Any Limits on Battery Size

mduchemin · 07-22-2021, 09:27 PM

I just purchased a 2018 16 foot Jayco Feahther and it only had one small battery, which wasn't very adequate for what we do. So, I decided to put two batteries in parallel (which is what I have always had), but the batteries I ended up getting were a fair bit larger than the stock battery. I believe they were Group 27, and the old one must be a Group 24 (I think that is the accurate way to describe them). Both of course are RV/Marine Deep Cycle. OK, my question is, other than weight, is there any reason why I can't use a larger battery than what has been on it. I have the room up front.

Bob K · 07-22-2021, 11:01 PM

No deal killers at all. Group size upgrades are common.

Only things I can think of are weight & space concerns, and the possibility of the onboard charger timing out in Bulk charge mode before it can fully recharge your deeply discharged batteries.

For example, My WFCO 8735 switches from Bulk to Absorption mode after 4 hours. I've heard of people with big battery banks flipping the converter circuit breaker off and then back on to reset that timer and put the charger back into Bulk charge mode.

Jagiven · 07-22-2021, 11:37 PM

Quote:

Originally Posted by Bob K

No deal killers at all. Group size upgrades are common.

Only things I can think of are weight & space concerns, and the possibility of the onboard charger timing out in Bulk charge mode before it can fully recharge your deeply discharged batteries.

For example, My WFCO 8735 switches from Bulk to Absorption mode after 4 hours. I've heard of people with big battery banks flipping the converter circuit breaker off and then back on to reset that timer and put the charger back into Bulk charge mode.
Attachment 73915

X2. Most cases on small TTs, tongue weight is a major issue. When boondocking I carry a second battery in the back of my TV. I made a jumper cable. When the spare battery is needed. I place it next to the TT. I disconnect the onboard battery, and connect my spare battery. Usually the only time we have needed the second battery is when it is cold and we want to run the furnace.

Pauls72 · 07-24-2021, 08:39 PM

I have 2 Group 27 Deep Cycle RV/Marine batteries and never had any issues.
When the trailer was brand new, I moved the one battery over and added a second in parallel.

Most of the camping we do is primitive (boon-docking) so we need the extra power at times.

Jay2504 · 07-26-2021, 03:56 AM

Pauls72, was there enough room on the tongue to fit both batteries and 2 boxes for them? If that is true, you are very lucky. I would love to see a picture of your set up. Jay.

mduchemin · 07-26-2021, 08:08 AM

This is a photo of the frame where my batteries sit. In the picture you see my existing Group 24 battery (around 11.5 inches wide) and the available space for two new batteries (old one to be discarded). The full width of the available area is 27.5 inches, and the two new batteries will take up 26 inches of that space. Most Group 27 boxes I found were much larger than necessary and too big to fit in this space, but since the batteries are exactly 13 inches wide, I found online and purchased a 13.5 inch battery box. Thanks for the reply.

mduchemin · 07-26-2021, 08:09 AM

See my post above

Jay2504 · 07-27-2021, 07:14 PM

I see that the rails for the battery boxes are on top of the A frame. Unfortunately most of us are stuck with the rails on the bottom of the A frame, taking away that last couple of inches that let you run 2 group 27 batteries. Jay.

Mikec557 · 07-27-2021, 08:01 PM

Quote:

Originally Posted by Jay2504

I see that the rails for the battery boxes are on top of the A frame. Unfortunately most of us are stuck with the rails on the bottom of the A frame, taking away that last couple of inches that let you run 2 group 27 batteries. Jay.

On my TT (different brand) my rails are mounted underneath as you described. There was room for two group 24s in the common Noco battery boxes, but not two group 27s. That's because the brainiacs on the assembly line mounted three 12v circuit breakers and the 7-pin junction box directly inline with the batteries. I was able to re-locate the circuit breakers. The 7-pin junction box was too much to tackle. But after some judicious carving on my two group 27 Noco battery boxes with a multi-tool, they shoehornded right in.

Carve off the carry handle on both "inside" ends of the main box. Then 69 the tops and carve a little off the inside ends of those two. That narrows the two boxes by about 3 inches.

Jay2504 · 07-28-2021, 09:29 PM

I’m glad you got it to work. Will a group 31 fit in those boxes? Jay

Mikec557 · 07-28-2021, 10:09 PM

Quote:

Originally Posted by Jay2504

I’m glad you got it to work. Will a group 31 fit in those boxes? Jay

Thanks. I don't think a 31 would fit in this particular box. I ordered two boxes that I had to return because they too big to fit the tongue. I think they were group 27&31 size boxes. These are 27 only and just barely fit.

