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Open Roads Forum  >  Fifth-Wheels

 > Installing a second battery

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way2roll

Wilmington NC

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Posted: 10/16/20 08:49am Link  |  Quote  |  Print  |  Notify Moderator

Our FW is new. That said it's a 2020 and I am sure sat on the lot for a few months. It has one battery and it has solar so it keeps it topped off. I've never run it lower than 70%. As I think about boondocking, I was going to add another one in series. I had done this on previous MH's we had. But my question is really around the battery itself. Knowing Batts perform best when they are all the same. When I did my MH it was time to change them so when I added them they were all the same brand, type and age. Since my FW is pretty new, do I need to be overly concerned with the exact same brand and model battery? Any concerns about one being potentially a year older than the new one? And putting them in a series shouldn't change a thing as far as the solar/shore power charging them both right?

Thanks!


2020 F350 STX 6.7L Turbo Diesel
2020 FR Cedar Ridge Silverback 29rw

RoyF

Fayetteville Arkansas

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Posted: 10/16/20 09:01am Link  |  Quote  |  Print  |  Notify Moderator

If you have a 12-volt battery then you want the second battery to be in parallel because your systems require 12 volts only. Charge both batteries to the same voltage before connecting them in parallel. (If there were much difference in voltage then you would get a large current when they were first connected in parallel -- I don't know what might actually happen).

way2roll

Wilmington NC

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Posted: 10/16/20 09:05am Link  |  Quote  |  Print  |  Notify Moderator

RoyF wrote:

If you have a 12-volt battery then you want the second battery to be in parallel because your systems require 12 volts only. Charge both batteries to the same voltage before connecting them in parallel. (If there were much difference in voltage then you would get a large current when they were first connected in parallel -- I don't know what might actually happen).


I think I meant parallel - POS to POS, NEG to NEG. So I should bench charge them to the same Voltage. Makes sense.

Lwiddis

near Jawbone Canyon, CA

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Posted: 10/16/20 09:31am Link  |  Quote  |  Print  |  Notify Moderator

Just might be time to buy two 6s and not waste time and money on another 12. Solar watts should equal or exceed total batter amp hours.


Winnebago 2101DS TT & 2020 Chevy Silverado 1500 LTZ Z71, 300 watts solar-parallel & MPPT, Trojan T-125s. TALL pole for flags. Prefer USFS, COE, BLM, NPS, TVA, USF&WS, state & county camps. Bicyclist! 14 year Army vet - 11B40 then 11A - (MOS 1542 & 1560)


time2roll

Southern California

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Posted: 10/16/20 09:50am Link  |  Quote  |  Print  |  Notify Moderator

Get a second battery and go have some fun.
Not a huge issue really.


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Lwiddis

near Jawbone Canyon, CA

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Posted: 10/16/20 10:11am Link  |  Quote  |  Print  |  Notify Moderator

"As I think about boondocking..."

Do an energy survey (what you will use or what you want to use) and then times 1.5. That number will help you determine what battery amp hours you need. I use 70 or so amps per day so my number is 100. My T125 are 240 amps hours. Plenty and a reserve for boondocking.

KD4UPL

Swoope, VA

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Posted: 10/16/20 12:34pm Link  |  Quote  |  Print  |  Notify Moderator

If your battery is a year or less adding a similar one in parallel shouldn't cause any problems. If it were, say, 3 years old it would not play as well with the new one.
Ideally parallel batteries should be the same type (AGM or flooded) and size. Brand shouldn't be that big of a deal, particularly since all batteries are made by about 4 companies anyway.
In the future, when you need to replace all your batteries I would look at using 6 volt golf cart batteries in series.

pianotuna

Regina, SK, Canada

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Posted: 10/16/20 01:44pm Link  |  Quote  |  Print  |  Notify Moderator

Be sure to wire them in a balanced manner.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp hours of AGM in two battery banks 12 volt batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

Super_Dave

Harrisville, UT

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Posted: 10/16/20 03:56pm Link  |  Quote  |  Print  |  Notify Moderator

In my 5th wheel, I've got 2 batteries. I put the negative cable from the 5er on the negative post of battery 1 and the positive cable on the positive post of battery 2. The + to + and - to - from each battery is tied together. It works, someone can tell me if I'm screwing anything up.


Truck: 2006 Dodge 3500 Dually
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pianotuna

Regina, SK, Canada

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Posted: 10/16/20 10:48pm Link  |  Quote  |  Print  |  Notify Moderator

Super Dave,

The way you have them wired is correct, and can not be improved on.

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