Off Season Trickle Charging off Boat

[jpendoley]

I’ve removed my AGM start battery from my boat and would like to keep it in float in my shop. Can anyone recommend an inexpensive battery charger? Would prefer something that let’s me adjust the charge rate for different FLA and AGM charging profiles. This is for a maintenance charge not absorption or bulk.
Thinking there must be an inexpensive programmable trickle charger available.

[lmxr]

A lab power supply? The low current ones are rather affordable. Technically they're not designed to charge batteries but they should do the job. Best to limit the maximum current to less than 1/2 or 2/3 of rated current to avoid them overheating, and preferably buy one from a reputable shop as there are a lot of fakes around.

[rslifkin]

For cars and other stuff that may sit a lot, I have a few Battery Minder 1510s around the garage. They're a small (1.5 amp) 3 stage charger and temperature compensated. Standard voltage settings are adequate for most flooded and AGM batteries I've encountered (might be a little too much voltage for gels). I've had AGM batteries spend a year straight hooked up to one sitting in float with no issues.

[David993s]

Probably just the use of a generic term, but you don't want a "trickle charger". You want what's referred to as a battery "tender" or "maintainer". A trickle charger will deliver a constant supply of charge, ultimately overcharging and burning up the battery. A "maintainer" or "tender' has a microprocessor in it that delivers a small amount of charge and then shuts off automatically when the battery is fully charged. A tender will maintain a battery in good health for a very long time.

Also, be sure to get a tender that is specifically for an AGM battery, not one for a lead acid battery.
Cheers.

[glenn.225]

You are probably aware, but don't store a battery directly on a concrete floor. Always have some form of separation.

[rslifkin]

Originally Posted by glenn.225

You are probably aware, but don't store a battery directly on a concrete floor. Always have some form of separation.

This is an old wives tale from before plastic cased batteries. Modern batteries can't be harmed by sitting on concrete. Dirt on top conducting some power between the terminals is more likely to be an issue.

[glenn.225]

I guess it depends on conditions. In a climate controlled, dry place, it might be OK. But if there are wide temperature swings and higher humidity, it will damage them. I have seen two in the past 5 years, one in my sons garage and one in my buddies garage. Both good batteries when removed.

[rslifkin]

Originally Posted by glenn.225

I guess it depends on conditions. In a climate controlled, dry place, it might be OK. But if there are wide temperature swings and higher humidity, it will damage them. I have seen two in the past 5 years, one in my sons garage and one in my buddies garage. Both good batteries when removed.

What was the damage you experienced? Unless it was mechanical damage to the case, the floor didn't cause it. Assuming a battery that isn't leaking acid, how is concrete against plastic supposed to harm it?