4 6v batteries better than 2 12v?

[1carguy]

My batteries are going to be 3 years old soon and seem to be holding up well but I think they should be replaced soon. What would be the benefit in installing 4 6v batteries instead of 2 12v batteries? Would I gain longer use of the batteries when not using shore power? Do they charge up faster or slower from the inverter? If there is no real gain, I might as well go the easy way and stick with the 2 12v batteries.

[curver900]

if you don't do allot of dry camping stick with the 2 12v.. if you are going to do allot of dry camping then go with the 4 6v... their charge will last much longer...

all things considered the charge rates are about the same...

[Stingray75]

Ditto - if you’re generally on shore power then stick with a couple 12v deep cycle batteries. If you’re occasionally overnighting without hooks-ups and you have a residential fridge then 4- 6v batteries could be a smart move but there will be additional weight to consider.

[Lake Huron]

Like curver said...
I have a group size 31 Duracell AGM in my Northpoint, dont really do much dry camping but it will carry the trailer pretty easily for a weekend if we did. It just completed its 5th season and is still going strong. I have a residential fridge in my trailer and it is powered separately from the main coach battery by a pair of Interstate 6v's. The fridge pulls a lot of draw on start up and when it goes into defrost mode.
If you dont do a lot of dry camping look into a bigger battery size like I got and see if that'll fit your needs.

[RetiredOne]

OK, question for you boondocking dudes. Looking for opinion based on experience.

So far, we have only camped using shore power and conventional campgrounds. Gotta break wifey into this dry camping gently. I have two standard Group 24 deep cycle batteries in my rig. We are planning on doing an overnight without hookups, and wondering if these two batteries will last the night. My first guess is yes.

Can't run the genny overnight because of "quiet times", so we'll be on batteries only. Temps will be in upper 40's overnight, so furnace will be cycling. Fridge and hot water will be on propane. Will probably run a TV for a few hours at night, few lights, charge phones overnight on the batteries. Wifey will probably want to cycle the coffee maker in the morning off of the inverter/batteries before genny start.

So, opinions, think there will be any issues with the two batteries lasting overnight?

Another question, I know many fire up their gennys to recharge and top off the batteries in the morning, but does anyone fire up the engine on the rig instead to top them off. My house batteries charge when the engine is running too. The Ford V10 has a 120 Amp alternator, I believe. I'm thinking that in the morning, I can just fire up the engine and let it idle to top off batteries. At the same time, I can run the cab heater to heat the coach.

One thing I noticed, it seems the rigs engine is quieter than the racket from the Genny, and if it puts out enough Amps to charge the batteries, does anyone do this, as an alternative way to top off the batteries?

[Danno]

I use 2 6v batteries and one 100 watt solar panel. 95% of our camping is boondocking. never had an issue of the batteries going low. Only a small 2000watt genny for coffee and microwave. You would need to run the genny for hours to try and charge the batteries.

[EA37TS]

Originally Posted by RetiredOne

OK, question for you boondocking dudes. Looking for opinion based on experience.

So far, we have only camped using shore power and conventional campgrounds. Gotta break wifey into this dry camping gently. I have two standard Group 24 deep cycle batteries in my rig. We are planning on doing an overnight without hookups, and wondering if these two batteries will last the night. My first guess is yes.

Can't run the genny overnight because of "quiet times", so we'll be on batteries only. Temps will be in upper 40's overnight, so furnace will be cycling. Fridge and hot water will be on propane. Will probably run a TV for a few hours at night, few lights, charge phones overnight on the batteries. Wifey will probably want to cycle the coffee maker in the morning off of the inverter/batteries before genny start.

So, opinions, think there will be any issues with the two batteries lasting overnight?

Another question, I know many fire up their gennys to recharge and top off the batteries in the morning, but does anyone fire up the engine on the rig instead to top them off. My house batteries charge when the engine is running too. The Ford V10 has a 120 Amp alternator, I believe. I'm thinking that in the morning, I can just fire up the engine and let it idle to top off batteries. At the same time, I can run the cab heater to heat the coach.

One thing I noticed, it seems the rigs engine is quieter than the racket from the Genny, and if it puts out enough Amps to charge the batteries, does anyone do this, as an alternative way to top off the batteries?

