Batteries: Final Word

[Siamese]

Here's a link to the best battery information I've found. The article is written by a marina owner on the East Coast who is a frequent poster on sailing forums. The demands a sailboat puts on it's batteries are very similar to those of an RV, but with the possibility of more dire consequences should the batteries fail.

I've been a sailboat owner much longer than I've been a travel trailer owner, and I've used the author's advice on various topics to save many thousands of dollars in maintenance on my sailboat. He is not associated with any manufacturer, has no axe to grind, and prepares these articles as a public service. I occasionally go to his site and send him twenty bucks.

"Batteries: Final Word" may sound like an overstatement. But, it ain't. Here's a good link to save to your favorites:

https://marinehowto.com/what-is-a-deep-cycle-battery/

P.S.
Perhaps the most compelling part of the article is where the author saws batteries open to show the plates in 6v batteries vs. so-called 12v deep cycle batteries.

[Screwby]

Very good read and makes me feel a lot better with my Duracell 6v battery bank. Although reading it I realized I didn’t in fact have a 215ah battery bank like I’ve always thought for some reason. It’s 430ah which makes me even happier. I wasn’t adding the amp hours from each set of 6v like I should have

[Siamese]

Originally Posted by Screwby

Very good read and makes me feel a lot better with my Duracell 6v battery bank. Although reading it I realized I didn’t in fact have a 215ah battery bank like I’ve always thought for some reason. It’s 430ah which makes me even happier. I wasn’t adding the amp hours from each set of 6v like I should have

Nothing like a little vindication.

Bang for the buck, hard to beat the Duracell (East Penn) 6v batteries. I take it you have two pairs, wired series/parallel. Nice setup for off-grid. I'm running one pair of the Duracell 6v which serves us well, as we're seldom off-grid more than one or two nights.

[Screwby]

Originally Posted by Siamese

Nothing like a little vindication.

Bang for the buck, hard to beat the Duracell (East Penn) 6v batteries. I take it you have two pairs, wired series/parallel. Nice setup for off-grid. I'm running one pair of the Duracell 6v which serves us well, as we're seldom off-grid more than one or two nights.

Yes, two sets of 6v with a 400w Renogy solar kit on the roof feeding them. Just added a 100w solar suitcase with a built in waterproof smart controller from them as well to the mix. Figure if we tucked back into the trees and the roof panels were too shaded I would grab the suitcase and set it in the sun and let it earn its keep. They said the two systems won’t fight each other but one will be dominant. Whichever is pulling the most wattage and amps in will take over and the other controller will sit idle just like it does on shore power.
I may have gone a bit overkill on the setup but I wanted full self sufficiency or as close to it as possible.

[RoyBraddy]

Yup… Two 6VDC batteries in series will give you 12VDC you want but will only give you the AH's of one battery...


google image

To double the AH's rating you have hook two of these in PARALLEL...

Something like this perhaps...

Roy's image

Roy Ken

[Mustang65]

Granted, true deep cycle batteries are the way to go.. most us understood that. But in RVing when the majority (I would say more than 95%, based on my interaction with RVers, probably closer to 99%) the battery is not on their priority list. It just sits in a black box and when the interior lights no long work, it is time to replace it... and they then ask if they really need to replace it.

Most do not even check their battery's water level. They have no clue as to what the lowest allowable voltage is (50% rule - 12.2VDC) in order to get the most life out of their battery nor do they care. If the heater fan is running very slow or the lights do not come on any more, it is time to charge the battery.

Then we have RVers that read all about the (2) 6volt batteries are the way to go. So, they go out and spend the bucks for them and they do not monitor them either.

Maybe what is needed is a battery monitoring system that:
- Gives you the TRUE battery voltage
- Gives you the TRUE battery temperature (not that RVers really care)
- The water level of the battery(s).
- Audio that warns you that you have 1 hour of 12Volt service left before the system is automatically shut down, with no bypass allowed.
- A user rating bar graph that rates the RVer's usage by Good, Average, POOR.

Without any battery system interaction (monitoring system) the majority of RVers just do not care much about batteries, or even think about them. What is $100 every year, or having to monitor the battery's life, they will choose the $100.

My 2 Trojan T145's are on their last year. The Ah's have really dropped this year. 7 years is in my opinion a very good battery life. I really think that the 250 Watt SOLAR system, helped me get to 7 years. Why, I did not have to worry about charging my batteries, it also lets me know what the current battery status is. I never let the battery voltage drop below 12.2VDC, hardly ever dropped to 12.4VDC. I just set my iPhone to remind me to check my water level, which usually needed only a small amount of water. Also, having the SOLAR system Equalize the battery system (15.2Volts) based on usage, which was usually 3 times a year, helped keep the plates in better shape.

So, TRUE DEEP CYCLE batteries may be better, but in RVing, based on how RVers care for their batteries, it will just be a BIGGER expense, that will happen every year or two. Not worth it to most RVers.

My Interstate 85Ah battery Ah test (based on my less than 15Amp loads)

When I replace the T145 batteries, I will do an Ah test on them to see what is left.

