Replacing Interstate 12 volts with 2 Fullriver 6 volt AGM's Question

[hoagy_007]

Hi All,

I know there is quite a bit of information on replacing the factory 12 volt interstate's with 2 6 volts in a series. I get the connection between the new batteries to make them a series. I have 2 positive and 2 negatives coming from the 2018 30' Flying Cloud (attached drawing). And my question is do I connect the 2 positive so the free positive with ground cable and the 2 negatives to the free negative? Don't want to damage the new batteries.

[hoagy_007]

Image associated with question.

[SilverHouseDreams]

1 pair likely goes to the normal trailer 12V system and the other pair is probably dedicated for your inverter, though I am not remotely an expert on how they do things in the larger FCs. You would likely need to connect them both to the open negative/positive battery terminals.

[hoagy_007]

Thanks, that is what I'm going to connect up this evening. I spoke to the dealer that uses Fullriver (not that brand is all that important) and will connect up the positive to positive and negatives to negatives. Makes sense!

[waninae39]

IMHO, go LiON

smaller, lighter and more usable capacity.

over the battery lifetime the Capex and Opex is lower

[zapper]

Originally Posted by hoagy_007

Hi All,

I know there is quite a bit of information on replacing the factory 12 volt interstate's with 2 6 volts in a series. I get the connection between the new batteries to make them a series. I have 2 positive and 2 negatives coming from the 2018 30' Flying Cloud (attached drawing). And my question is do I connect the 2 positive so the free positive with ground cable and the 2 negatives to the free negative? Don't want to damage the new batteries.

I plan to do the same conversion on my 2017 30' FC. Suggest you take a photo of existing wiring system in the bat. box as is, before you upgrade so you can reference what was positive and negative before. I noticed that some black color coded wires actually go to the positive battery pole rather than the negative. Go figure.

[Vantair]

Coincidence after much AGM battery and size searching did the PD4655vl (per Randy) retrofit and this weekend this “exact series battery upgrade”.
2) Fullriver DC220-6 (6volt 220ah group 27 AGM) 71lbs ea. 2 yr warranty and 7 yr adjusted.

Also, because NO PRE 2017 BATTERY BOX EXTENSION MOD NEEDED for these 2) group 27 220ah bad boys!

These particular batteries height to top of flat terminal are a slick 8.9” tall 12volt factory Interstates are 9.5” (will be adding Fullrivers superior brass screw in AP stud terminals keeping original AS factory auto lug connections).

Excited to get some now serious boondocking as these AGMs are reported spec underrated (outperform printed specs) and can really take deep discharge abuse.

[Hein]

OP,

Presuming your original batteries were 12V then each pair of + and - cables were likely connected to each of the two batteries. My guess is that the two sets of cables come together at the other end. Easy enough to check that before proceeding.

Or, as stated, one set supplies trailer 12V and the other the inverter.

So now that you have two 6 volt batteries with the series jumper between them you essentially have one 12V battery. To carry the full capacity you need both sets of cables connected. So as you have stated; both + cables to the open + battery terminal and both - cables to the open - terminal. We often recommend a terminal fuse on the + battery connection. Bluesea makes them.

Check the other end first and be aware that although I understand electrics, I am not familiar with your particular AS.

Full River does make a 12V AGM in group 27 size. They are great batteries. We have them in our vans.

All the best,
Hein

[MIFC]

Originally Posted by Vantair

Coincidence after much AGM battery and size searching did the PD4655vl (per Randy) retrofit and this weekend this “exact series battery upgrade”.
2) Fullriver DC220-6 (6volt 220ah group 27 AGM) 71lbs ea. 2 yr warranty and 7 yr adjusted.

Also, because NO PRE 2017 BATTERY BOX EXTENSION MOD NEEDED for these 2) group 27 220ah bad boys!

These particular batteries height to top of flat terminal are a slick 8.9” tall 12volt factory Interstates are 9.5” (will be adding Fullrivers superior brass screw in AP stud terminals keeping original AS factory auto lug connections).

Excited to get some now serious boondocking as these AGMs are reported spec underrated (outperform printed specs) and can really take deep discharge abuse.

I know I’m bumping an old thread here but we are ready to pull the trigger on a pair of 220-6s as well. We have a 2014 vintage box so know we will need to do some work to make them fit.

My question is what are folks using for the terminals to accommodate both the car connection and the ring connections? Pictures would be great.

Thanks!

[steverino]

I cut off the old automotive style post clamps and crimped on ring connectors. This is an install of 2 banks of DC220-6, with one bank in the battery box, and the second under the couch.

[MIFC]

Thanks for the quick reply!

[Vantair]

On our 2005 didn’t want to “cut” any factory harness terminals keep flexibility to revert to standard lug batts in emergency or deal with reattaching something aftermarket even more bulky.

Therefore used Fullriver provided impressive “brass” screw in lugs terminals to maintain original harness use. POS post terminal being intentionally slightly larger than the NEG terminal to avoid reversing cables . Left tight but adequate space under lid using rubber covers to insulate.

[Vantair]

Fullriver brass posts. (Temp reuse of 2 factory black/red series jumpers until larger gauge black single jumper arrives).

[MIFC]

Thanks for your response and the pictures!

We’re finding that the use of the brass posts provided plus the screw on top of that to hold the ring terminals puts us at 10 1/4 inches high, and the depth of our box is only 10”. If we went all ring terminals we might be able to make it.

The trailer is still in storage; we’ll need to get it home in the next week or so and size it all up.

[gypsydad]

Originally Posted by hoagy_007

Attachment 313304


Image associated with question.

This is from another post currently going on but my help you. Forgive me if too basic...

In a series connection with the 6V's, you connect the - (negative terminal) from one battery, to the + (positive terminal) of the other battery, right? That's just one wire connecting the two batteries, (- to +) completing the circuit for 12V. Your + & - wires are connected appropriately, to the other terminal of each battery; one is -; the other is +. In order for the circuit to be complete supplying the 12V to the trailer, that single wire needs to connect both batteries. You should also consider a "kill switch" to disconnect power from the trailer when in storage.

Note in the picture of my batteries below although yours are different brand; the single red wire in upper left connects the - (negative) terminal from upper battery to disconnect switch terminal, which is attached to the + (positive) terminal. All positive wires from the AS go to the red "other" positive terminal upper right (red wires); all negative wires from the AS go to the "other" negative terminal, lower right (black wires) If you click on the picture twice, it will enlarge to see better.

[Vantair]

Originally Posted by Vantair

Fullriver brass posts. (Temp reuse of 2 factory black/red series jumpers until larger gauge black single jumper arrives).

For those interested (and fact we couldn't find any AS Fullriver 6V 220ah upgrade help on this), we did a complete YouTube video on the process keeping the smaller pre 2017 battery box intact with minimal modification.

Hope this helps others and a few other helpful AS tips and tricks not found on YouTube.

https://www.youtube.com/watch?v=0lORzPOlaoM

[rfequity]

i was wondering how much extra weight these 6 volt Fullriver batt would add to the tongue. i have a 25 FB and I don't want to increase any more weight up front.

[MIFC]

Fullriver 220-6 are 72 pounds each vs 46 for the SRM24 Interstates, so 52 pounds more for two. When lifting them into the box you need to make sure your opening is clear as you don’t want to have to hold on too long getting them in. Definitely a heavier battery.