New AGM batteries installation?

Scubawise · 12-14-2021, 07:33 PM

Hi will be at campsite with SP. Can I leave SP on for absorption refrigerator on electric only and change batteries?

Or turn of use store etc ?
Thanks old wise ones

Currently LFA going AGM group 31

DavidEM · 12-14-2021, 07:54 PM

I would turn off the use/store switch first. The coach should still have DC power from the converter if it is on shore power. Then you can swap out your batteries. Be careful of the live terminals.

If these are Group 31s then they will just barely fit into the Axis' step compartment. Install the first one, connect the negative jumper to its terminal and push it all the way to the right. The negative terminal will be hidden. Then tip in the second battery in on the left until it drops down on the bottom supports. Then reconnect the tie down straps and the other terminal connections.

I needed longer positive and negative jumpers for mine as the spacing was further than the G24 or 27s I removed.

The two pictures show the before and after batteries. The bottom one with the red arrow points to the negative cable to the coach's common negative terminal. The top one shows the new batteries with the longer jumpers. The negative jumper is curled back underneath and goes to the right hand battery negative teminal. The small blue wire is the solar controller output.

Good luck!

David

lwmcguire · 12-14-2021, 11:28 PM

I use food storage bags taped to terminals when working hot to avoid a spark or worse

Good luck, sure like my AGM's

dkoldman · 12-15-2021, 12:27 AM

I agree with all of the above, but will add I would disconnect everything including shore power. Your fridge can go 4 hours with no power and still be cold. Just keep the door shut.

Take extra precaution to avoid hitting metal and the post even with all of the power off.

Good luck

dkoldman · 12-15-2021, 12:30 AM

Quote:

Originally Posted by DavidEM

The two pictures show the before and after batteries. The bottom one with the red arrow points to the negative cable to the coach's common negative terminal. The top one shows the new batteries with the longer jumpers. The negative jumper is curled back underneath and goes to the right hand battery negative teminal. The small blue wire is the solar controller output.

David

Hey those are a nice pair of Non Dual Purpose Purely True Non Automotive Post Deep Cycle AGM Batteries.

dkoldman · 12-15-2021, 12:51 AM

Quote:

Originally Posted by lwmcguire

Good luck, sure like my AGM's

I am with you here

I buy the most expensive batteries ever in my lifetime and they have single handedly resolved every battery complaint I had with my previous FLA; so I am thinking I dun good; but there are some that seem convinced I paid that money for nothing because they are the same as a Deep Cycle FLA

ducksface · 12-15-2021, 01:00 AM

So many(not me. We have empty bins and empty cabinets)
Are so worried about space.

So many(not me. We have a very lightly loaded 24.1 with about 3,000lbs to spare)
Are so worried about weight.

Aren't lithium half the weight, no bigger, for almost twice the usable 'lectric?

This seems like a benefit that needs weighed....

Scubawise · 12-15-2021, 12:22 PM

Quote:

Originally Posted by DavidEM

I would turn off the use/store switch first. The coach should still have DC power from the converter if it is on shore power. Then you can swap out your batteries. Be careful of the live terminals.

If these are Group 31s then they will just barely fit into the Axis' step compartment. Install the first one, connect the negative jumper to its terminal and push it all the way to the right. The negative terminal will be hidden. Then tip in the second battery in on the left until it drops down on the bottom supports. Then reconnect the tie down straps and the other terminal connections.

I needed longer positive and negative jumpers for mine as the spacing was further than the G24 or 27s I removed.

The two pictures show the before and after batteries. The bottom one with the red arrow points to the negative cable to the coach's common negative terminal. The top one shows the new batteries with the longer jumpers. The negative jumper is curled back underneath and goes to the right hand battery negative teminal. The small blue wire is the solar controller output.

Good luck!

David

Thx I have FLA group 31 in now so vmax agm group 31 should fit. I saw rv tech do what you suggested..push right battery in first

Scubawise · 12-15-2021, 12:23 PM

Quote:

Originally Posted by lwmcguire

I use food storage bags taped to terminals when working hot to avoid a spark or worse

Good luck, sure like my AGM's

Good idea will do

Scubawise · 12-15-2021, 12:23 PM

Quote:

Originally Posted by dkoldman

I agree with all of the above, but will add I would disconnect everything including shore power. Your fridge can go 4 hours with no power and still be cold. Just keep the door shut.

