AC battery charger working properly?

[tmcdonagh]

Hi Folks,

I purchased a fancy name brand (Sxxrs) 6/12v battery charger & Engine starter to maintain my deep cycle batteries through the winter months. It has a stated capability of charging the following battery types: standard 12v, 12v deep cycle, 12v AGM/Gel and 6v standard batteries. I am following the manufacturers directions for charging my Sears DieHard 27M Marine/RV deep cycle battery. When the charger is set to 2 amp trickle charge, 12 amp fast or 30 amp rapid, the voltage slowly rises through 14.5 volts and levels out at 15.5 volts over 30 minutes or so. The voltage never drops over time. I have confirmed this with a multimeter and my Balmar Smart gauge displays an overvoltage error. Is my charger operating properly?

Thanks,

Tom

[smac999]

Doesn't sound like it. You defiantly should not be at 15.5v

[a64pilot]

No, and if I had to guess, I'd guess it is in equalize mode for a Lifeline bank, they equalize at 15.5 V

[a64pilot]

Wait a minute, this is a plug into the wall, box charger, not a permanently installed marine charger?
Who knows what is normal for those things, they are not meant I don't think to stay plugged in, are not automatic, work with a simple timer etc

[tmcdonagh]

Originally Posted by a64pilot

Wait a minute, this is a plug into the wall, box charger, not a permanently installed marine charger?
Who knows what is normal for those things, they are not meant I don't think to stay plugged in, are not automatic, work with a simple timer etc

It is a garage based unit supposedly designed to charge all types of batteries and switch to maintain mode upon reaching 100% charge.

The unit may stuck in desulfation made. Unfortunately, it may have nuked one of my 12v deep cycle batteries. The other hold a voltage of 12.4. I have not had the battery load tested.

Thoughts?

Thanks,

Tom

[skipmac]

Hi Tom,

15.5 V is definitely too high and could easily fry a battery. I would at the very least keep a very close eye on water levels as that voltage may boil off the liquid.

Also, FYI the Diehard 12V marine/RV deep cycle battery is not totally a deep cycle battery. More like a heavy duty starting battery. If you have the room, next time you're buying batteries go for a pair of 6V golf cart batters like the Trojan T-105 or a similar from Penn or other reputable maker.

[Chuck Hawley]

My guess is that you have a poorly regulated charter that is either not transitioning into float mode, or it is not intended to be connected continuously.

However, there are worse things than to have a flooded battery connected to a relatively small unregulated charge source (say 2% of C). It's a pretty effective way to equalize a flooded battery by charging until the voltage ceases to rise for perhaps 15 minutes or so. When the rate of voltage increase equals zero, you've equalized your battery and you should reduce voltage to perhaps 13.3.

Cheers

Chuck

PS: I did this inadvertently with a 50W solar panel in the middle of the Pacific and my only battery was better thereafter.

[Scot McPherson]

Originally Posted by a64pilot

Wait a minute, this is a plug into the wall, box charger, not a permanently installed marine charger?
Who knows what is normal for those things, they are not meant I don't think to stay plugged in, are not automatic, work with a simple timer etc

the promarine prosport is a plug in the wall kind of charger. I cut the plug off and wired it directly into my panel giving it its own branch circuit so I can charge on shore power without having to plug it in. Just flip the switch. The thing works great, they are automatic, they are smart, they inspect the batteries and fault out if something is wrong, and they maintain the batteries automatically once the charging and holding cycles have been completed. I love mine.

[Dave22q]

15.5 sounds high. My AGM's peak at about 14 using smart charger but come down real fast to about 13.4. I think you have a charger problem.

[Stu Jackson]

Originally Posted by tmcdonagh

It is a garage based unit supposedly designed to charge all types of batteries and switch to maintain mode upon reaching 100% charge.

The unit may stuck in desulfation made. Unfortunately, it may have nuked one of my 12v deep cycle batteries. The other hold a voltage of 12.4. I have not had the battery load tested.

Thoughts?

Thanks,

Tom

Interestingly, this pretty much proves what many of us have been saying for a long time: "cheaping out" on a non-marine, essentially unregulated, charger ends up killing an expensive battery.

The $$ saved on the cheap charger now comes back to bite ya on the battery replacement.

A few extra bucks spent on a quality charger would have saved that money over and over again but not having to replace the battery and extending the life of the battery.

Lead a horse to water...

[tmcdonagh]

Originally Posted by Stu Jackson

Interestingly, this pretty much proves what many of us have been saying for a long time: "cheaping out" on a non-marine, essentially unregulated, charger ends up killing an expensive battery.

The $$ saved on the cheap charger now comes back to bite ya on the battery replacement.

A few extra bucks spent on a quality charger would have saved that money over and over again but not having to replace the battery and extending the life of the battery.

Lead a horse to water...

True true, i guess, but here I was going with a product supposedly designed specifically for the batteries they sell. Shame on me for being the trusting type. It was not a cheap model in terms of cash.
I be more careful to listen to the "experts" in the future.

[four winds]

tmcdonagh,

Can you share the model number of your charger with us?

[tmcdonagh]

The unit is the Sears Diehard Gold 6v/12v Battery Charger & Engine Starter Model Number 28.71225

Page 4 of Sears Automobile Battery Charger 28.71225 User Guide | ManualsOnline.com

[tmcdonagh]

Originally Posted by skipmac

Hi Tom,



15.5 V is definitely too high and could easily fry a battery. I would at the very least keep a very close eye on water levels as that voltage may boil off the liquid.



Also, FYI the Diehard 12V marine/RV deep cycle battery is not totally a deep cycle battery. More like a heavy duty starting battery. If you have the room, next time you're buying batteries go for a pair of 6V golf cart batters like the Trojan T-105 or a similar from Penn or other reputable maker.

Thanks for the tip on the sears battery. I used these in my backyard observatory to power my telescope mount and camera.
On my Tartan 30 I have just enough room for two group 27 Exide dual purpose batteries. One wired as house and the other as a starter for my Atomic 4. I am guessing they are close to due for replacement as I have owned Servus for 4 years and they were certainly not new at the time I bought her. The house battery does not accept charge like she used to.
I have a small removable Aurinco 18 Watt solar panel (RIP) with a charge controller for topping off and maintaining my batteries on the mooring during the week when I am required to make money to pay for my hobbies. With the winds predominantly from the SW, placing the panel on the cockpit hatch provides about 5-7 hours of direct non-shaded sun each day.
I would love to switch over to the T-105's but alas, my battery compartment is limited to the group 27 size and just barely unless I modify the space at great time and expense.
As I use Servus for day sailing and the occasional overnight, I should be good with the setup I have now. I may buy a true deep cycle group 27 battery for my house and stay with an exide dual for the starter. There are conflicting opinions on mixing battery types, but this topic requires more research.

[tmcdonagh]

Originally Posted by Stu Jackson

Interestingly, this pretty much proves what many of us have been saying for a long time: "cheaping out" on a non-marine, essentially unregulated, charger ends up killing an expensive battery.

The $$ saved on the cheap charger now comes back to bite ya on the battery replacement.

A few extra bucks spent on a quality charger would have saved that money over and over again but not having to replace the battery and extending the life of the battery.

Lead a horse to water...

A search of cruisers forum did not bring up any specific reviews for Marine grade chargers. In fact, there are a lot of conflicting reports on reliability out there. Any recommendations on where to find this information?

Tom