View Full Version : Batteries and Chargers~Questions

08-11-2008, 11:33 AM
Most of the units we have had in the past have been vacation or weekender units.
I am not sure what class I would put my new unit (used to us) in but it appears to be nicer anyway.
Currently our MH has two typical 12 volts batteries for the house use.
It appears to me that the tray was designed for bigger batteries.
I am not sure what advantage the bigger batteries would bring me over what I have. We will boon dock from time to time and I know how to manage my battery power.
We have a MagneTek 7445 converter/charger and it apparently has a timer circuit to detect how long it's been plugged into shore power to lower the charge rate to the batteries.
Is this charger worth anything and the investment to bigger batteries?
And how much longer would say t-105 batteries last in the same application?
I have heard these types of batteries will outlast the box store 12 volt types.

08-11-2008, 05:59 PM
Have you ever been here...


This is part 1 of 2, part 2 is more about chargers, inverters and such.

08-11-2008, 08:43 PM
Yes, I had seen that one just today.
And I have now learned a lot about the different types of chargers too.
I am surprised that many are below what I paid to replace a converter many years ago if you shop them.
I am not sure the extra cost of the AGMs are worth it to me. My battery holder is fully vented.
I am thinking some Trojan batteries might be in line for us when these cheap auto store marine batteries give out though.
Now to decide if I want to use the 6 volts in series or parallel a couple of the 12 volts.
A lot of folks seem awful happy with the T-105s.

08-12-2008, 08:23 AM
When I think about 2 x 6 volts vs 2 x 12 volts I think about failure mode.

If one 6 v fails you're in the dark. Not likely, as golf cart batteries are well made to be subjected to abuse.

If one 12 v opens, you still got power. If it shorts, (not likely) you are in the dark and there may be smoke.

If you're gonna rip out the whole thing, I'd go 2 x 6 volts. In either case you want 2 of the same exact type, manufaturer and even lot to have your batteries evenly matched as possible.

08-12-2008, 09:02 AM
Well...When it comes to converter/chargers the Magnetek is an older unit (they have since been bought & sold, and the new company (Parallex) makes a much better product in my not very humble opinion) I would seriously consider replacement

As for larger batteries: Two considerations

1: Weight: The bigger battery (Save for Optima, which are a special case) the heavier the battery (If you look at optima you can see that they have a lot of air space, this makes them lighter for the same physical size factor, That is "Battery Group" plus you pay pay pay for all that air)

2: The heavier the battery the more power it can hold (AMP HOURS) (NO exceptions)

So bigger batteries hold more power = more run time without mains power or generator

Best battery choice depends on many things, including, of course, the size of the tray, but when it comes to watts (amp hours) per dollar, it is not impossible, but it is very hard to beat a pair of six volt golf car batteries in series, 232 amp hours (for the standard size, large or XL hold more) and reasonable price

They are, however, flooded wet cells and a bit taller than a 12 volt Group 27 (Same foot print however)

08-12-2008, 09:46 AM
Yes I am beginning to think that some Trojan T-105s are in order when these batteries give it up.
And I see lots of better converter/chargers out there than what I have. 3 stage, 4 stage. Lots of options. Although this converter in the unit now has maintained the batteries that are in it for close to a year now without a problem.
We have boon docked for days on end in the past and never had a problem in the managing power without running the genset.
I finally found the specs on the solar panel that charges the battery. It's only a 10 watt unit but it's better than nothing. I didn't even know the unit had one until I looked at the power management panel and noticed the light indicating that something was on and I noted it said "solar charging".

08-13-2008, 05:21 PM

Trojan t-105 batterys are good but I think you might have a little better luck with the Interstate 220 I think that's what they are I have six of them, when we get back I am going to add the 2 solar panels I bought from AM Solar in Oregon. As it is right now I can go for two weeks with out charging the house batterys, and that with just a 10 watt panel. I wonder how long I will be able to go with 2 100 watt panels. After "She Who Must be Obeyed" goes back to work from summer vacation I am going to add 2 more panels.:radio:
Should beable to talk forever then. As it is I can use my 706 and my Bi-Pap machine, the tv and all the lights, I also have what are refered to a scene lights [the kind that are mounted on an ambulance] on the side of the RV they will light up about 75 yards.
73 de w6pea