RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
 

Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > GENERAL DISCUSSIONS > General Discussions about our Montanas
Click Here to Login

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-18-2020, 12:22 AM   #1
whutfles
Montana Fan
 
whutfles's Avatar
 
Join Date: Apr 2015
Location: Omaha
Posts: 247
M.O.C. #17319
AGM Batteries - Venting and Disconnect Switch

I am on my 2nd set of AGM batteries and like them. I got to wondering if they needed to be vented? So I googled "Do AGM batteries need to be vented"? I found an article by RV Nerds titled "Electrical Myths, Part 4 AGM Batteries Don't Need Venting" By Dave Nov 1, 2017.

The article explained how they do need to be vented because they can release hydrogen gas in an overcharge situation. Then they quoted numerous organizations and their rules on ventning. One was this:

RVIA
The Recreational Vehicle Industry Associationís Low-Voltage similarly requires venting for all battery locations, whether or not batteries are actually installed, and prohibits installation of other potentially spark-producing equipment in the same compartment (e.g. inverters, charge controllers, disconnect switches):

Now I have read on this Forum many accounts of owners suggesting installing a battery disconnect switch to avoid the arcing when disconnecting a terminal and to avoid the drain when in storage. So I installed a disconnect switch and yes it is in the same compartment as the battery. Is that paragraph above from the RVIA correct and still in effect? And what is the difference in having a disconnect switch in the same compartment or not having one and getting the almost always spark when you connect or reconnect the battery terminal?
__________________
Bill Hutfles
2010 Montana Mountaineer 326 RLT
2012 Dodge Ram 3500 dually, 60 gal tank, Ride Rite Air Springs w/guages & pump
whutfles is offline   Reply With Quote
Old 11-18-2020, 10:06 AM   #2
DQDick
Site Team
 
DQDick's Avatar
 
Join Date: Jun 2011
Location: Wilsey
Posts: 17,794
M.O.C. #11455
Since I'm not building my units to sell I guess I don't worry about what RVIA has to say. I do vent both my AGM batteries, but over the different rigs I've had charge controllers, inverters and battery disconnects have all been located up there somewhere. They all had some type of battery disconnect.
__________________
Dick, Joyce, Diego, Picatso and Gustav
2017 3720 RL, and 2013 HC 343RL
2017 3500 Dodge Maxi DRW 4X4, Pullrite Hitch, IS, Disk Brakes, 3rd AC, Winegard Traveler, Bathroom door mod, Dometic 320, couch for desk swap, etc.
DQDick is online now   Reply With Quote
Old 11-18-2020, 03:32 PM   #3
jcurtis934
Montana Master
 
Join Date: Sep 2013
Location: Pensacola (mail forward service)
Posts: 3,010
M.O.C. #13740
Most quality battery switches are non-arcing switches meant for use in the same compartment as lead acid batteries which do vent a lot of gas on occasion. Agm batteries were developed for use by the military in sensitive locations and can be mounted in any orientation. It would be a very rare circumstance for them to vent at all. I use two group 31 agm batteries mounted in battery trays bolted through the compartment floor and connections are covered and protected, but not vented. The factory cables have been replaced with marine grade two gauge cable using sealed marine grade tinned copper sealed lugs secured with a five ton hex crimper tool. The factory cable connections using cheap thin hand crimped automotive connectors were not to my standards.
__________________
2012 F350 6.7 L dually, 2013 3800RE with 6 pt leveling, Sumitomo 17.5" load range h tires, Samsung 18 cu ft residential fridge, 8k Morryde I.S. with disc brakes. Full timing since 2012.
jcurtis934 is offline   Reply With Quote
Old 11-19-2020, 07:20 AM   #4
GreG L.
Montana Fan
 
Join Date: Jun 2018
Location: Jacksonville
Posts: 266
M.O.C. #21993
How does a gel cell work?
A gel cell is a "recombinant" battery. This means that the oxygen that is normally produced on the positive plate in all lead-acid battery recombines with the hydrogen given off by the negative plate. The "recombination" of hydrogen and oxygen produces water (H2O), which replaces the moisture in the battery. Therefore, the battery is maintenance-free, as it never needs watering.

The oxygen is trapped in the cell by special pressurized sealing vents. It travels to the negative plate through tiny fissures or cracks in the gelled electrolyte.

The sealing vent is critical to the performance of the gel cell. The cell must maintain a positive internal pressure. Otherwise the recombination of the gasses will not take place, and the cell will dry out and not perform.

In addition, the valve must safely release any excess pressure that may be produced during overcharging. Otherwise, the cell would be irreparably damaged.

