Adding a second battery

[tjw0099]

Hey folks,

I am looking at adding a second battery to my travel trailer.

My wife and I don't do any boon docking yet, but I want to be able to have additional power should we lose power at one of the State parks or at one of the Membership parks.

I am seriously thinking about purchasing a portable solar panel power supply. Go Power and Zamp Solar have a nice portable unit for under $600.

I do have a couple of questions.

1. Has anyone added a second battery? If so, did you series or parallel connect it? How did you do the circuit connect?

2. Has anyone added solar to recharge the battery? If so, what brand and how is it working for you?

Any and all input will be greatly appreciated.

Tom

[_1nobby]

#1nobby wrote:

I know what he said.

But as you so schooled me a year ago on batteries...I did a little research of my own.

And it is NOT suggested to pair OLD with NEW.

Being condescending is a one way street, it appears.

[time2roll]

If you mix an old and new battery (both in good shape) it will work fine. Although if the older battery should last another 3 to 5 years you should expect the new battery to have the same life. Still saves money today and should serve well. Both are not going to suddenly just fold under in one season.

Replace both together when they are done. RV could even be traded before that happens.

[rbpru]

If you have a decent old battery and you put a new battery with it, the older battery will often steal some energy from the newer battery.

However, the end result will still be an increase in the total amount of available power. Perhaps not quite as much as from two new batteries but if it is enough to do the job, what's difference does it make.

[westend]

SoundGuy wrote:

westend wrote:
Trying to match a used battery with a new one is a fool's errand.

I'll have to remind my friend who did just this last year, with no issues at all, what a fool he is - according to you. :R

Lol, don't take it too personal, it's just Physics.:B

[CavemanCharlie]

theoldwizard1 wrote:

#1nobby wrote:
I upgraded to 2 - 6V batteries....with battery boxes and a shut off switch. Gives me 220 amp hours, I boon dock all the time and go 4-5 days no problem.

Yep ! 2 6V golf cart batteries are the best bang for the buck.

Me too. But, I only watch the TV for a few hours a day. But, I do have a small 12 volt fan I run all night long for the noise.

If I am running the furnace then I need to keep a eye on battery power. The furnace is a power hog.

[_1nobby]

SoundGuy wrote:

time2roll wrote:
Second similar 12v battery in parallel is fine for what you are talking about.

#1nobby wrote:
Either way...he needs to buy 2 batteries.

Might as well be 6V.

The OP said in his original post - o

"I am looking at adding a second battery to my travel trailer".

As long his first battery is in good shape there's no reason he can't simply add a second similar one - no need to replace it with a pair of 6 volt jugs.

I know what he said.

But as you so schooled me a year ago on batteries...I did a little research of my own.

And it is NOT suggested to pair OLD with NEW.

[Boon_Docker]

If I were you I would remind your friend ASAP. :B

[SoundGuy]

westend wrote:
Trying to match a used battery with a new one is a fool's errand.

I'll have to remind my friend who did just this last year, with no issues at all, what a fool he is - according to you. :R

[rbpru]

It might be interesting to see how long you can go on one battery.

The DW and I can go for 2 1/2 days on our battery. Usually 1 day is enough. On those rare occasions when I know we will be out longer, I carry a spare battery and switch it out.

Unless we run the furnace motor, we lose more power to the phantom loads then to the LED lights and water pump.

Twice we have lost power while camping, once for 3 hours due to some CG upgrades and the second time for 11 hours because of a wind storm.

Because we come from a tent and canoe background, the biggest problem is me whining because we do not have a microwave. 🙂

Boone docking takes a bit of serious thought to do properly for more than a day or two. It is more than just adding a battery and solar charger.
Two of the "primitive" campgrounds we looked at in Michigan's UP only allowed 4 hours of generator run time and that was in only half the park. They looked like great places to camp but were definitely intended for primitive camping.

[westend]

SoundGuy wrote:

time2roll wrote:
Second similar 12v battery in parallel is fine for what you are talking about.

#1nobby wrote:
Either way...he needs to buy 2 batteries.

Might as well be 6V.

The OP said in his original post -

"I am looking at adding a second battery to my travel trailer".

As long his first battery is in good shape there's no reason he can't simply add a second similar one - no need to replace it with a pair of 6 volt jugs.

No, there is no "need" but the OP would be wiser by just doing that or, choosing two new 12V batteries wired in parallel. Trying to match a used battery with a new one is a fool's errand. The two batteries will never be electrically similar, in that, the original battery has had it's capacity changed by use.

About the solar charging: You can buy from Home Depot, a 100W solar panel and a Grape solar charge controller for under $150 US.

[SoundGuy]

jorn wrote:
I would never pair an existing battery with a new battery. If you want two batteries (to double your AH rating) then buy an identical set at the same time, and always treat them as that pair.

Ideally yes, but in this case the OP already has one 12 volt battery of unknown age & condition - because he never detailed this information. :R However, if this existing 12 volt battery is relatively recent and has been properly maintained he could easily parallel it to a second new one without the world coming to an end and it's certainly FAR less costly than investing in a new pair of batteries. A friend of mine did exactly this, adding a second G24 to his existing year old G24, and both batteries are serving the purpose just fine. However, this point may be moot now that the OP has decided he's going to go ahead and buy a pair of GC-2s.

[tjw0099]

Yes, that was a momentary lapse. Glad it happened in print and not in action!!

Tom

[SoundGuy]

tjw0099 wrote:
Yes, I will purchase 2 6V batteries at the same time.

And hook them up in series, not parallel as you previously said. 😉

[tjw0099]

jorn,

Yes, I will purchase 2 6V batteries at the same time.

Tom