I broke my RV house batteries, now I need new ones...

[Cate&Rob]

In all these amp hour calculations, remember that lead/acid (flooded or AGM) batteries should not be discharged below 50% and take a very long charging time to get above 80% state of charge. Thus, if recharging your batteries by way of running a generator, you should size your regular battery usage to 30% of nameplate Ah. Deeper discharge and faster recharge is another benefit of lithium technology batteries.

Rob

[d2reid]

I talked with Dakota Battery today, they don't have any 12v AGM in stock and would have to order them. He does have a ton of 6v AGM's in stock, 190AH rating. $360 each. At least a week if I order something, which is ok, we aren't moving any time soon.

My wet cell batteries were rated at 232AH. Not liking this.

I could just go get the 6v batteries, they may be adequate. I could make them work. Probably won't be doing any boondocking this year, maybe not next.

But

Segue...

I like getting geeky about stuff. For the last 5 years we have gone to a ski resort for the winter, that means driving in snow. My F450 is about 3 years old and needed new tires, 19.5's, not a lot of choices. So researched and read reviews and pondered and fussed about tires. Finally decided on Michelin XDS tires, excellent in snow. Bought, got em on. They are noisy. Ok, I can live with that, provided that when I need all that noisy traction in snow it works, which it did, both times I was in deep snow. Figured I could get three winters out of them. DW informed me that we are not returning to our winter ski resort home, many reasons, but the important one is our son getting married in Orlando. Now I am going to have to put up with those noisy tires for a long time because our needs changed from what I expected.

A good lesson, what are my needs? While it's good to have a sound boondocking battery system I have to ask the question: "Will I need it?" Old Boy Scout here, I like being prepared. My point being, I prepared for an eventuality that hasn't manifested, perhaps I am overthinking the battery thing. Maybe I should just go get the 190AH 6v batteries and be done with it. But my geeky side says I need to look at better options.

Random thinking. Decision, I am overthinking this. I am going tomorrow to buy whatever batteries I can find to solve my immediate needs. 95% of the time a single deep cycle 12v battery will meet my needs. If I decide to get froggy and go boondocking I will revisit this. The changes in the last 2 years has really unnerved me, I will go with what is needed now.

[Scott'n'Wendy]

Over thinking stuff.....Reminds me of that old Mark Twain quote..."I've been through some terrible times in my life.....some of which actually happened"

[d2reid]

you should size your regular battery usage to 30% of nameplate Ah.

Deeper discharge and faster recharge is another benefit of lithium technology batteries.

Rob

It's pretty obvious that I don't have enough battery to truly boondock. That when I do I abuse my batteries. But at least I am aware of what I am doing and will pay the cost of not being diligent. As far as Lithium goes, it's obviously the better choice for RV batteries, except for the not charging when it's really cold. But like my tire decision I went with most likely to occur. That is, we won't be doing much boondocking, and we may do more winter camping.

So I decided to just maintain status quo, kind of. I upgraded to AGM.


232 to 190, bit of a drop. My Victron battery thingy says I am pulling 2.8A when I turn my converter off. 190 divided by 2.8 is around 67 hours, but you only get 30% of that (at best), so if my calculations are close then I should run the batteries down to around 11.7V in 8 hours. Fuzzy math.

I found out why my batteries where having charging problems.


The battery terminal connection was completely eaten by corrosion. I acknowledge that I am not the best at battery maintenance. But the last time I put water in the batteries (about 6 months) I cleaned all the corrosion off the terminals and connecters. So this went fast. I also rebuilt my battery area and cleaned it all up. I made the batteries easier to access so I can check on them once a month instead of twice a year.



I very nearly messed things up pretty badly. When I went to hook the new batteries up I forgot where the positive and negative cables connect and got them backwards. Fortunately for me when I to attach the cable it was a tight fit so I barely touched the cable to the positive post. that was exciting, my finger will heal pretty quickly. Made me stop and really look at what I was doing. Who would put red wires on the negative side of the power bus bar? Then again who would remove and replace electrical wires without paying really close attention to where they are supposed to go?

It was just quick short an not long enough to burn anything out. My Victron meter installation instructions is the source that saved me from myself. The bus thingy is attached to the negative side, says so in the instructions, after that I got negative and positive correct, all hooked up.

Thank you all for the support and information.

[TucsonJim]

Dallas,

Even though the wires were connected wrong for only a very short time, it is very likely that your reverse polarity fuses on your converter blew. If you have any problems charging your new batteries, that's the first place to look.

The nice thing about AGMs is that they require little to no maintenance.

Jim

[d2reid]

Dallas,

Even though the wires were connected wrong for only a very short time, it is very likely that your reverse polarity fuses on your converter blew. If you have any problems charging your new batteries, that's the first place to look.

The nice thing about AGMs is that they require little to no maintenance.

Jim

Thanks Jim.

No indication that charging is not normal, but I will certainly keep and eye on it. I like little to no maintenance. I will double check the charging, I will be back in there Monday. With the cable end corroded off I had to use the squish connection technique, you know, where you strip some wire bare and then use the other cable end to squish it against the post. That needs to be fixed.