Adding another 12v battery

[doitdaily]

My stealth WA2812 is brand new and before the battery gets any real use I would like to add another 12v. If I bought an identical battery can I mount it next to the battery compartment and run the neg. to one battery the pos. to the other and parallel the other terminals without a problem? and will it make a big enough difference to make it worth it?
A friend of mine (who doesn't own a trailer but understands electrical) tells me I need a switch and this and blah blah blah...

[GreenImp]

There's pro's and con's to both with, and without a switch. Personally, I would want it parallel and no switch.

[doitdaily]

I only think of the pro's what are the con's?

[rana]

Yes you can... and yes.. it is worth it. It will double the amount of available amp hours. I would check the production date on your existing battery. If it's within the past 6 months, then you should have no problem adding an identical type and size to double your capacity.

Ideally, my first option would be to go back to the dealer and ask to switch your single with 2 new of the same age.

Switch wise.. I DO prefer a battery cutoff switch installed. That makes it possible to cut all power to your rig (even with everything off.. there is still a parasitic draw) between trips. Then again.. it's almost as easy to simply disconnect the negative cable from the battery bank. It's all the same difference.

I am also unaware of any "cons" to having a battery disconnect switch.

[GreenImp]

I was led to believe by the content of the first paragraph, that the friend mentioned in the second paragraph was referring to an A/B switch vs wiring the batteries directly in parallel. Not whether or not a battery disconnect switch should be used. If the friend was referring to a disconnect switch, then yes, I agree it is best to have...although I don't ever use mine since I'm plugged in to shore power about 360 days a year.

So the question is...which switch was your friend referring to? Do you already have a battery disconnect switch?

[Witch Doctor]

Originally Posted by doitdaily

My stealth WA2812 is brand new and before the battery gets any real use I would like to add another 12v. If I bought an identical battery can I mount it next to the battery compartment and run the neg. to one battery the pos. to the other and parallel the other terminals without a problem? and will it make a big enough difference to make it worth it?
A friend of mine (who doesn't own a trailer but understands electrical) tells me I need a switch and this and blah blah blah...

That is the first thing I did. I put the new battery on the opposite side of the front basement to equal out the weight. Had the wires made up at Napa. My disconnect will disconnect them both. Make sure you get right gage made up including the ground... PS: did not add a selector switch for batt #1 or #2 or all.

[Ken K.]

Originally Posted by doitdaily

My stealth WA2812 is brand new and before the battery gets any real use I would like to add another 12v. If I bought an identical battery can I mount it next to the battery compartment and run the neg. to one battery the pos. to the other and parallel the other terminals without a problem? and will it make a big enough difference to make it worth it?
A friend of mine (who doesn't own a trailer but understands electrical) tells me I need a switch and this and blah blah blah...

Originally Posted by gljurczyk

That is the first thing I did. I put the new battery on the opposite side of the front basement to equal out the weight. Had the wires made up at Napa. My disconnect will disconnect them both. Make sure you get right gage made up including the ground... PS: did not add a selector switch for batt #1 or #2 or all.

I also added a second battery to my new TT. I don't have a selector switch on the battery bank but I did install switch at the fuse box. This allows me to disconnect DC power supply to the system so that I could stop the parasitic drain of the batteries during storage and I made sure to isolate the charging system so that it was effected by the switch's position. This way whenever I get a whim to take off I know my batteries are full and ready to go! Also I get peace of mind knowing that nothing is powered up in my trailer while it's in storage.

[NCBBA11043]

On my previous TT, I installed a battery selector switch for several reasons. You can shutdown all power (note, the emergency brake switch was still wired directly to the primary battery). You can draw from one battery without having the surprise of depleting all battery power (happens a lot when the batteries get older). When one goes low, switch to the other and recharge the first. Think of it as a propane switch-over valve. My previous TT had a horrible battery charging system, so I would electrically remove it from the circuit and recharge with a "battery tender". If you stay connected to shore power for an extended period, you could overcharge the batteries, or at least, boil off the water.

[fanrgs]

Does your Stealth have an on-board generator? If so, I wouldn't bother with a second battery. If not, then yes, a second 12v battery connected in parallel is worth adding. The reason for paralleling the batteries is to prevent drawing them down by more than about 25% in a single day. Although deep-cycle batteries can be drawn down 50% or more, you should be able to extend the battery life by limiting the draw-down.

I did exactly that in my travel trailer and also converted the light fixtures to LED bulbs. That way we could dry camp/boondock for several days on our Alaska trip without being concerned about running out of power (we did not carry a generator and never needed one on that 3-month trip). On my new 5th wheel, I am currently replacing the 12v battery with two 6v golf cart batteries connected in series to provide even more AH capacity than similar-sized 12v batteries will supply (this trailer came with all LED light fixtures). I am also adding solar panels on the roof and a MPPT controller to keep the batteries charged when we are dry camping.

Both trailers came with a factory-installed cut-off switch. The one in the 5th wheel is right behind the battery case in the front basement.

[camaraderie]

@doit...
You CAN add a second identical battery with no problem AND there is no need for a selector switch. IMO...a better choice would be a true battery monitor so you know exactly where you stand at all time rather than running down one battery till it fails before switching over! And yes...Positive to positives and negatives to negatives is what you want to do. Suggest current COACH positive cable stay right where it is on battery #1...and that the COACH negative wire get moved to the negative on battery #2 to provide more balanced charging.