It's important to note that gel cell must never be opened. If opened, the cell loses its pressure, and the outside air will "poison" the plates and cause an imbalance that destroys the recombination chemistry.
__________________
2020 Montana 3561 Legacy, everything except paint.
2018 Silverado 3500 DRW, 50Gal Transfer Flow, Andersen hitch.
GreG L. is offline   Reply With Quote
Old 11-19-2020, 09:47 AM   #5
Creeker
Montana Fan
 
Join Date: Nov 2018
Location: Charleston
Posts: 330
M.O.C. #23094
I'm still a lead acid wet cell user. We dry camp as much or more than with hook-ups. I've installed disconnects, inverters, auxiliary chargers, battery monitors, transfer switches, etc... in the same compartments in every unit we've owned. In fact, some units came from factory with simply an open battery compartment to the entire basement area. I make sure our battery bank is vented top and bottom to the outside and never give it another thought.

I'll skip over AGM technology as I've never had the need, and go straight to Lithium's next time. Probably be about 6 years as I just loaded our Montana with 470AH of 6 Volters this spring.
__________________
2019 Montana HC 310RE
2010 Wildcat 29RLBS
2014 Ford F-350 Lariat 6.7
Creeker is offline   Reply With Quote
Old 11-20-2020, 05:08 PM   #6
Cat320
Montana Master
 
Join Date: May 2006
Location:
Posts: 1,455
M.O.C. #5751
AGMs have virtually no gassing under normal operating conditions: Unlike flooded cells, gel cells and AGMs are hermetically sealed and operate under pressure to recombine the oxygen and hydrogen produced during the charge process back into water.
Cat320 is offline   Reply With Quote
Old 11-20-2020, 05:32 PM   #7
beeje
Montana Master
 
beeje's Avatar
 
Join Date: Oct 2015
Location: westminster md
Posts: 2,127
M.O.C. #17894
We have had 4 battery's for 5 years now (2-6 volt and 2 12-volt wire together) with no venting what so ever and have never had any issues. The compartments in most if not all campers are FAR from air tight and are self venting IMHO
__________________
2018 Chevy 3500 LTZ Dually Diesel 4x4 CCLB
2011 Montana 3455 SA. 6 point level up. Disc brakes. Curt Q24 Hitch. 5 step glow steps
Progressive EMS. Valterra tank valves. Sailun G637 tires. ARP fridge control. All led lighting. Mor Ryde IS
beeje is offline   Reply With Quote
Old 11-20-2020, 08:43 PM   #8
mtlakejim
Gone Traveling
 
Join Date: Oct 2017
Location: Bee Branch
Posts: 2,620
M.O.C. #20693
I am with DQDick that it doesn't matter what RIVA says they only suggest code for the industry and are not an enforcement agency. We own our coaches and can do what we want within limits.


Likewise I will agree that our battery compartments are not airtight to begin with and as such should have more than enough venting.


Finally if you are opening up a compartment to flip a switch, I expect that will vent any gas buildup to the point it is below explosive limit real quick. I wouldn't put an open flame directly in the compartment trying to make the gas explode but really can't see the concern under normal operations.
mtlakejim is offline   Reply With Quote
Old 11-21-2020, 06:35 AM   #9
Jeff Myers
Montana Fan
 
Join Date: Jan 2020
Location: Hilliards
Posts: 148
M.O.C. #25636
how are the AGM batteries with freezing? Can they take it? or do they have to be tickled all winter?
__________________
2020 MHC 330RL
2017 F250 SRW 6.7 Powerstroke
Retired NC Programmer
Jeff Myers is offline   Reply With Quote
Old 11-21-2020, 07:23 AM   #10
Daryles
Montana Master
 
Daryles's Avatar
 
Join Date: May 2019
Location: Alton
Posts: 790
M.O.C. #24086
Glad I switched to lithium. No worries about hydrogen venting.
Just have to think about lithium batteries catching fire and exploding...
__________________
Daryl and Marianne,
2019 3130re 20th Anniversary Edition
2016 F350 Lariat
Daryles is offline   Reply With Quote
Old 11-21-2020, 07:27 AM   #11
beeje
Montana Master
 
beeje's Avatar
 
Join Date: Oct 2015
Location: westminster md
Posts: 2,127
M.O.C. #17894
Quote:
Originally Posted by Daryles View Post
Glad I switched to lithium. No worries about hydrogen venting.
Just have to think about lithium batteries catching fire and exploding...
Isn't that like going from the fuel to the fire.. I think I'll stick with the old school flooded batteries. Lol
beeje is offline   Reply With Quote
Old 11-21-2020, 07:30 AM   #12
jeffba
Montana Master
 
Join Date: Oct 2017
Location: Bastrop
Posts: 2,696
M.O.C. #20753
Quote:
Originally Posted by Jeff Myers View Post
how are the AGM batteries with freezing? Can they take it? or do they have to be tickled all winter?
Wives should be tickled not batteries

Looking at the chart here they show data down to -20 I doubt I will see -20 in central Texas
__________________
2019 20th Anniversary Edition 3701LK
B&W 20K for Ford OEM Puck
2018 Ford F-350 Lariat CCLB PSD DRW
Poke super lignum unum et diem
jeffba is offline   Reply With Quote
Old 11-21-2020, 08:15 AM   #13
Creeker
Montana Fan
 
Join Date: Nov 2018
Location: Charleston
Posts: 330
M.O.C. #23094
Trickle or Tickle? Too much of either can lead to expelling gas.
__________________
2019 Montana HC 310RE
2010 Wildcat 29RLBS
2014 Ford F-350 Lariat 6.7
Creeker is offline   Reply With Quote
Old 11-25-2020, 03:25 PM   #14
bcrvman
Montana Fan
 
Join Date: Jun 2020
Location: Qualicum Beach
Posts: 154
M.O.C. #26399
Quote:
Originally Posted by whutfles View Post
I am on my 2nd set of AGM batteries and like them. I got to wondering if they needed to be vented? So I googled "Do AGM batteries need to be vented"? I found an article by RV Nerds titled "Electrical Myths, Part 4 AGM Batteries Don't Need Venting" By Dave Nov 1, 2017.

