I have a vehicle I am storing for the winter, but do want to start it up on occasion just to keep it fresh. my question is this. I put a trickle charger on the battery to keep it charged up, its one of those chargers you can leave on indefinitely, once the green light goes on the charger, it goes into maintanance mode. but I've had the charger on for a week now and it seems the battery won't take a full charge. to put the battery charger into maintance mode. is it dangerous to keep charging a battery that won't fully charge up?

 

Feel the battery with your hand. If it's cool or a little bit warm, you should be ok. If it feels like it's hot, I would get a new battery. No smoking around it either while it's charging.

 

How old is the battery, is it one you can check the water level or if it has a eye - is it green all around or just part way?

 

Dave the battery feels cool to the touch, and I've had the charger on it for about five days. bigred the battery is just over a year old, I checked the fluid level in each cell and the plates are all covered. I can't figure why a yr old battery won't fully charge, is that comman or do I maybe have a weak cell. the battery works fine. should I not leave the charger on it full time or just charge it in intervels. thanks for the advice

 

You could just charge it once a month for a couple of days rather than leave it on all the time. Especially if you are not going to use it during the winter. This would not overcharge the battery and would keep the battery from drying out.

 

thanks bigred I'll do that. speaking of batteries, I was talking to a guy the other night at a hockey game, and he said he shut his truck off and went into a store for something, and when he came out his battery had exploded, turns out the voltage regulator was screwed and must of over charged the battery, sounds dangerous. I definitely won't leave that charger on full time

 

If your going to store it for long period of time NAPA has an automatic charger/Maintainer PN# 85-300A that only charges the battery when needed. It hard wires to the vehicle. Have one on each vehicle that I put down, Has been working great for the past 4 years, Haven't had to replace a single Battery

 

my charger is a maintaner too, I just don't want to leave it on full time because the battery won't fully charge up for some reason, so the charger is charging full time. seems like that might be dangerous

 

This is an old post, but applicable to this time of year. Battery maintainers are just that - they maintain a full charge. You can fill a swimming pool with a squirt gun but that's not the way to go. Moderate outgassing is "good" and necessary but the charger should be "sized" to the capacity of the battery to prevent prolonged outgassing, some "smart" chargers automatically switch to a float charge to prevent this. The classic Schumaker charger many people are familiar with is just about perfect for an auto start battery. Usually several hours or overnight at 2 or 6 amp setting will bring even a discharged battery back to 100%, then the maintenance type charger can be used. You can "reboot" a smart charger by unplugging it and plugging back but it may take quite a while.
The nice thing is that there's no danger of forgetting to disconnect it like the "dumb" chargers.