Plugged in while stored

AGM batteries were a speciality battery designed for things that roll over or tilt a lot.

Their life expectancy is less than GC2 batteries. Less abuse resistance. Cost more. Their advantage is less leakage and no maintenance. Good for the step in the motorhome or under the bed. Superior to car/marine batteries. Inferior to GC2 batteries for rv’s. Very popular in cars and trucks now. Cheaper.

Today there are lithium batteries in the same price range. Since they are much better, for rv’s kind of no choice.

When manufacturers added substantial demands for power on rv’s the lithium makes sense.
 
When the time comes I think I'll just replace my FLAs with AGMs based on the KISS theorem. If we went back to a TT I'd definitely look closer at the alternatives.
 
When the time comes I think I'll just replace my FLAs with AGMs based on the KISS theorem. If we went back to a TT I'd definitely look closer at the alternatives.
only difference in Motorhome and TT is the proximity and connection to the alternator
just about everything else that uses power on the HOUSE side is the same

Motor home often uses more power so more capacity is the biggest reason to upgrade
simply re-work the alternator charging and the only difference you'll notice is that you can power stuff far longer

KISS will work the same for AGM or Lifepo4
your choice if you want to add more things like solar
or a huge inverter to power the whole campground

I kept my swap as simple as possible ... added solar and now don't even have to plug in to go camping
only restriction on camping is water and waste
 
only difference in Motorhome and TT is the proximity and connection to the alternator
And the built in 4.5Kw generator that negates all the justifications for a major battery system upgrade based on our current needs and usage. The switch to AGM will be for the convenience of not needing to check battery electrolyte levels, not for more power.
 
Motorhome persons I sort of believe think differently. They all have fancy built in generators. So, they sort of do not care about running out of power.

I do not like to park near them. Starting up their generators is unpleasant at 2 am in a crowded park. Not really a big deal. But, it does wake up the guard dog and the DW.

However many parks have banned generators or have special times to run them. Mostly out west.
 
Motorhome persons I sort of believe think differently. They all have fancy built in generators. So, they sort of do not care about running out of power.
Somewhat true...I also have solar. I manage all the available power sources together as a system, not individual parts.
I do not like to park near them. Starting up their generators is unpleasant at 2 am in a crowded park. Not really a big deal. But, it does wake up the guard dog and the DW.
I've been around some folks like that..with noisy, cheap, contractor grade, generators for their TT...or for running the home window A/C unit rigged in to a tent. And also some motorhomes as well. I don't like being parked near that type of "camper" either. I've found that the lack of consideration doesn't necessarily follow RV type.
 
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Not to become argumentative, however……
Let’s first assume for RVs, that there’s FLA, AGM, Lithium batteries.
If there’s another type to consider, please add it.

I find that most people that suggest alternative designed battery replacements for motorhomes, don’t own one themselves. They’re more times than not, owners of travel trailers or 5th wheels, wherein, their batteries and needs are different than the “house batteries” of a motorhome because if a very specific OEM difference.

Care to comment on that difference?
 
Care to comment on that difference?
Lots of differences that don't have anything to do with the demand on the battery. (We've owned both a tt and now van type class B+)

The main difference is ease of replacement.
You need to protect the alternator of a mh when you get LiOn which involves extra expense.
You need to have the room to install the LiOn (many batteries are in limited space under the stairs of mhs.)
Most people who by LiOn are 'boondockers' which can be difficult for some mhs (Our rig doesn't have a lot of ground clearance for backwoods or 'off grid' camping)

In addition,
Trailers require a working battery to operate the brakes on the tt.
Motorhomes don't have that requirement. They have two battery sources- the chassis and the 'house' batteries and if the chassis battery is dead, you're not going anywhere.

Personally, we loved camping in our tt, but health concerns meant that we needed a more self contained unit for camping. Hooking up became very difficult. The generator in the mh makes life much easier when traveling or when we have to camp without electricity.

But we're getting off topic.
 
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Motorhomes don't have that requirement. They have two battery sources- the chassis and the 'house' batteries and if the chassis battery is dead, you're not going anywhere

On newer Class C Forester and Sunseeker motorhomes, excluding the M-B Sprinter chassis, you can use your house batteries to "jump start" the chassis. There is a switch on the drivers seat that connects the house batteries for this purpose. I don't know if the Promaster chassis, or the F53 For chassis, offers that option.
 
On newer Class C Forester and Sunseeker motorhomes, excluding the M-B Sprinter chassis, you can use your house batteries to "jump start" the chassis. There is a switch on the drivers seat that connects the house batteries for this purpose. I don't know if the Promaster chassis, or the F53 For chassis, offers that option.
Exactly! And if someone with the absolute expertise to know for sure can confirm or deny……..

Having Lithium house batteries, would not fare well to be able to provide the initial amps needed for startup of the engine when that driver’s seat switch is activated.
Nor, would those same Lithium house batteries, do well to provide the startup amps needed for the onboard generators found on a lot of Class A and Class C motorhomes. Some of these generators are 3,500 and 4,000 and even 5,000 watts in size. A considerable demand on batteries for a short duration, compared to Lithium batteries which I believe are designed for long term duration with lower amp draw.
 
Exactly! And if someone with the absolute expertise to know for sure can confirm or deny……..