The article explained how they do need to be vented because they can release hydrogen gas in an overcharge situation. Then they quoted numerous organizations and their rules on ventning. One was this:

RVIA
The Recreational Vehicle Industry Associationís Low-Voltage similarly requires venting for all battery locations, whether or not batteries are actually installed, and prohibits installation of other potentially spark-producing equipment in the same compartment (e.g. inverters, charge controllers, disconnect switches):

Now I have read on this Forum many accounts of owners suggesting installing a battery disconnect switch to avoid the arcing when disconnecting a terminal and to avoid the drain when in storage. So I installed a disconnect switch and yes it is in the same compartment as the battery. Is that paragraph above from the RVIA correct and still in effect? And what is the difference in having a disconnect switch in the same compartment or not having one and getting the almost always spark when you connect or reconnect the battery terminal?
Well that's just both hilarious and sad. My old flooded lead acid batteries were within inches of several large breakers for the house circuit and the hydraulics plus all the electrical stuff to operate the hydraulics. Yes the battery box was vented through the floor and to the outside front, but there was still a non zero probability explosive gas could escape. I have since replaced with Lithiuim so don't care but others might want to check closely.
__________________
2018 Keystone Montana 3811MS
2017 Ford F450 diesel dually
400AH Battle Born Lithium Batteries, 4x170 watt solar
3,000 watt hybrid inverter with 120A charger
bcrvman is offline   Reply With Quote
Old 11-25-2020, 03:26 PM   #15
bcrvman
Montana Fan
 
Join Date: Jun 2020
Location: Qualicum Beach
Posts: 154
M.O.C. #26399
Quote:
Originally Posted by beeje View Post
Isn't that like going from the fuel to the fire.. I think I'll stick with the old school flooded batteries. Lol
Those are a different kind of Lithium battery.
__________________
2018 Keystone Montana 3811MS
2017 Ford F450 diesel dually
400AH Battle Born Lithium Batteries, 4x170 watt solar
3,000 watt hybrid inverter with 120A charger
bcrvman is offline   Reply With Quote
Old 11-25-2020, 03:29 PM   #16
bcrvman
Montana Fan
 
Join Date: Jun 2020
Location: Qualicum Beach
Posts: 154
M.O.C. #26399
Quote:
Originally Posted by Daryles View Post
Glad I switched to lithium. No worries about hydrogen venting.
Just have to think about lithium batteries catching fire and exploding...
The Lithium batteries you have heard about catching fire are either Tesla or laptop/phone. They are different chemistry than the LiFePO4 in your RV. Even flooded lead acid have caught fire when overcharged to the point of boiling off all the water.
__________________
2018 Keystone Montana 3811MS
2017 Ford F450 diesel dually
400AH Battle Born Lithium Batteries, 4x170 watt solar
3,000 watt hybrid inverter with 120A charger
bcrvman is offline   Reply With Quote
Old 11-25-2020, 04:15 PM   #17
lightsout
Montana Fan
 
Join Date: Sep 2019
Location: lake stevens
Posts: 497
M.O.C. #24938
Quote:
Originally Posted by jeffba View Post
Wives should be tickled not batteries

Looking at the chart here they show data down to -20 I doubt I will see -20 in central Texas
Cold is not the issue with AGM, however heat is AGM batteries do not do well in very warm climates, you being in Texas you should consider reverting to wet cell.

Personally Wet is the way to go, venting is very easy and you can also add a automated watering system very easily. And AGM does not have near the life of a maintained flooded battery.

Lithium while a good solution they should be cooled in hot climates but the bigger issue is unless you plan to keep your RV for 15-20 years the cost is a loser. Owning a Tesla's for 6 years (on 3rd one) I have great appreciation for Lithium batteries but I also appreciate the safegards built into the Tesla to protect the batteries and their thermal management (both under load and while charging)
lightsout is offline   Reply With Quote
Old 11-29-2020, 10:46 PM   #18
jcurryii
Montana Fan
 
Join Date: Jun 2012
Location: somerville
Posts: 125
M.O.C. #12636
Sticking to my wet cell

My 2012 Monty has the original wet cell. Plan on replacing with another wet cell this spring just due to age. My unit stays plugged in all the time itís not on the road.
jcurryii is offline   Reply With Quote
Reply

Tags
disconnect switches

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 11:57 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
×