How many Ahs do you really need?

[newmarokie]

I got an answer to the lead question to this one. I am going to be replacing the batteries on my coach. 2019 Duch Star 4018. I currently have 8 6v HB 210 Ah batteries in place. I have a MS2812 Magnum Inverter/charge. If I understand the math that is 420 Ah available (840x 50%). I am seriously considering one 280 Ah 12v SOK battery. Now before anyone pulls the arrows out, I think we are a little wierd. We have power in our storage facility and rarely boondock. When we do (at a motorcross track or rodeo facilities), there will be scores of trailers running generators through the night. We don't have any plans in the near or mid term to do any "real" boondocking like many on here seem to. If our mission changes or I determine that the one is completely inadequate, I can easily add one or possibly two of these same batteries. My 4018 is pretty heavy on the front end so If I can get away with the one, I can knock just short of 600# off my front end. Has anyone else tried this? If yes, how did it go?

 

[osuallen]

You do realize that going to lithium is not just a swap and go?

 

[Kevin D Pem]

Ah!!! I don't know. Depends on how many questions I am asked!

Seriously though really Depends on the load placed on them. And ditto to the above.

 

[newmarokie]

Allen,
As near as I can tell, the only additional equipment needed is a BIM. All the other changes are completed on the panel. So, if there is more, I am not aware. I asked yesterday and got very little info. The battery I am looking at has self contained heat and BMS

 

[Wemustrv]

BIM?

 

[Neal]

I got an answer to the lead question to this one. I am going to be replacing the batteries on my coach. 2019 Duch Star 4018. I currently have 8 6v HB 210 Ah batteries in place. I have a MS2812 Magnum Inverter/charge. If I understand the math that is 420 Ah available (840x 50%). I am seriously considering one 280 Ah 12v SOK battery. Now before anyone pulls the arrows out, I think we are a little wierd. We have power in our storage facility and rarely boondock. When we do (at a motorcross track or rodeo facilities), there will be scores of trailers running generators through the night. We don't have any plans in the near or mid term to do any "real" boondocking like many on here seem to. If our mission changes or I determine that the one is completely inadequate, I can easily add one or possibly two of these same batteries. My 4018 is pretty heavy on the front end so If I can get away with the one, I can knock just short of 600# off my front end. Has anyone else tried this? If yes, how did it go?

I recently discussed this:

Question - Do RV's come with too many house batteries?

Here's a thought, and mainly for my Class A friends. Why do motorhomes come with so many batteries? I opted for 8 lead acid in my Newmar Ventana which came out to 900 amp hours. 50% of that is usable in lead acid and AGM batteries. But is it really necessary? All of that weight? Here is why I...

rvforums.com

 

[newmarokie]

Neal, thanks. I thought I had looked at every thread pertaining to this. I missed that one. BIM= battery isolation module. My coach has one but it is not a Li-Bim. It will have to be replaced. I keep looking at youtube videos for tips. I have seen a couple that talk about battery charge controllers. Does anyone know if the BMS that is in the SOK280 handles that.

 

[Neal]

There is a solar charge controller that some may be referring to, otherwise your charger is your inverter.

 

[LMHS]

You need at least one "ah" per day. An "ah" is an interjection that is measurement of either attaining pleasure or knowledge.

An "AH" is an amp hour and should not be confused with "ah", the interjection.

 

[TheLooks]

There is a solar charge controller that some may be referring to, otherwise your charger is your inverter.

You mean the inverter/converter? I assume a large MH has the consolidated unit.

 

[Neal]

If you have solar it has its own charger that connects to the batteries.

 

[Rich W.]

You mean the inverter/converter? I assume a large MH has the consolidated unit.

Inverter/Charger. With the larger battery banks found on a DP there is no need for a converter. This is one of the minor stumbling blocks you run into if converting your battery bank to a 24v or 48v system. Somehow you still need to include a good 12v source to run the higher load 12v stuff like slides and jacks.

 

[TheLooks]

Inverter/Charger. With the larger battery banks found on a DP there is no need for a converter. This is one of the minor stumbling blocks you run into if converting your battery bank to a 24v or 48v system. Somehow you still need to include a good 12v source to run the higher load 12v stuff like slides and jacks.

