Adding an extra house battery

[bmurph44]

I have a 2011 Jayco 31SS and because we always camp with no hookups I was thinking about adding another battery. There is no room where the current battery is located (that slide out drawer deal). I'm looking for some easy ideas.

[msturtz]

Originally Posted by bmurph44

I have a 2011 Jayco 31SS and because we always camp with no hookups I was thinking about adding another battery. There is no room where the current battery is located (that slide out drawer deal). I'm looking for some easy ideas.

I had the same issue. I installed a VMChargetank group 31 AGM battery under the bed. http://www.amazon.com/Vmaxtanks-Batt.../dp/B0042L7DZ8 I also swapped out the existing flooded house battery with the same battery. It fits in the factory slide out tray. I connected the new battery to the inverter negative post and to the factory input 12v power post. Oh yes I also have a separate fuse and battery disconnect. With this setup you need to turn off the 2nd disconnect prior to turning off the factory disconnect.

[bmurph44]

I was thinking the compartment right next to the house battery tray but I thought you was never suppose to install a battery in a closed space.

[Jmooney]

Correct. The battery will need a battery box with external vent

[225orourke]

can you not tie two together.. Keep it 12 volt not 24 volt .. Or is that to much to charge two batterys at the same time . ?????

[Jmooney]

They should go in parrellel and remain a 12 volt supply, just 2x the Amp hours.

Keep the connections as short as possible and as large a gauge wire possible.

NormAlly, you would establish 2 batteries at the same time, and matching in make and size.

They need to be the same AH size, unless you intend to operate and charge each battery independently , or the stronger of the two will be become parasitic to the smaller.

[Tinnys Rig]

That's great advice with emphasis on the parallel terminations. Otherwise you could do damage to your electriacal system if the fuse doesn't work.

[msturtz]

Originally Posted by bmurph44

I was thinking the compartment right next to the house battery tray but I thought you was never suppose to install a battery in a closed space.

You would need to install with a vent if it is a standard battery however if it is an AGM battery then it is not necessary. You can even install AGM batteries inside a passenger compartment. The compartment next to the battery tray could work however you would need to have a hold down and or battery tray because you want to ensure the battery does not move around.

[sdavies]

The original poster is correct, don't wire up (2) 12V batteries in series. However...

Batteries should not be wired in parallel because they will charge/discharge each other, which ultimately just consumes energy in both batteries. In addition, when one of the batteries fails (as they all do eventually) being wired in parallel will cause the other battery to fail.

If you want to increase capacity, place (2) 6V batteries in series. In order to end up with more total energy, the AH rating on the two 6V batts will need to total more than the AH rating on the single 12V.

I've been searching for the perfect physical size batteries to achieve this for my 31SS but have not yet found them. I"m probably going to put in the best Group 31 battery I can find or try to shoe-horn a Trojan T-1275 in the stock battery housing by removing the sliding tray.

[oldmanAZ]

Originally Posted by sdavies

The original poster is correct, don't wire up (2) 12V batteries in series. However...
snip...

Welcome to the forum.

[msturtz]

Originally Posted by 225orourke

can you not tie two together.. Keep it 12 volt not 24 volt .. Or is that to much to charge two batterys at the same time . ?????

I did tie them together. Two 12v batteries tied together in parallel*doubles the amp hours but not the voltage. Oem manufacturers do this all the time.

[msturtz]

Originally Posted by Jmooney

Correct. The battery will need a battery box with external vent

Not with AGM batteries. I work for a large Truck OEM and we do this all the time.

[msturtz]

Originally Posted by sdavies

The original poster is correct, don't wire up (2) 12V batteries in series. However...

Batteries should not be wired in parallel because they will charge/discharge each other, which ultimately just consumes energy in both batteries. In addition, when one of the batteries fails (as they all do eventually) being wired in parallel will cause the other battery to fail.

If you want to increase capacity, place (2) 6V batteries in series. In order to end up with more total energy, the AH rating on the two 6V batts will need to total more than the AH rating on the single 12V.

