On-Board Charger and Battery Storage

[Fishook]

What do I need to know about storing my deep cycle batteries and marine battery this winter? Can I leave the batteries in the boat and leave the charger plugged in? or do I need to maybe plug it in once/twice per month? The charger is vertically installed up under the port side counsel. I plan to leave the boat cover on all winter. Will this provide the needed ventilation? Is this a fire hazard? I did search for this on FM but did not find any related information. Thanks for any ideas or comments.

[Northlander]

I kept my batteries in the boat last year(1st time) and plugged in the on board charger once or twice a month. It did fine. I would keep the cover open while charging.

[shamrock7]

As long as your batteries are fully charged, you do not need to do anything. Charging once or twice through the winter will not hurt anything but shouldn't be necessary. It is best to disconnect all wires so if there is a small draw, your batteries will not freeze once drawn down. There are a lot of old wives tales out there on battery care. I have been storing 150 plus boats each winter for 26 years and find this works best.

[stick]

I have a 3 bank Guest charger, and I called up and talked to their engineering department, and they said that, with a "smart" charger, you can plug in and leave it plugged all winter...in fact it's best for the battery since there are only so many charging cycles that the batterys can go through. So, for the last 5 years or so, I have done that and the batteries are still going strong.

For what it's worth, I don't have the boat covered. I do keep the compartment door open, though.

[Whoaru99]

I do the same as stick - leave the batteries in the boat and charger plugged in all winter.

My batteries are 6 or 7 years old and they're not any type of specialty battery.

[Big-Al]

I have always left mine plugged in all winter and had extremely good luck with battery life. This year my boat is stored in a shed without power so I will haul a generator over a couple of times to throw a charge in them. It is really a pain to pull the deep cycles from where I have them installed.

[Hemlock]

What do you guys reccomend for a boat stored outside, all winterized and tarped up...take batteries out and keep in garage? My garage is heated, but not always. Basement of the house?

[wishing for walleyes]

I take all 5 of my batteries out and put them on a bench in my garage.I charge them all up and will go in january or febuary and trickle charge them again.Never leave them set on concrete as that will discharge a battery.

[shamrock7]

That is one of the old "wives tales" that I spoke of earlier. Here is an exert from an article that will come up if you GOOGLE "storing batteries on concrete".

Flooded Lead Acid Battery Storage

Trojan: Periods of inactivity can be extremely harmful to lead acid batteries. When placing a battery into storage, follow the recommendations below to insure that the battery remains healthy and ready for use.

NOTE: Storing, charging or operating batteries on concrete is perfectly OK. The most important things to avoid:

1. Freezing. Avoid locations where freezing temperature is expected. Keeping battery at a high state of charge will also prevent freezing. Freezing results in irreparable damage to battery's plates and container. [Freezing can happen between -19 F (40% charge) and -98 F (fully charged)]

2. Heat. Avoid direct exposure to heat sources, such as radiators or space heaters. Temperatures above 80° F accelerate the battery's self-discharge characteristics.

3. Step by step storage procedure: 1. Completely charge the battery before storing. 2. Store the battery in a cool, dry location, protected from the elements. 3. During storage, monitor the specific gravity (flooded) or voltage. Batteries in storage should be given a boost charge when they show a 70% charge or less. Completely charge the battery before re-activating.

For optimum performance, equalize the batteries (flooded) before putting them back into service. Refer to the Equalizing section for this procedure.

Continental Battery Storage:

Q: Will a battery rapidly self discharge if placed on concrete?

A: No, placing a battery on concrete will not cause it to discharge any faster than any other surface.

Q: Can I store a battery indefinitely?

A: No, a battery will self-discharge slowly over time. Allowing a battery to sit in a discharged state will ultimately lead to severe positive grid corrosion and battery failure. An unused battery should never be allowed to sit over 6 months without a recharge.

This is not intended to say anything negative about any previously posted info. I had the same opinion until an Exide Battery rep told me the facts.