Hey all, just joined this site.. I am having problems keeping battery life in my travel trailer for more than one day. I have one sears die hard marine battery I have been using for about 2 years so its not that old.My water pump really drains the power fast. I want to connect another battery to double the time. Is it as simple as connecting the positive and negatives together to both batteries? My trailer is self contained 22 feet with all the usual. propane fridge, water pump, toilet with shower.Any help is appreciated.

Connect + to + and - to -. Connect the negative from the trailer to the negative on one battery and the positive from the trailer to the positive on the other battery to get even distribution of voltage.

facory wrote:Connect + to + and - to -. Connect the negative from the trailer to the negative on one battery and the positive from the trailer to the positive on the other battery to get even distribution of voltage.Correct...and good advice.Also probably best to start with 2 new fresh batteries. The system will only be as good as the weakest (old battery). The old batt. may draw down the new one that you add.

First things first. You need to take the battery out, recharge it fully and have it load tested. I suspect your current battery is toast due to ? Second you should never connect batteries of differeng ages together. The weak battery will discharge the good one. So be prepared to buy two batteries. NOT those over priced die hard dual function things either. Do some research for true deep cycle batteries. They may cost a bit more but with peoper care will last much longer. As for connecting? + to+ and - to - for the two 12 volt batteries. Connect the + from the trailer to + on one battery ans - from trailer to - of the other battery. You then have one giant 12 volt battery.

sprinter31 wrote:Hey all, just joined this site.. I am having problems keeping battery life in my travel trailer for more than one day.Agree with previous post. A fully charged, deep cycle battery will give you days of power - UNLESS, something is drawing on the battery constantly at a high amperage or a component is faulty resulting in a high amperage draw ( a binding water pump shaft, for instance).Teach

Yep, get your 2 year old tested. If it is good (and should be) look for a short (drain) on your TT. If your present battery is bad then just buy one new one and have another go at it. You can always get the 2nd one within a month or so of the first if you find you need it.

Wiring two batteries together | Good Sam Community

facory
Explorer
Sep 04, 2013
10 gauge
pianotuna
Nomad III
Sep 04, 2013
Hi,

Use the size that is "one up" from the OEM wire to the RV. No one ever had too much voltage drop by using larger than needed wire.

You can order cables online or you can go to a local battery shop and have them made to order.

Be sure to use a waxy anti corrosion spray after the connections are made.

Heelshock wrote:
Wire question: What gauge wire to connect the 2 batteries together?
Heelshock
Explorer
Sep 04, 2013
Wire question: What gauge wire to connect the 2 batteries together?

Also, I was looking at Wal-mart for cables that could be used to connect them, but I didn't see anything that would work. Can you point me in the direction, perhaps on Amazon or Camping World, of a prepackaged cable option to connect them.

Thanks.

pianotuna wrote:
This is what is balanced and best for twin twelve volt batteries.

As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?
pianotuna
Nomad III
Mar 24, 2013
Hi crcr,

Of course there are. But the ones with the little balls, which are not temperature compensated, are pretty much a joke. I'm sure you agree.
crcr
Explorer
Mar 24, 2013
pianotuna wrote:
Hi crcr,

A temperature compensated one like this 113: http://www.freasglass.com/battery.htm

crcr wrote:
So what kind of hydrometer is a "real hydrometer"?

There are lots and lots of hydrometers on the market with temperature compensation.
pianotuna
Nomad III
Mar 24, 2013
Hi crcr,

A temperature compensated one like this 113: http://www.freasglass.com/battery.htm

crcr wrote:
So what kind of hydrometer is a "real hydrometer"?
crcr
Explorer
Mar 24, 2013
SoCal traveler wrote:
Take out the guess work. Remove the battery, full charge it, let it sit for 24 hours under no use. Get a real hydrometer (not the one with the floating balls) and test each cell to see if you have short.
If just using the pump causes you to drain your battery, it sounds like a shorted cell.
Agreed with the info above, use new batteries not just one. The bad will leach off of the good.

Aloha ~ Todd

So what kind of hydrometer is a "real hydrometer"?
SoCal_traveler
Explorer
Mar 23, 2013
Take out the guess work. Remove the battery, full charge it, let it sit for 24 hours under no use. Get a real hydrometer (not the one with the floating balls) and test each cell to see if you have short.
If just using the pump causes you to drain your battery, it sounds like a shorted cell.
Agreed with the info above, use new batteries not just one. The bad will leach off of the good.

Aloha ~ Todd
Gau_8
Explorer
Mar 23, 2013
donn0128 wrote:
First things first. You need to take the battery out, recharge it fully and have it load tested. I suspect your current battery is toast due to ? Second you should never connect batteries of differeng ages together. The weak battery will discharge the good one. So be prepared to buy two batteries. NOT those over priced die hard dual function things either. Do some research for true deep cycle batteries. They may cost a bit more but with peoper care will last much longer. As for connecting? + to+ and - to - for the two 12 volt batteries. Connect the + from the trailer to + on one battery ans - from trailer to - of the other battery. You then have one giant 12 volt battery.

What he said!

if you have room, I would go,with two 6V golf cart batteries in series.
pianotuna
Nomad III
Mar 23, 2013
Hi Mike,

That depends on what converter you have. Sometimes an external charger would be better--and sometimes the converter.