Quick generator start (AGS)

[stang37]

I don’t use the Auto Generator Start(AGS) function very often. While in for yearly maintenance I set the AGS to auto start not knowing how long we would be there. I went to retrieve some paper work and the generator was running. With the AGS set up as recommended the generator auto started after about 30 minutes on the batteries. This seems really quick with only the refrigerator on. The battery initial voltage is 13.2 VDC. Specific Gravity readings are 1.300 in all cells. I have the model MS2812 standard remote control / ME-AGS-N network, ME-RC remote control and MS 2812 series pure sine wave inverter/charge. Maybe I’m set too conservative or is this an indication of the batteries declining?

The ME-AGS-N is setup like this.

Run time (2.0 hours), Start Temperature (80 deg.), Start volts (12.2 volts), Quite time (OFF), Mode (Other)

The ME-RC is setup like this.

Searching watts (OFF), LBCO (12.0 VDC), Absorb time (1.5 hours), Battery type (Flooded),
Charge rate (80%), VAC dropout (80 VAC), Final charge setting (Multi)

[lllkrob]

Originally Posted by stang37

I don’t use the Auto Generator Start(AGS) function very often. While in for yearly maintenance I set the AGS to auto start not knowing how long we would be there. I went to retrieve some paper work and the generator was running. With the AGS set up as recommended the generator auto started after about 30 minutes on the batteries. This seems really quick with only the refrigerator on. The battery initial voltage is 13.2 VDC. Specific Gravity readings are 1.300 in all cells. I have the model MS2812 standard remote control / ME-AGS-N network, ME-RC remote control and MS 2812 series pure sine wave inverter/charge. Maybe I’m set too conservative or is this an indication of the batteries declining?

The ME-AGS-N is setup like this.

Run time (2.0 hours), Start Temperature (80 deg.), Start volts (12.2 volts), Quite time (OFF), Mode (Other)

The ME-RC is setup like this.

Searching watts (OFF), LBCO (12.0 VDC), Absorb time (1.5 hours), Battery type (Flooded),
Charge rate (80%), VAC dropout (80 VAC), Final charge setting (Multi)

Reset your start volts to 11.9.

[vsheetz]

13.2 was likely a charging voltage - not the actual start voltage. See chart I attached.

Setting the AGS start voltage can take some experimental time. Too low a voltage and the genny won't turn over when called - to high and you will get early/nusence starting. Around 12.0 is usually a good voltage.

[twinboat]

11.9 volts is a popular setting.

Your batteries won't be down to 11.9 volts when the AGS starts, but will momentarily sag to that voltage, under the inverter draw when the fridge kicks on.

The actual battery resting voltage will be higher.

[stang37]

Thanks for the input from all. I will change the start voltage to 11.9. It just seems the batteries voltage should stay up longer with just a fridge drawing off them.

[MisterT]

the LBCO(LowBatteryCutOut) should also always be a good bit lower than the start Voltage, maybe 11.5, as this will cut off the Inverter to save the batteries if the AGS fails to start the Generator, a failsafe backup 'just in case'.

the Voltage settings of 11.9 will prompt the AGS to start the generator after 2 minutes at this level.

the TEMP setting seems high, as your coach could be at 80 degrees easily during good weather, whether or not you have incoming electricity or not, it would prompt the AGS to start the generator, running for 2 hours even with incoming power. I would turn that to a very high number, like 90, unless you have pets or folks in there.

If your batteries weren't fully charged(12.8 or so) when you arrived, dropping to 12.2 might happen fairly quickly. Seems like 13.2 is more of a number while the batteries are actually still being charged.


after you've tried the new settings, and if things don't seem to improve, you can 'equalize' the batteries, when on 50a shore power, by pressing the Charger button for several seconds, then the Equalize feature will be started, running for about 4 hours. Check your water levels before you do this.
I've tried this several times over the last 3 years, and it always seems to really extend the battery time during inverter usage.

[Scottybdivin]

The Magnum AGS manual recommends 11.0 - 11.5. This is mainly for when the inverter is pulling heavier loads. Try running a coffee maker or microwave off the inverter and watch how low the voltage will drop. I've seen mine drop to 11.7V while the actual SOC was around 70%. As soon as the coffee maker was done, it jumped back to 12.3V.

[MisterT]

right, a coffee maker, like ours, will consume a large amperage while in the 'brewing' or 'percolating' mode, dropping our Voltage level from, say, 12.5 to 11.5 or so, for several seconds, then it jumps back up to 12.5, until the 'brewer' kicks in again, back down to 11.5, etc... but near the end of the cycle, it actually keeps a constant heavy draw and the Voltage stays down near the 11.5 or so... even though it gets through it's brewer cycle 'relatively' quickly - a few minutes depending on how many cups you're making. Once done, the battery Voltage reading might be back up to a more 'normal' 12.3-12.4.... it's used some battery, but not as much as it might seem during the 'temporary' brewing period.

if you set your LBCO at 11.5, and your brewing last more than 30 seconds at that Voltage reading, you may see your Inverter cut out, loosing all inverter power, including the coffee maker...

so, when I know I want to brew coffee while strictly on the Inverter only, I will 'disable' the AGS for those minutes, knowing that the 'temporary' low Voltage reading won't last long, and isn't really dropping the batteries to that level.... it's just a current reading of the draw from the coffee maker.

[Scottybdivin]

Correct. It could also apply to a microwave, hair dryer, or any other heavy load, assuming you are running off the inverter. Turning off the AGS during those times would solve the problem and allow you to have a higher start voltage. I no longer have to worry about the voltage drop since I use the SOC and temperature parameters for my AGS.

[MisterT]

what I really should correct is that I turn DOWN the LBCO setting temporarily ... not the AGS.... though, the AGS could also kick on IF the temporary low Voltage during the brewing mode keeps it below for 2 continuous minutes... sorry : )

fun ain't it!?