My experience with most vehicles is they do not charge batteries when the engine is running at an idle. The engine must be at a high idle or higher RPM in order for the alternator to put out the power necessary to charge the batteries. The BIRD on your rig will not close allowing the house batteries to charge until the alternator voltage gets higher than a certain level. Using the generator may be your best bet.

[RetiredOne]

Originally Posted by EA37TS

The BIRD on your rig will not close allowing the house batteries to charge until the alternator voltage gets higher than a certain level. Using the generator may be your best bet.

I remember when I got my rig, I was playing around, trying to figure out what's charging what, and I remember putting a digital meter on the coach battery and saw the voltage jump up when the engine was just idling in the driveway. Now, I don't know what the total output or regulation is at idle versus higher RPMs, but something is going to the batteries from the engine during idle.

[Isaacs]

Your furnace fan and coffee maker will probably use much more power than all the other things combined.

There's not much you can do about the furnace fan except keep the temperature low once you've crawled into some decent sleeping bags.

The coffee maker can be replaced with an inexpensive percolator that sits on your propane stove.

[CAG]

We don't do that much dry camping any longer. If I do it is hunting and removed from any hookups. I have used 2-6 volts for extended dry camping/hunting and the generator runs in the AM for coffee/microwave and again in the evening for Fox News and the microwave we have gone 10-14 days with no issues. That includes nights in the teens or lower but we keep the thermostat on 55 and a Big Buddy heater to add to the forced air. The underbelly needs heat to keep things from freezing when it gets that low.

A year or so ago I switched to 3 12v-AGMs to avoid having to deal with watering batteries and the off chance of a 6 volt failure and no power at all. I found the AGMs to work very well for the dry camping and hunting trips.

Bottom line to this is you have to decide what you are looking for and how you want to supply your power needs. I never really considered solar since we seldom parked in the hot, sun of Arizona when dry camping. The generator was the recharge source.

So, are you looking to stay off-grid, or just to have enough battery to not worry about a generator? It kinda, comes down to a personal decision and your needs. If you never dry camp you don't really need to worry about how many batteries. One 12 volt is enough.

[Jagiven]

Three year old batteries aren't very old if they are being maintained. My current batteries are now 8 years old. I have to admit, I know they won't last much longer.

The key to good battery life is to check the fluid levels periodically. During the summer, I check them maybe twice. In the fall and spring once again. If fluid is required. ONLY add DISTILLED water, any other water has minerals and will short out the cells.

[JimD]

Originally Posted by RetiredOne

OK, question for you boondocking dudes. Looking for opinion based on experience.

So far, we have only camped using shore power and conventional campgrounds. Gotta break wifey into this dry camping gently. I have two standard Group 24 deep cycle batteries in my rig. We are planning on doing an overnight without hookups, and wondering if these two batteries will last the night. My first guess is yes.

Can't run the genny overnight because of "quiet times", so we'll be on batteries only. Temps will be in upper 40's overnight, so furnace will be cycling. Fridge and hot water will be on propane. Will probably run a TV for a few hours at night, few lights, charge phones overnight on the batteries. Wifey will probably want to cycle the coffee maker in the morning off of the inverter/batteries before genny start.

So, opinions, think there will be any issues with the two batteries lasting overnight?

Another question, I know many fire up their gennys to recharge and top off the batteries in the morning, but does anyone fire up the engine on the rig instead to top them off. My house batteries charge when the engine is running too. The Ford V10 has a 120 Amp alternator, I believe. I'm thinking that in the morning, I can just fire up the engine and let it idle to top off batteries. At the same time, I can run the cab heater to heat the coach.

One thing I noticed, it seems the rigs engine is quieter than the racket from the Genny, and if it puts out enough Amps to charge the batteries, does anyone do this, as an alternative way to top off the batteries?

90% boondocking with 2 group 27s & 200 watt solar. If the batteries are mostly charged I can watch a few hours of TV at night off the inverter plus run the furnace overnight (Southern California so not freezing here) without problem. Batteries will need charging for sure in the morning.

To top off my batteries I use a little 2200 watt inverter generator instead of my 4k unit. Saves wear and tear on the expensive generator plus will run all day on a gallon of gas and is a lot quieter. This was my best investment! I fire it up in the afternoon and shut it down at quiet time.

