).

The charger above has several amp settings (2/4/10/20/60). Which one(s) should I use to fully charge my batteries before they come to pick up my boat and drop it in?

 

[Porkchunker]

I have one of these mounted in each of my boats. I plug them in overnight or for a couple of hours while prepping the boat for launch. Being fully digital, they will not overcharge a battery.

http://www.batterystuff.com/battery-cha ... P15-2.html

Don't forget to check the water levels on a regular basis. Hooking a charger up to a battery for any length of time can, over time, boil the water off, exposing the plates. Once the plates are exposed to the air, the battery is essentially useless, and sparks can jump between plates, causing a hydrogen explosion. :shock: :shock: :shock:

 

[cbigma]

I've always been taught that charging batteries is like making good barbeque, "Low and Slow". I think the theory is that you put less stress on the plates by "trickle charging", rather than running them up fast and running the risk of overheating.

This makes sense with the old "open" lead/acid types. Not sure what wisdom fits the newer "sealed" gel batteries.

This of course assumes you have a few days to trickle them on low before you splash...

 

[DaleH]

Sal:

Battery Type Switch:
Can you clarify on the '5 different type of batteries" selector switch that it has? Does it have a mode for deep cycle batteries? That is what you should use if you use either deep cycle or combo (dual purpose) starting/deep cycle batteries.


Charging Amps/Rate:
Typically the lower amp rates are for smaller batteries or to 'gently' top one off prior to use once it had already been charged post-season. ALWAYS charge your battery after you take it out of the boat.

That fastest amp charging rate, say 60, is strictly for speed. It'll charge quick but is not nenessarily the best rate to use for best life and performance.

On typical chargers, use 10 amps for most charging needs, IMHO. Like John says, slow(er) is key - so see what your manual says for any difference in charging performance between 4 and 10 amps.

Also note that the deep cycle charging mode differs from the auto regular mode in that the charger shuts off in regualr mode once charged. The plates on a deep cycle or dual purpose battery are different, rather than pure starting power, they are configured to be drawn down and then build back up. Most deep cycle charging modes therefore charge the battery, but pause or pulse to 'condition' at various states of charge. Once charged, the machine doesn't shut off either, it continually monitors and pulse the battery.

I don't advise keeping a battery hooked up to any machine for any length time and from what I've read, most trickle chargers are practically useless. Also keep the battery clean. Remember that to get the most ACCURATE state of charge reading (hydrometer), you really need to wait a day or two AFTER charging for any surface effect to dissipate.

I charge once in the Fall after coming out of the boat and then a few weeks before installing and I'll get 5-6 years out the batteries, though they are swapped out after the 4th season. I keep a few handy for small skiff bilge pump use, or other chores ... plus as backup !

 

[Themis]

Thanks guys.

 

[Megabyte]

I use this float charger sourced from Harbor Freight.

http://www.harborfreight.com/cpi/ctaf/D ... mber=42292

 

[andertonm]

As a member of NAPA Autocare, we get some pretty decent training. Their electrical trainers told us that when a standard starter battery has been discharged for a while and the plates sulfate, you need to pull a lot of current (40 amps) for an extended period of time (2+ hours) to cook off the sulfating and then follow up at 10 amps for a couple of hours. I have done this and verified success with a conductance tester.

Unless you have a valid deep-cycle requirement (e.g. house power), it is my opinion you should avoid deep cycle batteries like the plague. They are extremely difficult to bring back to life when allowed to go completely dead. When I first started boating, I thought deep cycle batteries were "better" batteries. I bought them to use as starting batteries and ended up very frustrated. I worked at West Marine for a while and we got lots of deep cycle back for warranty replacement because people let them go dead and they wouldn't re-charge from the boat charging system or home chargers.