Don

[Siamese]

Originally Posted by Mustang65

Granted, true deep cycle batteries are the way to go.. most us understood that. But in RVing when the majority (I would say more than 95%, based on my interaction with RVers, probably closer to 99%) the battery is not on their priority list. It just sits in a black box and when the interior lights no long work, it is time to replace it... and they then ask if they really need to replace it.

Most do not even check their battery's water level. They have no clue as to what the lowest allowable voltage is (50% rule - 12.2VDC) in order to get the most life out of their battery nor do they care. If the heater fan is running very slow or the lights do not come on any more, it is time to charge the battery.

Then we have RVers that read all about the (2) 6volt batteries are the way to go. So, they go out and spend the bucks for them and they do not monitor them either.

Maybe what is needed is a battery monitoring system that:
- Gives you the TRUE battery voltage
- Gives you the TRUE battery temperature (not that RVers really care)
- The water level of the battery(s).
- Audio that warns you that you have 1 hour of 12Volt service left before the system is automatically shut down, with no bypass allowed.
- A user rating bar graph that rates the RVer's usage by Good, Average, POOR.

Without any battery system interaction (monitoring system) the majority of RVers just do not care much about batteries, or even think about them. What is $100 every year, or having to monitor the battery's life, they will choose the $100.

My 2 Trojan T145's are on their last year. The Ah's have really dropped this year. 7 years is in my opinion a very good battery life. I really think that the 250 Watt SOLAR system, helped me get to 7 years. Why, I did not have to worry about charging my batteries, it also lets me know what the current battery status is. I never let the battery voltage drop below 12.2VDC, hardly ever dropped to 12.4VDC. I just set my iPhone to remind me to check my water level, which usually needed only a small amount of water. Also, having the SOLAR system Equalize the battery system (15.2Volts) based on usage, which was usually 3 times a year, helped keep the plates in better shape.

So, TRUE DEEP CYCLE batteries may be better, but in RVing, based on how RVers care for their batteries, it will just be a BIGGER expense, that will happen every year or two. Not worth it to most RVers.

My Interstate 85Ah battery Ah test (based on my less than 15Amp loads)

When I replace the T145 batteries, I will do an Ah test on them to see what is left.

Don

That actually sounds kind of cynical. I've been on this forum for quite awhile now, and there seem to be a lot of people who are looking for knowledge in a palatable form. Suspension upgrades, safety enhancement, leak prevention, and hardly a week goes by that someone doesn't ask about batteries and whether a 6v setup might be the way to go. I'm willing to take their inquiry at face value, and posted an article that should get them where they want to be. I couldn't find an article for people that don't care.

[Xboaters]

What Siamese said!

[Vicr]

Originally Posted by Siamese

That actually sounds kind of cynical. I've been on this forum for quite awhile now, and there seem to be a lot of people who are looking for knowledge in a palatable form. Suspension upgrades, safety enhancement, leak prevention, and hardly a week goes by that someone doesn't ask about batteries and whether a 6v setup might be the way to go. I'm willing to take their inquiry at face value, and posted an article that should get them where they want to be. I couldn't find an article for people that don't care.

Thank you for the link to the article. As an electrician who can understand the technical aspects that are put forth in the article I found it very informing. I spent quite a lot of time on solar and sailing websites learning as much as I could about deep cycle batteries before adding my second battery bank. There are scores of people on these RV sites that say "6volt batteries are the best", "if the battery lists CCA it's not a true deep cycle battery" and then of course the people that think that any battery other than a Trojan is inferior. For my second battery bank I installed two 12v J185 AGM's which for the space I had and the capacity they have were the best choice for me. I compared 6v and 12v and the Fullriver J185's I selected were the right fit for me. I then researched chargers and bought the top shelf NOCO Genius with a 25a charging output which fulfilled my J185's charge rate of 20-55 amps. Fortunately for me I had the resources to invest in this system. With the right research anyone can purchase an optimum system which matches their budget. More people need to read this article before posting their "knowledgeable" answers on the RV forums.

[Screwby]

I don’t thing Mustang was being cynical. He’s always there when someone asks for help with solar or battery type issues. I get what he meant to say I think. This article in tandem with the proper knowledge that you also have to take care of the batteries is the total package. You can have the best batteries, the best solar, the best whatever, but if you don’t know how to use it or maintain it then it’s useless at some point. My system would be trashed by now had I not taken the time to learn to maintain it. I check each cells water on a schedule, no ifs ands or buts. I test the cells for correct acidity with an acid tester. I clean and spray protectant on any terminal that looks suspect. I hand test with a meter each battery on a schedule. I climb up and clean my panels with glass cleaner when I wash the TT. I make it a habit to go read the controllers display if I’m out in the yard doing something just so I know all is well.
Maybe I’m a bit OCD but I want to know if I need this thing to work it’s going to and if it doesn’t it wasn’t from neglect. So in Mustangs defense I think his point was, and I’ve seen it a lot full timing, is that we need the knowledge to use the gear as much as we need the gear itself. Too many RVrs barely seem to know how to change a fuse (not even kidding) let alone even know where their battery is and what kind they have. That leaves us geeks and diehards to help and teach them, if they care to learn, if possible.
Once again, awesome article and link!