I've been searching for the perfect physical size batteries to achieve this for my 31SS but have not yet found them. I"m probably going to put in the best Group 31 battery I can find or try to shoe-horn a Trojan T-1275 in the stock battery housing by removing the sliding tray.

Sony but this is not correct information. We tie multiple batteries together all the time in parallel. The batteries should be the same age and type. The reason for this is the weaker battery will drag down the voltage faster than the strong battery shortening the life of the strong battery. That said in the commercial space we frequently just change the bad battery due to the cost.

[kjohn73]

There are thousands upon thousands of parallel battery hookups in every day use. It is common sense to use two batteries the same age and specs. Having said that, I have two different spec batteries in my old 97 gas Suburban, and they have never failed since they were installed probably ten years and 180,000 miles ago.

[Mustang65]

Originally Posted by kjohn73

I have two different spec batteries in my old 97 gas Suburban, and they have never failed since they were installed probably ten years and 180,000 miles ago.

There are a lot of new RV owners that think a battery is a battery and are not aware that there are a lot of different options and a lot listen to their dealers that most of the time have no clue as to what they are selling. When you are talking about your automotive batteries, it is like apples and oranges. The battery in my '65 Mustang lasted about 10 years. The automotive batteries have many thinner lead plates which allow for major discharge over a very short period of time and allow for a rapid recharge. Whereas deep cycle batteries have less plates and are MUCH thicker and release there power over a longer period of time and require a longer period of time to properly charge them. The reason for installing 2 batteries with the same Mfr/Date/Ah is because the internal resistance of each battery will be very close to that of the other.

When you put 2 batteries in parallel and they are not the same Mfr/Date/Ah they each have different charge characteristics (internal resistance) so you have 2 possible conditions you either overcharge or you under charge the battery bank, as the battery charger is not looking at an actual battery voltage but a average of the two batteries, the newer battery with a higher voltage will be lowered and the older battery's voltage will be increased. As soon as the charging stops the older battery will start to drop to its normal level while taking power from the newer battery. Unlike two matched batteries where there is very little resistance difference between the them.

You will still get 12VDC but your Ah over a period of time will be affected and eventually the newer battery will be drawn down to the characteristics of the older battery, and they will die together.

Don

[Kave&Lucky]

Here's a link to the thread where I installed an additional battery on our 2011 31ds
http://www.jaycoowners.com/forums/f3...tml#post213481

[Mustang65]

Originally Posted by Kave&Lucky

Here's a link to the thread where I installed an additional battery on our 2011 31ds
http://www.jaycoowners.com/forums/f3...tml#post213481

Nice job!!
Don

[wjfawb0]

Most every electrical substation in the country has 8 or 20 or 40 6V batteries (3 2V cells) in series to run the equipment in the event of a power outage. Most of them use flooded cell lead-calcium, lead-antimony, other lead batteries. Most telecom installations like cell towers have batteries too.


Pics and links to industrial batteries, racks, etc.
https://www.cdtechno.com/product/vla/kcr_kar.html


Much like lithium polymer batteries used in RC quadcopters and cars, the batteries need some amount of equalizing or balancing from time to time to extend their life.

[troutslayer]

Originally Posted by Kave&Lucky

Here's a link to the thread where I installed an additional battery on our 2011 31ds
http://www.jaycoowners.com/forums/f3...tml#post213481

I like it! No compartment venting required.

[Keljude]

I have a 2017 Greyhawk 29MV. We dry camp a lot and the one battery just doesn't hold enough charge, especially when running the heater. The compartment next to the battery tray is big enough for batteries. I'm planning on taking the compartment plastic shell out, having a metal tray system that slides out fabricated to go in it's place. I'll then replace the existing battery that's had severe use and add two of the same type, size, and date of manufacture. With three in parallel, I should have enough amps to last awhile. Any thoughts?? Should I go with the existing 27 series or upgrade to 31 series?