Take extra precaution to avoid hitting metal and the post even with all of the power off.

Good luck

Will do appreciate

Scubawise · 12-15-2021, 12:25 PM

Quote:

Originally Posted by ducksface

So many(not me. We have empty bins and empty cabinets)
Are so worried about space.

So many(not me. We have a very lightly loaded 24.1 with about 3,000lbs to spare)
Are so worried about weight.

Aren't lithium half the weight, no bigger, for almost twice the usable 'lectric?

This seems like a benefit that needs weighed....

How true!

gnach · 12-15-2021, 06:38 PM

DavidEM- thanks for the photos, that's really helpful.
Okay, now that you've got the max sized AGM, which are sealed and don't off-gas, why wouldn't you close off the compartment from underneath (maybe, simply with sheet metal) and insulate it with 2" poly foam? That would eliminate a significant source of heat/cold and road noise.

Scubawise · 12-22-2021, 07:29 PM

Quote:

Originally Posted by DavidEM

I would turn off the use/store switch first. The coach should still have DC power from the converter if it is on shore power. Then you can swap out your batteries. Be careful of the live terminals.

If these are Group 31s then they will just barely fit into the Axis' step compartment. Install the first one, connect the negative jumper to its terminal and push it all the way to the right. The negative terminal will be hidden. Then tip in the second battery in on the left until it drops down on the bottom supports. Then reconnect the tie down straps and the other terminal connections.

I needed longer positive and negative jumpers for mine as the spacing was further than the G24 or 27s I removed.

The two pictures show the before and after batteries. The bottom one with the red arrow points to the negative cable to the coach's common negative terminal. The top one shows the new batteries with the longer jumpers. The negative jumper is curled back underneath and goes to the right hand battery negative teminal. The small blue wire is the solar controller output.

Good luck!

David

Thanks just followed your info and added vmax group 31 125 AH

Scubawise · 12-23-2021, 01:31 AM

Question installed vmax 125 ah group 31 ..5 hours ago ..shows 13.5 on control panel.

Is that OK or should I see these numbers ?

dkoldman · 12-23-2021, 02:48 AM

Quote:

Originally Posted by Scubawise

Question installed vmax 125 ah group 31 ..5 hours ago ..shows 13.5 on control panel.

Is that OK or should I see these numbers ?

1st that sounds about right.

2nd the actual number you see on control panel is a function on how smart the controller is to understand actual battery voltage versus current charge rate. If you wish to be precise check your converter manual and see what voltage rates it sends during certain conditions and get out a voltmeter to prove your controller is doing what it says.

Congrats on your vMax tanks. Let the controller do it job to charge the batteries, let the solar do it's job to top off the batteries. For your agms when you are at 12.9vdc you are at 100% SOC when you hit 12.4vdc you are at 50%. You should go a full day with the normal stuff.

You have only one job and that is to NEVER let the batteries go below 12.4vdc. If you sniff 12.4vdc within a day, you are doing something you are not telling, or there is something you are missing that is running

**16ACE27** · 12-23-2021, 03:08 AM

Quote:

Originally Posted by Scubawise

Question installed vmax 125 ah group 31 ..5 hours ago ..shows 13.5 on control panel.

Is that OK or should I see these numbers ?

How did you measure 13.5?

Charger has to be removed for at least 1/2 hour to see the true resting voltage.

It's a lead-acid chemistry battery - not much different than a FLA.

lwmcguir · 12-23-2021, 03:18 AM

I set my Magnum per the attached data sheet

In the 3 years the T105 bank has been in service voltage has dropped lower than target due to generator quiet time when without pedestal svc

Fortunately the batteries still are performing very close to where they started

I did set the final charge at 14.6 based on VOM readings at the batteries

Good luck and enjoy the extra power

lwmcguir · 12-23-2021, 03:21 AM

I charge at 14.1 to 14.6
Attachment wouldn't load

dkoldman · 12-23-2021, 03:55 AM

Quote:

Originally Posted by lwmcguir

I charge at 14.1 to 14.6
Attachment wouldn't load

I am attaching mine, it is all automatic charge wizard. 13.6vdc is normal and 14.4 vdc is in Boost mode while 13.2vdc in storage mode, every day while in storage in automatically boost for about 15 min to help condition the batteries. I never have to touch anything.

This is why I told Scuba the 13.5 is about right depending on state of his charger, I think he has intelligent program model as well in his 2020?

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