Battery choices...why?

[twh731]

We are getting our bearings on putting our 70 Safari together. It is pretty much stripped inside except for the bathroom. The wiring is supposedly new as well as the plumbing. The wiring looks like a rats nest to me. Anyway, we are going to have the wiring straightened out and we will need the batteries so that those can also be installed at that time. We have the urge to use solar panels installed on the roof in the near future. So, my question is what drives the decision to use one type / voltage battery over another? Why use 6v vs 12v? Why golf cart battery vs AGM or Lithium. I will need to make a decision soon on the batteries that we are going to be using and it will be one of the first big purchases for the TT. Thanks for your patience as we are very much newbies to putting together an elegant and functional AS. Tom

[cwf]

Howdy.. using 6 volt in series gets 12VDC. The 6 volts can have more 'power' stored and deliverable... than a single 12 volt battery.. even if you have 2 of them in parallel.

Each battery takes it's own level of storage and charge rate, even if 'identical' in design. If properly built, you can have very close / similar batteries... so, cost vs performance is your choice. Ask Lewster about the LIFELINE and solar solutions. You can't go wrong.

[BoldAdventure]

Originally Posted by twh731

Why golf cart battery vs AGM or Lithium.

Hi Tom,

Think you're a little confused here. So Golf Cart batteries tend to be 6V, they're usually larger than a 12V battery and feature more Amp Hours.

Golf Cart batteries are just 6V batteries, they're commonly found in "golf carts" - and they come in Lead Acid, AGM and Lithium varieties.

Just like your standard 12v batteries do. So the difference in 6V versus 12V is usually increased Amp hours. They're shaped a little differently, and usually weight more.

Where as one 12v group 24 would be 60 amp hours and one 6V would be 100 amp hours. (not exact, just an example) This is why running two 6V batteries in series to get 12V will always produce more amp hours than two 12V batteries.

Lead Acid batteries are the oldest type, they're probably the cheapest, and they perform ho hum.

AGM is Absorbant Glass Matt - no water in them, don't need to be vented, usually hold charge and can be discharged better than a lead acid battery. Not susceptible to vibration. Supposed to last longer, yada yada. More costly.

Lithium is amazing, where ever Lewster is he can tell you all about it, but better in every way, except on your wallet. $$$$$$

Hope that clears things up.

[Beach Bum]

Tom,

If your Safari is gutted you may want to think about looking at the whole power system including solar now. You have the opportunity to save significant labor time by doing it now rather than retrofitting later. Not to mention moving and configuring the equipment components to optimize system performance. Sorry couldn’t help my engineer self.

Back to your question on batteries. Before you decide on the batteries you should think about how long and how often you plan to boondock. Also an estimate of your AMP/HRS usage per day. The more power and the longer the boondocking stay will quickly slide you up the scale to more efficient but more costly batteries.
If you do not plan to replace your charger/converter buy batteries that closely match your chargers characteristics.

There is no one size fits all right answer. It depend or how you camp and your budget. The only universal thing most agree on is if you have a single stage charger get rid of it before buying new batteries. A single stage charger will significantly reduce any type batteries life.

[idroba]

Two main reasons for different batteries, capacity and cost.

If you are planning to boondock capacity is often very important. If you always or most always will be in parks with hookups, capacity is much less important.

A pair of Golf Cart size batteries, six volts in series, will give you 1/3 rd more capacity than two type 24 12 volt batteries in parallel, for about the same cost. (normal flooded cell batteries).

Normal flooded cell batteries are cheapest, AGM's are about double the cost, and Lithium are only just barely on the market now, and are at least double the cost of the AGM's. They also require special chargers, both regular and solar. Unless you have mega bucks, they are not worth considering at this point in time.

Some claim that AGM batteries last longer than flooded cell batteries, but that is usually because the flooded cell batteries are mistreated by lack of maintenance, poor chargers, and other factors under the user's control, but often ignored. When AGM's are put in, usually the chargers are upgraded which is one reason the batteries then last longer. In addition they need no periodic water addition. However, flooded cells with a proper 3 stage charging system need very little water, maybe check semi annually or even annually. I check water level annually and have proper charging systems on my flooded cell batteries. I changed out my golf cart type's in my '74 Argosy after about 9 years, so treated properly they can last a long time.

Battery selection is highly dependent on how you may use them, how willing you are to put the proper charging equipment in, and how diligent you will be in maintaining them. There is no one answer which fits all owners needs, especially if there is any $$ to be considered.

[twh731]

Thank you all so very much for the information. I just didn't know the differences in application. The lithium intrigued me but the newness, very narrow charging requirements, and the winter limitations for charging kind of knocked them out of contention, not to mention the price. It sounds like the AGM will be the way to go for us as we plan on boondocking quite a bit since we live minutes from some of the most beautiful mountain access in the US. Since we have a mostly clean slate to work with we are trying to get the electrical and the the LP systems done first. The plumbing has been roughed in with PEX already and looks like it is pretty nicely done...won't know until we "turn the water on". We really like the fact that we will have 50 gallons of fresh water when we go off into the boonies! So, in essence it looks like a couple of 6v AGM batteries is a good starting point for us. We will have the wiring, charger/inverter, and controller spec'd for the future solar panels. Thanks again for your expertise and advice. Tom

[Lance M]

Here is a link to some good battery information.

Deep Cycle Battery FAQ

[twh731]

Thanks for the link. That was very informative and interesting. Looks like the basic end user "industry standard" is the Lifeline series of battery from what I have been perusing on the forums. I'm leaning toward 2 6v Lifelines to begin with. Will add more if necessary, but 2 should get us going with our AS. Heavy but durable and a very useful life. Tom

[ole81]

This discussion of battery types is very informative, but my question is how will our 1981 Univolt system react to battery types other than the old wet cell?

[Lance M]

Originally Posted by ole81

This discussion of battery types is very informative, but my question is how will our 1981 Univolt system react to battery types other than the old wet cell?

It will ruin whatever battery you put in it, eventually. If you aren't going to be boondocking and plan to keep the univolt, just use a cheap FLA from Walmart.

Pretty much useless to have a high priced battery if you don't have a high quality converter charger.

[Glenritas]

1. get the Univolt out of your trailer, sell it or repurpose it for a bench top power supply .

2. Figure out the battery and charger you want .

3. get the charger now. BTW it will power your trailer without a battery.

4. Don't get the battery until your trailer is ready for the road. No sense in it sitting around while you finish the trailer.

[twh731]

That's a very good idea! I thought the batteries had to be in place to run the 12 volt system. I am starting with the basics here so every little bit helps. Heck I just found the big electrical cable in the back "trunk" after having the AS parked at our house for 3 days! Don't know if it's 50 or 30 Amp though. Will have to install a receptacle at the house to plug it in. Tom

[acstokes]

Twh731,
The important thing is whatever batteries you end up with keep them well maintained. This will vary some depending upon whether they're AGM or lead acid. As already recommended, a 3-4 stage converter or during the interim until you get one, a 3-4 stage charger, is necessary.
Your electrical system is very likely to be a 30 amp one. If you use a standalone charger, you can plug it directly into an extension cord. If you use an existing converter or install a new one, you can get a 30 amp to 20 amp adapter for your shore power cable to plug into. In either case, you won't be able to run high wattage appliances such as AC, microwave, coffee pot, etc., but you will be able to keep your batteries charged.



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[KJRitchie]

Make sure your converter/charger you decide can match the charging requirements of your batteries you choose.

Kelvin