Schumacher Battery Charger ?

[rhr1956]

I only have one battery and all it powers are lights.I have always used my cabin lights getting dim as an indicator of when my battery needs charging. My new (4 months old) AGM went from bright lights one evening to no lights the next night. I bought a Schumacher Marine Charger/Maintainer. It is supposed to automatically detect 6v or 12v batteries and then charge them accordingly. Upon first use, it wont go into 12v mode, only 6v. I called Schumacher and they said it will not charge a severely discharged battery in 12v mode. They said to go ahead and charge it in 6v mode. Once the battery gets enough volts in it, the charger will recognize it as a 12v battery and switch to the higher rate charge mode. Does this sound right?

[kd3pc]

although schumacher makes a marine charger, it really isn't....scrap the thing now...and buy a reputable marine charger ala Xantrex...

almost anything on this site or defender or BoatUS is a better charger than the one you have.

YMMV

[hellosailor]

What Schumacher said is right. A lot of "new" chargers including car alternators are being built so that they will not charge if the battery is under ~10 volts. This is to make sure a human troubleshoots the dead battery and system, making it less likely that someone will blow up a bad battery. Literally.

At least that's what they ALL claim.

An AGM shouldn't behave very differently from an old wet cell, if you went from light to black unexpectedly--look for a problem. Even deep cycle batteries don't like being discharged 100%, they can do that a limited number of times before they take damage.

[mitiempo]

The quote from Lifeline below was posted a while back by MaineSail. AGM batteries need to be treated properly or they die quickly. Buy a good charger like a Xantrex. Doesn't have to be a large one - they just introduced the 10 amp version of their TrueCharge2 charger and it sells for under 150 and will charge a dead battery. It is best not to take the battery to less than 50% state of charge otherwise its life will be very short as well.

[hellosailor]

I would suggest that LifeLine AGM shouldn't be confused with AGM in general.

LifeLine are possibly the only AGM maker who allow, much less recommend, equalizing their batteries and that difference should suggest that there is something very different about LifeLine's AGMs.

Possibly just the maker's attitude, possibly something very different about how they are made. I just got eight years out of a deep cycle AGM, never equalized. Per the maker's instructions.

[mitiempo]

But using them until the lights dim and then using a crappy charger won't do much for battery life - with AGM or any other type of battery. AGM batteries do require regular charging to 100%. If you are going to abuse batteries which is basically what the original poster is doing a flooded battery will handle it better and last longer.