Having Lithium house batteries, would not fare well to be able to provide the initial amps needed for startup of the engine when that driver’s seat switch is activated.
Nor, would those same Lithium house batteries, do well to provide the startup amps needed for the onboard generators found on a lot of Class A and Class C motorhomes. Some of these generators are 3,500 and 4,000 and even 5,000 watts in size. A considerable demand on batteries for a short duration, compared to Lithium batteries which I believe are designed for long term duration with lower amp draw.
Good explanation. AGM and LA do have more starting power.

Our Promaster chassis came with an AGM battery for the chassis and a LA for the 'house.'
We do have a toggle switch on the dash that allows the batteries to be connected when pressed. That doesn't work for a 'dead' battery though. (Ask me how I know.) We've learned how our coach works and how to store it for minimum battery maintenance.

We keep a battery charger/maintainer on the chassis battery when in the storage garage and turn off the 'house' battery with the switch in the coach.

If the house battery is dead, that's easily replaced. The chassis battery is a bear to change and requires a tow or a mobile mechanic.
Even my KIA Soul came with an AGM battery for extra starting power when it shuts itself off at signal lights. (Not cheap though)
 
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I’m fortunate with our particular rig, based on a Ford E450 chassis.
1. We have two AGM batteries under the entrance steps for the house. No messy water maintenance necessary.
2. There’s a maintenance free battery under the hood for the chassis.

There’s a momentary switch on the base of the driver’s seat which when pressed, can bridge the batteries to help in either direction.

Even with the house battery switch in the OFF position, the 100 watt solar panel system still charges all the above mentioned batteries, alternating back and forth.

When on shore power, the “house” converter balance charges all the batteries.
Personally, I don’t understand why this isn’t the design for all motorhomes.

I don’t think Lithium would be the battery of choice in either scenario, because we need starting power capability from either system at different times.
Am I wrong?
 
I don’t think Lithium would be the battery of choice in either scenario, because we need starting power capability from either system at different times.
Am I wrong?

No, your Triton V-10, and my Godzilla V-8, need some some serious CCA that "most" lithium batteries can't begin to sustain. (Note: I say "most" in case there is that one exception.) And the last thing I need to do is to overheat a lithium battery trying to crank the engine.

So AGM is the way to go for my needs and usage. Now to start the search for the "Best" :eek:;)AGM battery...:LOL:
 
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if you have lithium house and want to use it to jump start a flat chassis battery
best you connect the two batteries and allow the house.... to charge the chassis for 20-30 minutes
then hopefully you can get the CCA you need into the flat chassis battery

GOOD deep cycle whether they are lead acid or lithium............... are never meant to start big motors
true deep cycles are built differently than starting batteries
"deep cycle" that will start a big motor are those marine Hybrid style , which are a compromise between the two styles

My boat had AGM house ... they would NOT start my motor
had to leave them connected until the motor battery got enough oomph

If I had a motor home I would use jumper cables in preference to trying to use the house battery
would be faster .... unless you already hooked up the TOAD
-----------------------------------------------

of course you can also
start generator and plug in a battery charger
have some solar on the chassis side to lessen the chance of flat starter battery
make sure you BIM is functioning properly and disconnecting the house and chassis at the approprate times.... did your chassis battery go flat because of a bad BIM and was drained by house systems?

or is the chassis battery just OLD and needs replacing

Always carry a set of jumper cables... not just for your RV but so you can help a fellow traveler
 
we love to boondock and Harvest Host camping.

I would buy the biggest lithium battery that would fit. Note Aussie guy’s suggestion. Screwing up and having a dead vehicle battery should be an uncommon event. As the commander, I check my batteries twice daily.

An $80 lithium jump starter would also work as well as jumper cables.

Using your generator would recharge the rv battery enough in an hour or two. A 200 amp bms should start a small generator. Our two batteries give us 400 amps for starting.
 
Our 2019 30DS FR3 stays plugged in year-round, while not in use. 5 years later batteries are still good and only topped up water once. They do not over charge or boil with the supplied charger/converter in the rear compartment.
 
If I had a motor home I would use jumper cables in preference to trying to use the house battery
would be faster .... unless you already hooked up the TOAD

Faster? No... I don't think anyone could even open the hood as fast as I can flip a switch on my seat base. It is that simple.

An $80 lithium jump starter would also work as well as jumper cables.

+1 and you get much more functionality. I carry a BatteryTender brand "jump pack" (See Here) in my Bronco so it would be available. And in the emergency kit I carry in my motorhomes is a set of jumper cables I could use in a last ditch effort.

In summary, there are no real advantages for me to go with lithium batteries based on cost, or performance, when you consider all the power resources I have available and my usage. There are the conversion issues, the listed work arounds, and costs that are in the disadvantage list. So AGM wins...converting to lithium batteries just for the sake having them is wasted time and money in my case.

I don't doubt that for other folks lithium may well be a better solution than AGM.
 
Agreed. And if the charger is doing its job correctly, one should not need to add water. If water is regularly needed, this is likely due to improper charging, i.e. overcharging, or extremely high current load demands causing some boil-off. Never hurts to check water levels. Might just save a battery.

Bob
 
Faster? No... I don't think anyone could even open the hood as fast as I can flip a switch on my seat base. It is that simple.


if the starter battery is truly real flat
holding the emergency combiner switch is not guaranteed to work straight away

you just may have to hold that switch for a long time....
plenty of posts where people use sticks or something to hold that switch down


my post was not meant to go say go get lithium
just that if you got lithium or even GC2 lead acids it may be easier to use a jumer cable than wait for the battery to get some charge

did forget about the little emergence battery, never had one as I always had jumpers
 

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