I very much doubt the alternator will be able to charge the house batteries as well as the converter. My converter is 60 amp and will work to capacity when my batteries are low. For the alternator to be able to charge the batteries with any amperage you would need to be well above an idle. Even then the gauge of the wire going from the alternator to the house batteries will probably be too small to allow as much current to flow as would be needed.

[billcf7]

Originally Posted by 1carguy

My batteries are going to be 3 years old soon and seem to be holding up well but I think they should be replaced soon. What would be the benefit in installing 4 6v batteries instead of 2 12v batteries? Would I gain longer use of the batteries when not using shore power? Do they charge up faster or slower from the inverter? If there is no real gain, I might as well go the easy way and stick with the 2 12v batteries.

If you can afford it go with 2 12 volt lithium iron batteries. You will probably never have to buy batteries again and they will give you twice the usable power between charges and can be charged faster than acid or agm

[RetiredOne]

Originally Posted by JimD

I very much doubt the alternator will be able to charge the house batteries as well as the converter. My converter is 60 amp and will work to capacity when my batteries are low. For the alternator to be able to charge the batteries with any amperage you would need to be well above an idle. Even then the gauge of the wire going from the alternator to the house batteries will probably be too small to allow as much current to flow as would be needed.

Yeah, I would assume the alternator can't put out like the converter can, but to put some juice back into the batteries as well as take the chill off the coach, it should do something, versus listening to the racket and vibration from the 4K genny.

Only way I'll know is to throw a ammeter on the alternator when it's idling to see what it's sending to the batteries.

[JFlightRisk]

Here's a little light reading on alternators, and regulators. Taken from this site.

Charging System Basics

"Current Demand and Flow:
If you have an alternator that can produce 120 amps of current (max) and the the total current demand from the electrical accessories (including the battery) is only 20 amps, the alternator will only produce the necessary current (20 amps) to maintain the target voltage (which is determined by the alternator's internal voltage regulator). Remember that the alternator monitors the electrical system's voltage. If the voltage starts to fall below the target voltage (approximately 13.8 volts depending on the alternator's design), the alternator produces more current to keep the voltage up. When the demand for current is low, the full current capacity of the alternator is not used/produced (a 120 amp alternator does not continuously produce 120 amps unless there is a sufficient current draw)."

[Danno]

Originally Posted by JimD

To top off my batteries I use a little 2200 watt inverter generator instead of my 4k unit. Saves wear and tear on the expensive generator plus will run all day on a gallon of gas and is a lot quieter. This was my best investment! I fire it up in the afternoon and shut it down at quiet time.

FWIW, the reason we boondock is for the peace and quiet as do others. Please have respect and don't run your generator all afternoon. If you need that much power then maybe a full hook up campground is what you need. I'm sure I speak for others as to how much we hate hearing those things, no matter how quiet they are.

[poohbear]

Originally Posted by billcf7

If you can afford it go with 2 12 volt lithium iron batteries. You will probably never have to buy batteries again and they will give you twice the usable power between charges and can be charged faster than acid or agm

If you go lithium make sure your converter will charge them. My 2012 will require an upgrade to go lithium.

[RetiredOne]

Originally Posted by JFlightRisk

If you have an alternator that can produce 120 amps of current (max) and the the total current demand from the electrical accessories (including the battery) is only 20 amps, the alternator will only produce the necessary current (20 amps) to maintain the target voltage (which is determined by the alternator's internal voltage regulator).


If the voltage starts to fall below the target voltage (approximately 13.8 volts depending on the alternator's design), the alternator produces more current to keep the voltage up.

Exactly right, it will only produce what's needed, even if it has the larger capacity. There also has to be some sort of maximum output too. As example, if the coach batteries are down to 12.3 volts and the inverter is on, drawing power, what amperage output will the alternator produce to get back to the 13.8 volts? I would doubt it would be anywhere close to 120 amps, the wiring and components couldn't handle it.

[CAG]

Three year old batteries aren't very old if they are being maintained.

Unless you live in Arizona. Average battery life in a motor vehicle is 18 months to 2 years. In an RV maybe a little longer.

[1carguy]

Thanks for all the input. We do very little dry camping, mostly full hook up. Once in a while I stay overnight in the storage yard. I think I'll stick with the 2 12volts. It's cheaper and less weight. I really don't know when to replace them. They seem to hold a charge okay but I don't want to wait until we are on a trip and they fail. Maybe I'll take them to my mechanic and let him test them.