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using Auto Gen start

Yahoo Message Number: 95625
I have been reading up on the forum about using Auto Gen start. It seems like the prevailing wisdom on the forum is to set it to kick in around 12.2v. I wonder if that is being overly conservative. Others state 50% but I am have no idea how you calculate the percentage. My Magnum 2800 Inverter shows voltage level charge on my house batteries. I realize the idea is not to bring the voltage down too far on your batteries as this shortens the life. And with the recent discussion on Lifeline batteries, I gather Lifelines and other AGMs can be drawn down further than wet cell without damage. I have 6 new Interstate u2200 wet cell batteries. Depending on where you read these are 200-225AH batteries.
Reading up on magnum energy's website it says the default setting for voltage for AGS is just 11.v
http://www.magnumenergy.com/Literature/Manuals/AGS/64-0039%20Rev%20A%20ME-AGS-N.pdf AGS Start Volts menu p38/103

States: Default setting at 11.0v - also says approx 50% of battery capacity which they say is 11-11.5v on typical battery voltage SOC charts
Why this huge disparity? Why would Magnum have the default setting at 11.0v but forum members are mostly recommending 12.1 or 12.2v
I also read on the forum that with the Silverleaf VMS 240 you can set your Silverleaf to start on an exercise schedule, a battery charge mode and/or a temperature mode. Our new coach has the Silverleaf VMS 240 so I guess I will have to study up on this. But can anyone tell me why I would set AGS thru Silverleaf when you can do it easily just by pushing the AGS button on the Magnum Inverter control panel?

Any clarification on all this would be much appreciated.

Joseph Burkle

2010 Tiffin Allegro Bus 43QRP

43' quad slide tag axle ISL 425 HP pusher formerly:

2008 Country Coach Inspire 360 Founders Edition http://www. Wind-seeker.com/

Re: using Auto Gen start

Reply #1 –
Yahoo Message Number: 95628
Joseph,

I have attached a link to a page showing the generally accepted State Of Charge voltage and specific gravity for lead acid batteries.

http://www.mmbalmainauto.com.au/PDF/State_of_charge_12_volt_batteries.pdf
This chart shows that batteries are fully discharged at 11.9 VDC and 50% discharged at 12.2VDC. I think that using 11.0 VDC as an AGS start point is fraught with failure.

I would use my AGS rather than the Silverleaf. It is easier to set and use and, more importantly, it has built in processes to allow for temporary voltage sag that the Silverleaf does not have,

George in Birmingham
'03 Magna 6298
George in Birmingham
2003 Magna 6298

Re: using Auto Gen start

Reply #2 –
Yahoo Message Number: 95630
While I recognize there are many different thoughts on using auto-gen start, I have to say it is the greatest system I have on my 2001 Intrigue. For what it is worth here is my experience. I bought my coach used in Nov 2002 with original Life Line batteries, with auto-genstart. I changed the batteries out in January 2012, 11.5 years of service for which I was extremely pleased. We dry camp a lot while we are in Key West for the winter, and when on the road, stop quite often at Walmart. I have the genstart set for start at 11.5 volts and stop at Float, which usually puts us at 12.9 Volts, and programmed for Quite hours. If I turn off my inverter when we go to bed, it will usually show 12.6-12.7 in the morning. While dry camping in Key West, I would estimate we use the generator 3 hours a day. Very pleased with both Life Line Batteries and Auto GenStart.

Denny Bird

2001 Intrigue 36 ft
CC# 11271

Re: using Auto Gen start

Reply #3 –
Yahoo Message Number: 95631
Hi Denny,

I agree about the auto start, but I am really wondering where you boondock in Key West. If it is not a secret, please let me know.
Larry Jenkins
McKinney, TX

Re: using Auto Gen start

Reply #4 –
Yahoo Message Number: 95632
As a real Conch, with vast living experiences as a Navy Brat in Key West (3 months old, when Dad was transferred to San Diego:)!) - I'd like to

X's 2 - Where do you Boondock in Key West:)!

(And as all CC owners know, secrets are not allowed!)

Oh, and I use the Magnum 2800 Auto Gen Start, with adjusted levels for Lifelines. Though I had to turn off the Solar Panel Midnight Classic 150 Controller, to allow the battery levels to get low enough to see the Auto Gen Start work during a test:)! I did add the BMK Meter to my package, and find it to be a great source of information.

Best to all,
Smitty

04 Allure 31017
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: using Auto Gen start

Reply #5 –
Yahoo Message Number: 95638
George, I agree with you that 11v for autgenstart is way too low no matter what kind of batteries you have. On the chart data however, Trojan wets are only down to 40% at 11.96v according to Trojan manual.

Rich 2002 Magna

Re: using Auto Gen start

Reply #6 –
Yahoo Message Number: 95640
Joseph, I have wondered about this too. I think the 11.5 default sounds way too low. Most of what I read says that 50% charge is 12V and you don't want to go any lower than 50% for battery longevity.

I am guessing that the difference in approach is the method (and timing) of measuring voltage. In order for the voltage readings to be accurate, the battery must be resting for an hour or so. A battery that us being used will always show a lower voltage than it will after it has rested. If you disconnected your battery while it was in use and indicating 11.5V, after an hour it may have recovered to 12V. Since an RV battery is almost always under some load, perhaps this is why they recommend 11.5V for AGS. Nevertheless, I choose to be conservative and set mine higher than that. Batteries are expensive!

