Charging 6v batteries

[woodartist]

A Google search of "agm batttery charging" gives a lot of good info.

 

[Tom]

Don't believe everything you read on the internet. Most folks here provide information based on knowledge and experience.

 

[Ned]

On the other hand, this is an excellent reference on AGM batteries from Lifeline, one of the major manufacturers.  See page 2 of the manual for charging specifications.

 

[Gary RV_Wizard]

MagneTek 50amp Converter Charger Series 900 Model 950-2. The Owners Manual says that it is a "float type" charger and cannot overcharge a battery or batteries but there is nothing in it about AGM batteries.

If it is a 1993 vintage Magnetek, it most likely will overcharge batteries, despite what your manual says. They are notorious for that.  The 900 series is their top of the line, though, and it does have a float mode. Later models were better, but Magneteks in general are poor performers.

I am charging my AGMs with a standard Iota c/c without an AGM setting. No indication of any problem so far (two years). However, about the only effect would be a slightly shortened life span, so there is no way to tell.

 

[Woody]

On the other hand, this is an excellent reference on AGM batteries from Lifeline, one of the major manufacturers.? See page 2 of the manual for charging specifications.

That is the what I was referencing when I said "everything I have read". From page 2 it sounds like I have a single stage charger and that is not necessarily compatible with AGM batteries. I'm still going to try to get in touch with someone at Magnetek tomorrow but its beginning to sound like I probably need to replace my two wetcells with identical batteries.

Woody

 

[Gary RV_Wizard]

From page 2 it sounds like I have a single stage charger and that is not necessarily compatible with AGM batteries.

I'm not sure that "single stage" is an accurate description, since it does not use "stages" at all. It might be better to think of it as a tapered charge, where the final "float" is  a very low charge rate.  I would be more concerned that the 1993 Magnetek technoloigy did not control the charge rate very well under any circumstances, though the 900 series was the best of the lot. It was the cheaper 63xx series that was notorious for overcharging and the 73xx that replaced it was only a little better.

If you have not experienced overcharging on your current wet cells, I would not worry much about the AGMs either. On the other hand, if you don't mind checking the battery water periodically, 6V golf cart wet cells are a  whole lot cheaper and deliver just as much power and life span. Wet cell GC's should last 5-7 years with a decent charger.

 

[Gary RV_Wizard]

From page 2 it sounds like I have a single stage charger and that is not necessarily compatible with AGM batteries.

I'm not sure that "single stage" is an accurate description, since it does not use "stages" at all. It might be better to think of it as a tapered charge, where the final "float" is  a very low charge rate.  I would be more concerned that the 1993 Magnetek technoloigy did not control the charge rate very well under any circumstances, though the 900 series was the best of the lot. It was the cheaper 63xx series that was notorious for overcharging and the 73xx that replaced it was only a little better.

If you have not experienced overcharging on your current wet cells, I would not worry much about the AGMs either. On the other hand, if you don't mind checking the battery water periodically, 6V golf cart wet cells are a  whole lot cheaper and deliver just as much power and life span. Wet cell GC's should last 5-7 years with a decent charger.

 

[Woody]

Gary,

I have no way of knowing whether the charger was overcharging the batteries or not. I leave the motorhome plugged into house current (30 amp) whenever it is home and I do have to add distilled water every month. Sometimes almost a full gallon between the two batteries.

Woody

 

[Karl]

Woody,

Using almost a gallon for two batteries is a pretty good sign that you're boiling them by overcharging. Damage may already have been done, but only a true load test will tell. I suggest you get a decent hygrometer and charge them only when the s.g. indicates it's necessary, and stop when close to 85-90% charged - that is, until you get the 3-stage charger.

 

[John From Detroit]

So if I understand this right then all of the coach wiring is connected to the + terminal of one of the 6v batteries, a short wire connects the - of that battery to the + of the battery next to it, and then all of the ground wires are connected to the - of the second battery. Correct ??
I do have a Radio Shack multimeter but don't know how to use it yet. Guess I gotta get that little booklet out and read up on it.

Woody

I believe you have it.

Using radio shack multimeter,  Radio shack has two and a half kinds of two kinds, digital/analog, wires attacked, disconnectable I'll cover all

If the wires are not attached then there will be a jack marked either (-) or "Common" it gets the black lead

The jack marked (+) gets the red lead.

Again, ignore the two terminals that have the common wire, Set the meter to DC VOLTS and at least 15 (different meters different ranges) NOTE: if using an auto-ranging meter forget the range setting (Autoranging digital is the half kind)

Touch red to one multi-wire post and black to the other, Digital meter says +xxx the red is positive, -XXX it's ground

Analog meter deflects to the right red is positive left or no noticable deflection it's negative

In all but one case (analog deflecting right) reverse the wires to be sure no deflection is not a totally dead battery

 

[Gary RV_Wizard]

Sometimes almost a full gallon between the two batteries.

That's a lot of water for one month on two batteries. I would consider half that to be "normal" for two aged batteries on a 1993 vintage converter/charger. A new charger would probably reduce that to less than a pint and maybe only a few ounces if the batteries were relatively new.

 

[Jeff]

I use a half gallon a month on four batteries and consider that excessive compared to my last coach. At the suggestion of Xantrex I have just installed a new temp sensor to see if that is the reason for overcharging the batteries.

 

[Woody]

I thought I would give everyone an update on my house battery situation:
I found new 6v wetcells locally at a newly opened auto supply chain for $69.95 each on sale. The new batts weigh approximately 80 lbs., not the 40 lbs. listed in online websites. I had a devil of a time getting the old batts out since my hood opening is so small and they were so heavy but finally got them out of there. I enlisted the aid of my bodybuilder son to put the new ones in. He did it effortlessly which reminded me again of my age. ;D

The good news is that now the generator starts perfectly. Evidentlythe "starter problem" was just that the old batts weren't generating enough voltage to power the starter through the cable the length of the coach.

Woody

 

[John From Detroit]

I use a half gallon a month on four batteries and consider that excessive compared to my last coach. At the suggestion of Xantrex I have just instgalled a new temp sensor to see if that is the reason for overcharging the batteries.

My rig came with a Prograssive Dynamics 80 amp Intella Charger with Charge Wizard.  i keep it plugged in most all the time escept when going down the road or in Quartzsite (no plugs)

In the first YEAR, yes YEAR I used less than one gallon of water, Way less