Yes, you still need a converter. An inverter does not provide 12vdc to anything. It uses it to make 120v AC.....Terminology is important sometimes. You have converters, inverters, and consolidated units that do both. But they are separate functions of the same unit.

 

[Rich W.]

Yes, you still need a converter. An inverter does not provide 12vdc to anything. It uses it to make 120v AC.....Terminology is important sometimes. You have converters, inverters, and consolidated units that do both. But they are separate functions of the same unit.

Right but there is no need for a converter (120v AC to 12v DC) when you have a big enough 12v battery bank to handle the 12v loads. Conversely the use of a bigger inverter (12v DC to 120V AC) is made possible by the same higher capacity battery bank.

My Bay Star had a converter which provided 12v DC because it only had two 12v house batteries (typical for a gas class A), and even after I installed a large Li-ion battery bank I retained the converter to provide 12v DC because my battery bank was 24v (charging up to 32.8v with solar) and while it wasn’t highly efficient, the converter got its 120v from the inverter. So by using a 12v converter powered by a 3kw Victron inverter off a 24v battery bank, I was still able to make 12v DC for the slides and jacks.

With the battery banks on DPs there is no need for a converter because you have a big enough 12v battery bank to handle the loads and it is charged by the inverter/charger when on shore or gen power - the reason many say to run your slides in and out either on shore or gen power, although with a healthy, well charged battery bank this isn’t necessary. Converters are needed on trailers, campers, and most gas coaches because they lack a sufficient battery bank and a big enough inverter/charger.

 

[johndependence]

Allen,
As near as I can tell, the only additional equipment needed is a BIM. All the other changes are completed on the panel. So, if there is more, I am not aware. I asked yesterday and got very little info. The battery I am looking at has self contained heat and BMS

You will need a lithium battery isolation monitor. You will have to change settings on your inverter as well. You will.habw a Magnum or a Victron.

 

[Kevin D Pem]

How confusing to a newbie! Could someone explain to me so I can understand please?

 

[TheLooks]

Right but there is no need for a converter (120v AC to 12v DC) when you have a big enough 12v battery bank to handle the 12v loads. Conversely the use of a bigger inverter (12v DC to 120V AC) is made possible by the same higher capacity battery bank.

My Bay Star had a converter which provided 12v DC because it only had two 12v house batteries (typical for a gas class A), and even after I installed a large Li-ion battery bank I retained the converter to provide 12v DC because my battery bank was 24v (charging up to 32.8v with solar) and while it wasn’t highly efficient, the converter got its 120v from the inverter. So by using a 12v converter powered by a 3kw Victron inverter off a 24v battery bank, I was still able to make 12v DC for the slides and jacks.

With the battery banks on DPs there is no need for a converter because you have a big enough 12v battery bank to handle the loads and it is charged by the inverter/charger when on shore or gen power - the reason many say to run your slides in and out either on shore or gen power, although with a healthy, well charged battery bank this isn’t necessary. Converters are needed on trailers, campers, and most gas coaches because they lack a sufficient battery bank and a big enough inverter/charger.

You are calling your convertor a charger, that is all. Terminology.

 

[Neal]

You are calling your convertor a charger, that is all. Terminology.

I do not believe inverter, converter, and charger are the same. Some may combine functionality, for example my Victron inverter is also a charger. I can isolate it so that it's only an inverter and not a charger.

 

[TheLooks]

Your Victron is not standard equipment and the real difference is how many amps can be supplied. A convertor puts our more amps and can stand alone, a charger puts out fewer amps and gradually builds the charge. If you have an inverter/charger, you must have shore power or enough batteries to hold out for longer times.

 

[Kevin D Pem]

I do not believe inverter, converter, and charger are the same. Some may combine functionality, for example my Victron inverter is also a charger. I can isolate it so that it's only an inverter and not a charger.

Sorry @Neal an inverter is an inverter, however an inverter/charger has the function of a converter, because a converter is nothing more than a charger designed to supply a continuous current! Or put another way a converter is a robust 12vdc charger.

The only point not covered, is most of the equipment in an RV does not contain built-in solar charge controllers. When all functions are built into the offerings, things will get much more convenient, albeit much more expensive!