Re: using Auto Gen start

Reply #7 –
Yahoo Message Number: 95642
Georrge - thanks so much for the link to the "state of charge" pdf. I have saved it to my manuals folder and will follow it religiously. I had had mine set on the Country Coach to 12.2 per some other advice. That's why I was kinda surprised tol find that info about 11v from Magnum. The chart you linked to makes it clear that 12.2v corresponds to 50% for perecentage of charge... that was exactly the ratios I was looking for because even Magnum says don't let the batteries drop below 50%. So 12.2v shall be my setting and I will continue to use the Magnum Inverter control for AGS to set this. I did find it interesting that you can set Siilverleaf to auto start the generator for temperature as well, thus if you leave the A/C turned on, but on 12v, it will not run until the generator kicks in and then it will cool down the coach.. a nice lifesaver for the dogs :-) Joseph Burkle

2010 Tiffin Allegro Bus 43QRP

43' quad slide tag axle ISL 425 HP pusher formerly:

2008 Country Coach Inspire 360 Founders Edition Windseeker Motor Coach - Tiffin Allegro Bus
image
Windseeker Motor Coach - Tiffin Allegro Bus [font="Helvetica Neue"]Windseeker is a 43' tag axle Class A AllegroBus luxury motorhome for RV travel across America towing our Catalina 22 in search of premiere sailing lakes[/size]
View on www. Wind-seeker.com

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Re: using Auto Gen start

Reply #8 –
Yahoo Message Number: 95654
Rich,

I would take Trojans word for it. They know their battery better than the guy that makes a generic chart about battery chemistry. You have a lot of experience and know how to do this stuff anyway.

George in Birmingham
'03 Magna 6298
George in Birmingham
2003 Magna 6298

Re: using Auto Gen start

Reply #9 –
Yahoo Message Number: 95655
Joseph,

Glad I could help.

I have a comment on using the Silverleaf to start on temperature. It should only be used when absolutely necessary. Here is why.

Leaving the thermostat on when only twelve volt is present means that as the coach warms up above thermostat set point, the A/C is being called to duty. When the generator starts and power comes on line, the A/C will start immediately rather than with the built in delay. That puts a lot of load on the cold generator and on the transfer switch. Not a big problem probably if needed for the pets but it will take a toll on the equipment. Just a thought.

George in Birmingham
'03 Magna 6298
George in Birmingham
2003 Magna 6298

Re: using Auto Gen start

Reply #10 –
Yahoo Message Number: 95658
Beaverguy14 is absolutely correct! In fact with marine batteries it was recommended to disconnect and let them set for as much as 24 hours to get an accurate voltage on a rested battery.

John

08 Intrigue
10 Ford Escape

Re: using Auto Gen start

Reply #11 –
Yahoo Message Number: 95664
This was a great comment and got me to thinking. I am sure your are right... you don't really want the A/C starting immediately as the generator kicks on... so why not set the Generator to come at say 75... and the A/C's to start when the temp reaches 80, as an example... maybe only a 3 degree spread would be necessary - I'm not sure... just some way to give the generator time to warm up and run a bit before the A/C starts. Make sense? Comments? Joseph Burkle

2010 Tiffin Allegro Bus 43QRP

43' quad slide tag axle ISL 425 HP pusher formerly:

2008 Country Coach Inspire 360 Founders Edition Windseeker Motor Coach - Tiffin Allegro Bus
image
Windseeker Motor Coach - Tiffin Allegro Bus [font="Helvetica Neue"]Windseeker is a 43' tag axle Class A AllegroBus luxury motorhome for RV travel across America towing our Catalina 22 in search of premiere sailing lakes[/size]
View on www. Wind-seeker.com

[/font]

Re: using Auto Gen start

Reply #12 –
Yahoo Message Number: 95667
Someone needs to confirm this. I believe the start delay is based on AC voltage being present, not 12 vdc.

Mikee

Re: using Auto Gen start

Reply #13 –
Yahoo Message Number: 95670
My AC units (whether in AC or heat pump mode) have a few minute delay, even if they're asking for heat/cooling immediately, so this allows plenty of time for the generator to get settled down. Same delay on shore power, so has nothing to do with generator circuit, they just don't fire up immediately on 120/240v applied.
My understanding is that this delay is built in to the AC units themselves for protection, even though the thermostat may make an immediate call for cooling. This is so that the compressors are not fired up immediately if they've but turned off without proper cooldown (ie. If power source has been abruptly removed, then perhaps reapplied, such as by thermostat powered off and on, or a shoreline breaker flipped off then on).
Mine happens to be a 2003 Lexa with auto gen start (based on battery voltage and time of day with topoff settings), but the ac behavior as described does the same delay with any 120/240 source, it just happens to allow time for generator to get settled down, whether started manually or on auto gen start.

Jim

Re: using Auto Gen start

Reply #14 –
Yahoo Message Number: 95672
Seems like it should work if you can set it that way. Good idea.

George in Birmingham
'03 Magna 6298
George in Birmingham
2003 Magna 6298

Re: using Auto Gen start

Reply #15 –
Yahoo Message Number: 95673
If you want the AC to come on sooner set the fans in the continuous mode. Then after the compressor engages you can return the fan to automatic.
TWI 2004 Intrigue 11731