Murff · 07-28-2021, 10:44 PM

For dual batteries, two six volt golf cart batteries have more storage than two Group 27. Then you can use this box:

https://www.ebay.com/itm/28298141402...d00ae13e7c8075

Murff

Jay2504 · 07-29-2021, 06:12 AM

Mikec557, can you please provide a link to where you got those 2 boxes? And if the link doesn’t have dimensions and it’s not too much trouble, could you pop off a lid and measure the width of the opening at the top? You may have solved a problem for me. Thanks in advance. Jay

TWP723 · 07-29-2021, 07:28 AM

We have billionaires competing for space. We can measure quasars for their brightness and age billions of light years away. We detect new galaxies on the norm. But we still can't make a 12V automotive/DC battery that weighs less than 50lbs.

mduchemin · 07-29-2021, 07:45 AM

TWP723 -- The peculiar thing to me is that basically every website I found that sold Group 27 battery boxes those boxes were significantly longer than the one I purchased (link below). Instead of being 13.5 inches long, like the one I ultimately purchased, they were 17 inches long, which was way to long to fit two where my batteries are located on the trailer frame. The Group 27 batteries I purchased from Les Schwab are exactly 13.25 inches long.

https://www.zoro.com/quickcable-batt...01/i/G5574068/

Mikec557 · 07-29-2021, 09:28 AM

Quote:

Originally Posted by TWP723

We have billionaires competing for space. We can measure quasars for their brightness and age billions of light years away. We detect new galaxies on the norm. But we still can't make a 12V automotive/DC battery that weighs less than 50lbs.

Yup, we did. We ditched the metal: lead, and went with lithium. I think mine are about 35lbs each.

Mikec557 · 07-29-2021, 09:31 AM

Quote:

Originally Posted by Murff

For dual batteries, two six volt golf cart batteries have more storage than two Group 27. Then you can use this box:

https://www.ebay.com/itm/28298141402...d00ae13e7c8075

Murff

I have two Battleborn lithium group 27s. 100Ah each. Love, love, love that I have about 200 usable amps. I kept them (and other equipment) when I sold our 5er. I had to make them fit on the tongue of the new TT.

Mikec557 · 07-29-2021, 09:32 AM

Quote:

Originally Posted by Jay2504

Mikec557, can you please provide a link to where you got those 2 boxes? And if the link doesn’t have dimensions and it’s not too much trouble, could you pop off a lid and measure the width of the opening at the top? You may have solved a problem for me. Thanks in advance. Jay

Will do. Give me an hour or so.

Mikec557 · 07-29-2021, 11:19 AM

Quote:

Originally Posted by Jay2504

Mikec557, can you please provide a link to where you got those 2 boxes? And if the link doesn’t have dimensions and it’s not too much trouble, could you pop off a lid and measure the width of the opening at the top? You may have solved a problem for me. Thanks in advance. Jay

Here you go. I measured mine, but I can only reach the top of the box to measure. Remember, these boxes taper smaller to the bottom.

My top measurement, which may not matter is
14-1/4 x 8-1/8.

The NOCO label reads, I think this is the bottom of the box dimension,
13-1/3 x 7-3/4

Because the tops over hang on every side, they are gargantuan.

On the boxes I carved off the entire carry handle at the center. On the lids I carved off about 1/2 of the overhang that's supposed to protect the battery cables at entry... if you had cables enter the short side. I don't. But I did have to also carve/create a tunnel on the short end so the battery cables for the parallel connection could cross straight over.

Here's a bunch of pics, trying to show you orientation and carvings..

https://www.amazon.com/gp/aw/d/B004W...b_b_asin_title

deepsea5 · 07-29-2021, 01:14 PM

Quote:

Originally Posted by Mikec557

Here you go. I measured mine, but I can only reach the top of the box to measure. Remember, these boxes taper smaller to the bottom.

My top measurement, which may not matter is
14-1/4 x 8-1/8.

The NOCO label reads, I think this is the bottom of the box dimension,
13-1/3 x 7-3/4

Because the tops over hang on every side, they are gargantuan.

On the boxes I carved off the entire carry handle at the center. On the lids I carved off about 1/2 of the overhang that's supposed to protect the battery cables at entry... if you had cables enter the short side. I don't. But I did have to also carve/create a tunnel on the short end so the battery cables for the parallel connection could cross straight over.

Here's a bunch of pics, trying to show you orientation and carvings..

https://www.amazon.com/gp/aw/d/B004W...b_b_asin_title

I now have battery envy...

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