autogenstart

[Pusherpilot]

Hi all,
Posted this on other forums with no responses, thoght I'd try here!!

We're going to be boondocking for the first time with our current MH, an 04 HR Imperial. We have recently converted the Norcold to a Samsung 197. I'm curious as to where the autogenstart feature should be set to insure that the batts will have enough power in them to start the genny. The batts are about 6 mos old and are working well now.
Ron

[Mike Canter]

I use 11.8 volts on my autogen start. I have never gotten down below 12.1 volts running a fridge all night BUT I have 8 batteries. If you have 6 batteries it will get there faster. I find that my generator still starts at 11.8 volts. You may need to just try it there and if yours doesn't start then you always have the Start Boost switch to get it going.

You could try setting it at 11.8v and then see where it is in the morning and adjust from there. I have never experimented with how low of a battery voltage I can go and still start the generator. A lot would depend on how cold it is.

[nodine]

Originally Posted by Pusherpilot

Hi all,
Posted this on other forums with no responses, thoght I'd try here!!

We're going to be boondocking for the first time with our current MH, an 04 HR Imperial. We have recently converted the Norcold to a Samsung 197. I'm curious as to where the autogenstart feature should be set to insure that the batts will have enough power in them to start the genny. The batts are about 6 mos old and are working well now.
Ron

Ron,

When we installed the Samsung 197 I also put in four new six volt house batteries. I was a little puzzled that sometimes the autogenstart would start the generator within a few minutes of unplugging the shore power. I was worried about the house batteries getting to low to start the generator so had the start volts set above 12 volts. I moved it to 11.8 volts thinking that would solve the problem but sometimes the generator would still start when the batteries were almost fully charged. I decided that my autogenstart module must be reading a slight voltage drop and the voltage is actually higher than what it reads. I am guessing that when the compressor on the frig starts up there is a current surge that drops the voltage for an instant on the batteries. Evidently the autogenstart module does not have a long enough delay to filter out the temporary voltage dip. I ended up setting my start voltage at 11.4 volts and all seems fine now. What I have not done yet is run a test with the Samsung on the inverter for a long enough period to cause the generator to start. It will be interesting to see what voltage I measure at the batteries when the generator starts, if there is enough juice left in them to start the generator.

Bob

[Mike Canter]

Bob, here is the problem. 11.4 volts is somewhere between 15 and 20% charge on the batteries. Running them down that low is very bad for the batteries and causes sulfation on the plates and drastically shortens their life. Now I realize that your batteries are not really at that level and you are trying to stop the autogenstart from that sudden momentary drop in voltage. This is one of the reasons that they install eight batteries in an all electric MH is that they have the capacity to absorb that downwards voltage spike when that compressor turns on. Like I said with eight 6 volt batteries I can absorb/dampen that downwards spike in voltage when that fridge compressor turns on. So for lesser amount of batteries then that might be the solution. The big problem is at what percentage of charge does the generator actually turn on when it is set at 11.4 volts? Will the fridge kick on the generator before it gets too low in voltage to start the generator or will the batteries just get too low to automatically start the generator?

[Pusherpilot]

Originally Posted by nodine

Ron,

When we installed the Samsung 197 I also put in four new six volt house batteries. I was a little puzzled that sometimes the autogenstart would start the generator within a few minutes of unplugging the shore power. I was worried about the house batteries getting to low to start the generator so had the start volts set above 12 volts. I moved it to 11.8 volts thinking that would solve the problem but sometimes the generator would still start when the batteries were almost fully charged. I decided that my autogenstart module must be reading a slight voltage drop and the voltage is actually higher than what it reads. I am guessing that when the compressor on the frig starts up there is a current surge that drops the voltage for an instant on the batteries. Evidently the autogenstart module does not have a long enough delay to filter out the temporary voltage dip. I ended up setting my start voltage at 11.4 volts and all seems fine now. What I have not done yet is run a test with the Samsung on the inverter for a long enough period to cause the generator to start. It will be interesting to see what voltage I measure at the batteries when the generator starts, if there is enough juice left in them to start the generator.

Bob

We replaced 4 6v batts as well. It'll be interesting to see if ours acts the same way as yours does.
Ron

[itdave]

Bob,
There may be another solution to the problem. I was just checking out the manual for the ME-AGS revision 3.5 and higher. This is an upgrade to the version I have in my 06 Endeavor. In the manual it says it will not start the generator until the voltage has been under the DC Start Volts setting for 2 minutes. I know that in my version as soon as the voltage drops below the Start Volts setting my generator starts. I wonder if the newer vision added the delay feature. I think I remember Magnum tell me it cost $100.00 to upgrade to the newer version which has all the settings done from the remote control instead of having to set some things from the unit by the inverter.

[nodine]

Originally Posted by itdave

Bob,
There may be another solution to the problem. I was just checking out the manual for the ME-AGS revision 3.5 and higher. This is an upgrade to the version I have in my 06 Endeavor. In the manual it says it will not start the generator until the voltage has been under the DC Start Volts setting for 2 minutes. I know that in my version as soon as the voltage drops below the Start Volts setting my generator starts. I wonder if the newer vision added the delay feature. I think I remember Magnum tell me it cost $100.00 to upgrade to the newer version which has all the settings done from the remote control instead of having to set some things from the unit by the inverter.

Dave,

I have software version 3.7. The problem seems to be that the AGS is reading 0.8 volts lower than the actual battery voltage. This version of software will tell you what the AGS voltage is and it says 12.6 but the float charge reading on the display is 13.4. That means that if I set the gen start voltage at 11.4 it will start the generator when the voltage drops to 12.2 volts. That should not be to low. As I said, I need to leave the frig on inverter until the AGS starts the generator. The only problem is I don't have a meter handy that will store readings over time. I need to come up with a data logger. Thanks for pointing out the 2 min delay.

Bob

[nodine]

To verify the voltage readings indicated by the remote display I just went out with a meter and measured 13.48 VDC across the terminals of the house batteries and 12.34 VDC between terminals 3 and 4 on the AGS. Over a volt is being dropped between the battery and the AGS. That will certainly explain why the AGS needs to be set at 11.4 volts to keep the generator from starting only a few minutes after disconnecting the shore power. I now believe that when the AGS was set to 12 volts it would start the genset when the surface charge on the batteries depleted. That could be a short period of time even with a small load on the batteries. Now do I want to go to the trouble of fixing this or just compensate by setting the start voltage 1 volt below what I want the actual start voltage to be.

Bob