'Manual' Battery Tending

[Jonah]

Hi all,

I have two batteries on my Adventure, and have inherited two manual battery charges. Each one has a 6-amp and 2-amp setting for 12V. I've read in other threads (listed below) that the easiest and safest way to care for batteries during the winter is to hook them up to a 'Battery Tender', or some sort of automated charger that will prevent over-charging, etc. But given that I already have these two chargers, and given that I work from home and walk right past the chargers several times per day, I'd like to try using these instead.

So, does anyone have advice on how to use these most effectively this winter? Could I simply plug them in for a few hours (on 2 amps) once per week? Each charger also has a display to show me how many amps the battery is actually drawing, in case that could be used as a way of gauging how full they are? I also have a multimeter, of course.

Thanks for any advice!

http://www.greatgrady.com/forum/viewtopic.php?f=2&t=21537&p=132059&hilit=battery+in+winter#p132059

http://www.greatgrady.com/forum/viewtopic.php?f=2&t=23430&start=15 (Especially Lt. Mike's comments.)

 

[seasick]

Hi all,

I have two batteries on my Adventure, and have inherited two manual battery charges. Each one has a 6-amp and 2-amp setting for 12V. I've read in other threads (listed below) that the easiest and safest way to care for batteries during the winter is to hook them up to a 'Battery Tender', or some sort of automated charger that will prevent over-charging, etc. But given that I already have these two chargers, and given that I work from home and walk right past the chargers several times per day, I'd like to try using these instead.

So, does anyone have advice on how to use these most effectively this winter? Could I simply plug them in for a few hours (on 2 amps) once per week? Each charger also has a display to show me how many amps the battery is actually drawing, in case that could be used as a way of gauging how full they are? I also have a multimeter, of course.

Thanks for any advice!

http://www.greatgrady.com/forum/viewtopic.php?f=2&t=21537&p=132059&hilit=battery+in+winter#p132059

http://www.greatgrady.com/forum/viewtopic.php?f=2&t=23430&start=15 (Especially Lt. Mike's comments.)

If the batteries are good and fully charged, and you don't use them during the winter, you can just leave them alone ( remove the negative cables. I used to remove my batteries and top off the charge every month or so but after seeing that many folks at my club just leave them, I decided to do the same with no issues for the last 5 years or more). When a lead acid battery discharges, the freezing point of the electrolyte increases. If the electrolyte freezes, your battery can be damaged. The freezing point for a fully charged lead acid battery is about -76F but if fully discharged, that rises to +32F

Also note that if your chargers are not 'smart" where they sense the charge status and adjust the charge current, it is possible to overheat your batteries and damage them. Worst case is that the electrolyte boils although at 2 amps that probably won't happen.
In the spring put the chargers on to top off the batteries prior to first use.

 

[Jonah]

Thanks seasick,

So, when it comes time to top them off in the spring, can I do that without removing them from the boat? Can I just put the charger clips onto the battery terminals, with all boat wires still attached, and top them off?

 

[DennisG01]

The number one thing you can do for overall battery health and longevity is to always keep them on a charge. But you have to be careful - even a 1amp "trickle" charger can boil a battery. You can use what you have (without removing any wires and with the alligator clips), but I would just do it for a few hours once a week or so. Maybe check the fluid level once a month. As mentioned above, you can charge it up good and then just remove the negative battery leads for the Winter and the battery will be just fine. Probably not "as" good as a constant charge, but still plenty fine. Something like a Battery Minder would be a FANTASTIC investment - it can be left on year round and will never cook the battery. In fact, it will likely lengthen the battery's life due to it's ability to trickle down to miniscule amperage (even turning off when needed) and it's desulphation phase. Google them. I have a bunch of these little guys and use them on all types of batteries. In fact, I have two hooked up to my Suburban (diesel - two batteries) right now and have been that way for close to a year without ever taking them off (there's some issues with the engine I have to address). Got another two on my boat's batteries up in Maine. Plus some various ones elsewhere.

 

[seasick]

Thanks seasick,

So, when it comes time to top them off in the spring, can I do that without removing them from the boat? Can I just put the charger clips onto the battery terminals, with all boat wires still attached, and top them off?

Yes but keep the battery switch set to OFF. In theory the switch can be on but if for whatever reason there was a spike in your AC or a nearby lightning strike, very high voltages can travel through the charger and if the battery switch is on through the electronics.
Of course even with the switch OFF a large enough lightning hit can easily jump an open switch.

I kind of agree with Dennis about the battery tender but in my case the vessel is stored on the ground at a marina for the winter and electric is an issue. If the vessel is at your home and running a power cord isn't a problem, then a smart charger is fine. I just don't find a need for one for my 208. As I said, my last set of batteries (both starting) lasted 7 years.

 

[Lt.Mike]

but in my case the vessel is stored on the ground at a marina for the winter and electric is an issue.If the vessel is at your home and running a power cord isn't a problem

:?: Take the batteries out and put them aside at your house for the winter with a battery tender hooked up. They don't have to stay in the boat.
There can't be a more basic maintenance chore for your boat.

 

[seasick]

but in my case the vessel is stored on the ground at a marina for the winter and electric is an issue.If the vessel is at your home and running a power cord isn't a problem

:?: Take the batteries out and put them aside at your house for the winter with a battery tender hooked up. They don't have to stay in the boat.
There can't be a more basic maintenance chore for your boat.

Mike, I used to do that but as I got older, lifting the dang batteries out of the locker and off and on the boat on a trailer was becoming too much work

 

[Lt.Mike]

That's why we have kids :wink:

 

[freddy063]

You could put it on a timer. Set it for what you think per day.

 

[seasick]

You could put it on a timer. Set it for what you think per day.

I have wondered about this approach. If a timer is added to the AC side, when power is off but the dc leads are still connected to the battery, does the charger actually draw some current from the battery (in other words act as a load). I wouldn't be surprised if that is the case but I never actually tried to measure that.On the other hand if the charge circuit are isolated from reverse current, It should be OK. The less expensive chargers may not be as 'isolated' as one might want.

 

[Daman858]

Battery Tender makes great products. They have one with two sets of leads that you can use for your dual batteries. Have one on my boat and on my diesel pickup. You can install the cables on your batteries and just pug the leads in when you want to charge. Eliminates the clamps. you can leave them on all winter without worry of overcharging.