NOW...while you can do this...and it may be all you NEED to do...it might be better to get two REAL deep cycle batteries if you boondock a lot and want the best cycle life which could end up saving you money in the long run. If you typically plug in somewhere, the dual purpose battery usually provided from a dealer is fine...as is adding another one.

[Det107]

As you said you bought identical batteries so a switch is your choice. I had to put a switch in to my setup because I had two new Optima (blue top) troll batteries so I used them in my RV. with the original acid type battery. The two types of batteries can not be charged together, but by separating them I can use them and charge them independently until the original battery wears out and then I'll replace it with another deep cell type.

[Gleaner]

My dealer put two Interstate Rv Batteries in a well built bracket from their shop before the PDI.
I was real impressed, as I hadn't asked or even thought about it.
They said with 3 slides they on the V-Lite they just do it....no charge. SWEET!

We hooked up and left after the PDI.
A couple days later I took it to work so I could drop it at the campsite that night.
When I turned around in the garvel parking lot (freight trucks turn in the same lot every day, so it's not tiny) I pushed in my chrome bumper some.
My ecstasy was gone. I hadn't backed up.... just made a fairly tight circle.
I have a picture of the marks of said turn in the gravel that the shop foreman wanted text to him.
They then said I need to lengthen my shank.....
This had never happened before.......
We are in negotiation.


P.S. I still like the 2 batteries.

[contractor Rob]

It's totally worth having 2 batteries, they must be the same in every aspect. I run with 4-6 volt batteries, there's the same. Forget the switch, it's just another thing to do

[rana]

Originally Posted by GreenImp

I was led to believe by the content of the first paragraph, that the friend mentioned in the second paragraph was referring to an A/B switch vs wiring the batteries directly in parallel.

Gotcha. I just re-read it and it could read that way. In that event, I still prefer running them in parallel with a battery disconnect. They are inexpensive and oh so handy.

I can't think of any practical reason why you would to put your batteries on an A/B type setup. If anything.. you are overly complicating your power systems, doubling the amount of hands on monitoring needed, building in the increased likelihood of an over discharge situation (below 50%), and shortening the lifespan of your batteries with deeper charge cycles.

Not to mention the added fusing, blocking, and temp comp sensors (if applicable).

[rana]

Originally Posted by Det107

I had to put a switch in to my setup because I had two new Optima (blue top) troll batteries so I used them in my RV. with the original acid type battery. The two types of batteries can not be charged together

I stand corrected. In that situation, you would NEED to run them in an A/B setup.

[Jjs2000z]

Get two energizer 6 volt golf cart batteries. These can be purchased for $89 at Sam's club. And they will last a long time and the price is right.

Trust me do not get another 12 volt battery. You are wasting your money.

[Tom48]

On the issue of second battery, boy I was hooked by this issue.

First HECK YES. Two batteries is a minimum, unless you plan to spend most of your time on hook ups.

When I didn't know better, the dealer sold me a toy hauler with one battery and I learned that in a hour trip, it hardly charges and it takes hours to keep up if you use the generator to charge it.

Now flash forward, 14 year Even with all led lights, that frig has a small static draw to the low voltage system even on Propane and when I get cold at night I want to know that the heater fan will come on.

Having a generator is nice and we would not go without, but if you run a battery dead it takes a really long time to charge it with the Gen Set, so plan ahead and do not run them dead.

Battery Cut off YES, at least to cut off power to the coach. Every unit I have owned or helped out on has one, but it does not usually disconnect everything. Usually your emergency brake switch and your Tongue Jack go right to the battery, so if they have any leakage, there goes your battery. To that end, I would say, IF you install a cut off switch at the battery, be sure you either cut everything off or that you are satisfied with any possible leakage at the Tongue Jack or Emergency brake. Since it might not be a good idea to cut power to the emergency brakes, that might be a circuit to check and leave alone . It also looks like my generator is wired directly to the batteries and fused separate from the trailer so be aware of possible leakage there too if it sits long term.

We will not leave the trailer hooked up to shore power beyond the time it takes to chill the frig or empty it when we get home. We think it is a bad idea to leave the frig on all when not in use anyway. But the factory Charger/converter is, in my case and in many others I have seen, a crappy one size fits all with a low amperage flat voltage charge rate and none or poor long term maintainer circuits.

Here is what we did. Three Batteries and 200 watts of solar on the roof (easy job to install by the way) going through a good quality PWM charge controller with about three charge rate levels and a monthly cycle that knocks the sulfication off the plates. With the third battery I installed an isolation switch and disconnect it after we get in to camp. Because I installed a 2000 watt full sine wave inverter and now run everything we need including the Microwave, without a Generator until we want the A/C on, there is a chance of running the house dead. So I want the third battery as a back up. IF we get careless with the inverter, we are OK. I take that one out of the loop after we get in to camp and IF I manage to kill the other two, it is an easy flip of the switch to turn us back on and start the Gen Set. But, it has never happened and even watching Direct TV half the night with the heater coming on constantly, we have never burned the batteries below half charge according to the factory installed system monitor panel and never below 11.3 volts actual.

So in short Two or more batteries-the bigger and stronger, the better and add some SOLAR. The 200 watt system with upgraded controller, wires and connectors in hand were picked up for about $350 at the warehouse door of WindyNation.com in Ventura, CA.

Good luck.

[Tom48]

Oh and I missed the Golf Cart battery post. Yes two 6's usually nearly half again more than two #24s' and Golf Cart Batt's seem to possess better deep cycle qualities.

Oh and WindyNation.com ships ups for free, last time I looked.