Battery voltage while boondocking

[mmorgan]

Just curious as to what other people are doing, when boondocking, at what battery voltage do you start the generator and recharge?

In the past when I see 11.9 volts I would recharge.



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[Skip426]

Most battery related questions , are answered on this site, below.
The lower the voltage , the longer the re-charge time.

The 12volt Side of Life (Part 1)

[PJStough]

Also, the lower the voltage, the shorter the battery life.

[530ktm]

Originally Posted by mmorgan

Just curious as to what other people are doing, when boondocking, at what battery voltage do you start the generator and recharge?

In the past when I see 11.9 volts I would recharge.



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11.9 volts is pretty low. If you boondock why not look into some solar to keep things up. My batteries are usually at 12.3 volts or more in the mornings and are pretty much charged up by mid day and never have a need to run generator, unless microwave or A/C of course.

[okcnewbie]

A 50% SOC is a good value to shoot for if you're trying to keep generator usage to a minimum.

The problem is that under load the 50% point could be reading under 12 volts while under load. You could get to 11.9 under your "regular" load than let the batteries sit for a while and measure. After the battery recovers see if you read 12.1 or higher. If so, than 11.9 is pretty close for your setup IMO.

[WYRon]

You will get a bit of contradictory advise in some cases because the voltage you read, especially if you have auto-generator start, may not reflect the real state of charge. For example, if the 50% level for a particular battery is 12.2 volts, that is the "resting" voltage with no significant draw. If you operate a microwave, coffee pot, or other large current draw devices the voltage may drop from 12.4 to perhaps 12.0 and cause a false generator start. Therefore some people recommend an 11.9 volt setting to avoid the false generator start. Personally, I use AGS when there won't be a significant current draw, like in storage or during the day when we're away but boondocking, and set it for 12.2 volts. When in the coach, I switch off AGS and manually decide when to start the generator based on "resting" voltage. I also have a battery monitor (current shunt), so can get a pretty good idea of the actual state of charge.

[mmorgan]

Thanks for all the replies, I do not do a lot of boondocking or I would have solar.

Just curious to know what other people do, I occasionally stay the night at Walmart and a couple other places so just curious when to start gen.



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[vsheetz]

I use 12.0 volts. Close enough to the 50℅ SOC, however whenever you measure it, IMHO. And easy to remember. Has stood me in good stead for many years of boondocking with three diffent coaches.

[Kiawah]

I occasionally stay the night at Walmart and a couple other places so just curious when to start gen.

You're not having to start your generator for an overnight sleep....right?

[dan-nickie]

I use 12.0 volts for the automatic generator start. My wife has to sleep on a heating pad so yes it will start doing an overnight.

[Gary RVRoamer]

50% SOC is the rule of thumb, but judging that accurately can be difficult. The battery voltage varies with the load on it, so the number that corresponds to 50% is not fixed unless you disconnect all loads. Most tables show 12.0 or maybe 12.06, but that is at rest with zero load and after stabilizing for awhile. Even a tiny amp draw would push that reading down to maybe 11.8 or 11.9, so if you just glance at the meter without disconnecting, 11.9 is probably OK.

AGMs and industrial grade deep cycles (e.g. golf cart batteries) hold up better under deep discharge than the so-called marine/RV hybrids, so an SOC of 40% is probably not at all worrisome with that battery type.

Last, the effect of occasional deeper discharges is not real significant anyway. If you aren't doing this daily, you probably won't ever notice the effect on battery life. Your battery will die of other causes long before a rare drop to 11.6 or so has much effect.

So, try to recharge at 12.0 or so, but no need to get religious about it if circumstances make that difficult.

[Redapple]

Way too technical. I run the genny every day for about a hour mid-day. I have gone 9 days with this process with no problems. If I miss a day, Batts are fine.

[mel s]

Originally Posted by mmorgan

Just curious as to what other people are doing, when boondocking, at what battery voltage do you start the generator and recharge?
In the past when I see 11.9 volts I would recharge.

mmorgan
I have 4 12V deep cycle marine house batteries and have always used 12V as the lowest/minimum house battery voltage.

BTW my current house batteries are 2 years old...(the original set lasted from 1996 to 2005 and the 2nd set lasted from 2005 to 2014).

Mel
'96 Safari 148k miles

[macnut]

That's what I do, too, but OP my be trying to program their AGS