I am wanting to replace all 3 house batteries, but I am not sure what to look for, size and spec. wise. Can I get some recommendations so as I will know what to look for?
Thanks, Mike
Now this is a loaded question that should get a lot of replies and opinions and one that is difficult to answer without knowing what you currently have for batteries, chargers, solar and your usage. Do you do a lot of dry camping, or are you plugged into power most of the time and what are your power requirements.
The easiest thing to do is replace the batteries with what you already have IF they have given you good service. As long as they are deep cycle batteries that is. Batteries are a large expense so it is better to make a informed purchase.
There is no battery that will give better service than a six volt deep cycle wet cell battery with filler caps, as long as it is properly maintained, that's why they are used on golf carts. However that involves re-wiring the battery bank in a series parallel configuration. If you have the room and the incentive go for it. If I had room that is what I would do.
If you stay with the 8Ds you must make absolutely certain that you get deep cycle batteries. Most 8D wet cells with the filler caps are starting batteries and are rated in cranking amps (CA) and cold cranking amps (CCA). Not what you want for a house battery. Make sure that the house batteries are rated in Amp Hours. There are some 8Ds that are classified as a combination starting/deep cycle battery, I would stay away from them.
If you switch from wet cells with filler caps to AGMs you will have to change the battery charging parameters of your charge controllers. You will also have to make certain that your alternator is set to provide the lower voltage that an AGM needs, or remove the house batteries from the alternator charging circuit.
Don't even consider Gel cells.
Hope I haven't muddied up the waters too much.
Roland
You may want to read this blog. It is long but a very good read about batteries, charging and solar. I will re read it a couple times to absorb all the info The RV Battery Charging Puzzle « HandyBob's Blog (http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)
In our 1997 U295, we use three size 8D AGM batteries for the house. We use two size (group) 34 AGM batteries for the chassis batteries. The house batteries are designed to work better as deep cycle batteries. The chassis batteries are designed for starting. If replacing batteries, I would continue with the same configuration. The only change I might make would be to use three size 34 batteries for starting and modify the cables a bit. AGM batteries are clean, robust, and expensive.
I prefer to use AGM batteries for house and chassis so that charging profiles are the same. Our charging/maintenance systems are set for the AGM batteries.
Our house batteries are not a major brand. The chassis batteries are Optima. In the future, I would probably buy the appropriate AGM batteries from the local Parts Plus auto supply. I hope I don't need to make that decision for a while.
I use 3 Lifeline (Concourd) 8D AGM for house and 2 AGM for start. Yes, best to keep all the same for obvious reasons and adjusted the alternator too.
John H
Well, after reading HandyBob's article, it seems that the best setup would be six volt wet flooded batteries, and not sealed batteries. My starting batteries are new, and sealed AGM.
Can you operate these two types of batteries together?
Mike
Yes, you can use both types together. They have very similar charging profiles.
Six volt wet cells non sealed batteries will want to see 14.8 VDC (specific to the battery mfr but higher than AGMs) to fully charge, that voltage is too high for AGM's. They cannot use the same charging source.
Roland
FWIW
Note that the footprint of many (most?) golf cart batteries allows you to put 3 of them in the space 1 8D uses.
A pair of (say) Trojan 105s (it is conceivable that the Sam's Club GCs are also adequate) gives you ~220 AHs, as does a single Lifeline 8D. Thus you can increase the size of your house bank by 50% without constructing a larger battery box.
I had a pair of Trojans in my Buffalo bus. They did the job very well with no issues. Lots of space between the plates and the bottom for the crud to collect without shorting the cell.
Elliott, what are they going for a Sam's Club? If I remember correctly, Sam's had a pretty good deal on 8Ds also.
Pierce
Elliot, I think you will find the Lifelines are at least 255ah. I am going from memory as I have not looked at mine yet.
Amos, I think you are somewhat right as I also remember Lifeline telling me that they can be set to charge from my inverter (it does not have a specific setting for AGM on this original Xantrx 2500) on the flooded battery setting as that is close to what they need without damaging them. I did that but do use the solar for all charging issues as that has been set up specifically for them.
John H
Here is what Deka says about their AGM batteries:
"AGM Battery Charging Considerations:
Ideal charging varies by application. Many common battery
chargers are not fully compatible with AGM batteries, however;
they will not ruin the battery if used a few times over the battery's
lifetime in a commercial application. Adversely, not all chargers
are really AGM compatible and can do significant damage to an
AGM battery. Large "wheeled chargers," found in many shops,
which exceed 15.4 volts must be avoided. In the rare occurrence
that an AGM battery needs to be charged outside of the
commercial vehicle's charging system, charging voltage
should be 13.8 –14.8 @ 77°F (25°C). Not to exceed 30 AMPS."
correct as that is about what I was told, so Amos is correct I would think as we do not have the shop chargers in our coaches.
John H
Make sure you don't use the equalizer mode on your Xantrex or solar controller or you cook and shorten the life of the AGM's.
Roland
I have 4 T145 6v wet cell batteries for my house needs.
They work well and are not expensive.
I saw 6v T 105 batteries at Costco for about $80 each recently.
wording in the lifeline book is,
Absorbtion---100f--14.04 77f 14.3 30f--15.10 volts
float--------- 100f--13.03 77f 13.3 30f--14.08 0f---14.76v
to recondition at 77 f---15.48 volts
Do these batteries emit significant corrosive fumes? Do they require added ventillation and acid level maintenance?
I haven't noticed any Oder. No spillage, I topped them off one time last year, but they were not really that low.
I have found them to be trouble free.
They have been in the coach for almost 3 years. I paid less than $100 each.
Mine were over 5 years old and worked well with frequent discharge until the inverter would quit from low voltage. Only occasionally had to add a small amount of water. Could never detect any smell.
Pierce
Vented wet cell batteries will produce hydrogen gas when charging. I don't know that there would be an odor but hydrogen is a bit explosive.
Roland
I thought so. This is the reason I'm not in love with these type batteries in enclosed compartments and next to my fuel tank.
Having a gasing battery near a starter will explode when the contactor closes and makes a nice arc, you need a shovel to gather ALL of the battery. :o
BTDT
Dave M
You only need the shovel if you can find all the parts. ^.^d
You can use golf cart type house batteries but venting them is a bear - have to put each on in a box with a vent hoses outside that will let the gas rise and escape. That's tough in one of these coaches especially getting the vent outside