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hpcbmw · 08-12-2014, 10:45 PM

I've got a pair of trojan 6v batteries, I think the 105s. I bought them at a discount about 4 years ago as "returns" (I think it was $129 total for both). I've seriously mistreated them - I used them for three summers hooked up to a 45w harbor freight solar panel system that never fully charged them (only got a few hours of full sun per day). Average when I arrived at my RV on a Sat morning they were usually about 12.4 v or less, and would go down to 11.9 sometimes with heavy usage of lights, fridge, stereo and heater.

In the first winter, I had my rv hooked up to 110v. I had a magnatek converter that apparently regularly overcharges batteries (I did keep the water levels full). The next couple of winters I just had the rv hooked up to 110v when I was using it on the weekends, and the last winter I had a timer that turned on the 110v for an hour a day for days I wasn't there.

I've just replaced my magnatek with a PD converter that should charge and float correctly.

In the meantime, I pulled the Trojan batteries. I did a specific gravity check and then hooked up my new Stanley 40amp charger. I fully charged the batteris (hooked together as one 12v battery), then ran the battery rejuvenation mode (took about 36 hours). The specific gravity before/after rejuvenation is as follows: battery 1: 1100/1275, 1125/1275, 1150/1275
battery 2: 1225/1275, 1225/1275, 1175/1125

Before and after rejuvenation, the battery only charges up to 12.6v. After rejuvenation, I hooked up a small 12v rv fan and ran it for 3 hours and this dropped voltage to 12.4.

It seems the specific gravity came back up to "good" on all but one cell. Does this mean that battery is shot? How good are these compared to new batterys?

Thanks for any info.

RV Wizard · 08-13-2014, 03:55 AM

Specific gravity will only tell you state of charge, not the capacity or overall condition. I would recommend you take the charged batteries to a dealer that can check the condition via a digital battery tester and go from there. Good luck and keep us posted.

94-Newmar · 08-13-2014, 03:56 AM

You can try equalizing them....
Battery Maintenance | Trojan Battery Company
(Scroll down the equalizing section)

OLYLEN · 08-13-2014, 08:40 AM

Let's see, you hired a 60 y/o man, worked him 7 days a week, didn't feed him much, for 20 years, now you decided to feed him good. Now you want him to be 40 and work like a 20 year old. Purchase some new batteries!

LEN

hpcbmw · 08-13-2014, 08:49 AM

Thanks Wizard and Newmar for the helpful replies. The Trojan website has some great info. I'll see if I can do the "equalization", I'm not sure how that compares to the battery charger "rejuvenation", but I suspect they are similar. I'll give it a try with an older batt charger, then take the battery to a local dealer for a test.

Olylen, If I had the cash to go out and buy new stuff whenever something was a little used, I'd be a very rich, and very wasteful, man.

These batteries will have to do for another year or two - if they aren't up to 100%, then I'll reduce my electrical demands to fit the battery power. At this point, the rv batteries are more a luxury then a necessity.

**TonyDi** · 08-13-2014, 09:05 AM

Getting the batteries tested is the only way to know for sure what their state is. Because of the age and how they have been treated I would not hold out hope for them

Kurmudgeon · 08-13-2014, 05:10 PM

I had a set of 4 Trojans that lasted 12 years, even though they were occasionally abused. The last few years I used them I could not get them charged above the low 12 volt range and it didn't take a lot to draw them down below 12. However, they were still doing what I needed them to do, which was run lights, the water pump, and the occasional fan. I saw no reason to replace them just to make the lights a little brighter and the water pump a little faster.

In your case it all comes down to convenience. If they're not doing what you need them to do, replace them. But if you can live with the way things are, use them until they fail. How much is it worth to you to have the lights a little brighter?

wa8yxm · 08-13-2014, 06:04 PM

Well the best answer above is "No way to tell without testing" (or translates to that)

However, since you kept them watered when you used ye old battery killer, Odds are they are in fairly good shape.. But that's odds.

On the other hand I once had an automotive battery, This puppy came with a LIFETIME warranty (As long as I owned the car) So as you can guess it was a first quality battery... The charging system was completly inspected when it was put in and found to be properly operating.

It was inspected again a week later when they repalced it.

And several YEARS later when they replaced it again.. I'd have to ask my brother when that was (His 2nd wedding rehearsal was the same day) That one lasted till the car died of a drug overdose. (Shuttle truck from a lcoal drug store chain rear ended me and ran over it) .

Kurmudgeon · 08-13-2014, 10:26 PM

Quote:

Originally Posted by wa8yxm

On the other hand I once had an automotive battery, This puppy came with a LIFETIME warranty (As long as I owned the car) So as you can guess it was a first quality battery

Where can I buy such a battery? Since I tend to keep my vehicles a long time, that would be a great deal for me.

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