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hikndog · 11-03-2014, 02:56 PM

I had Precision Paint and Interiors add the auto-gen start mod which "looks" to see if ground power is available before starting in September. Three weeks before I was dry camping and could go 12-15 hours before the auto-gen would start. Well I finally got around to test the system and it starts after about 30 minutes. Retested it today after lowering start amps to 12.2. When I trip the external breaker causing loss of shore power the batteries read 13.0/13.1 on the two inverters with a zero amp draw on one and 11 amp on the other. Eleven minutes later batteries 12.5/12.4 same amperage. After a total of 29 minutes 12.3/12.2. Any ideas on whats wrong?

brobox · 11-03-2014, 03:30 PM

Were all of the thermostats set to "off" for your test? If not, possibly the AGS was reading the temp and calling for power.

Cruzer · 11-04-2014, 07:47 AM

I would check your batteries. The 13.1 volts is a surface charge left over after having the charger running. Once you disconnect from shore power the batteries should be left to rest for 30 minutes. Then you should have 12.6 volts if the batteries are fully charged, assuming that they were fully charged to begin with. If they were, a 30 minute load of 11 amps on one inverter shouldn't drop you to 12.3 volts. I could run all night with AquaHot and other things running and still have 12.4 in the morning.

hikndog · 11-04-2014, 09:59 AM

Yes, that's the way it was before the mod. I hope to have Precision look at it next week when I'm up there for the PDI. Bit I'm still worried as there is a drain somewhere and I don't have the expertise to fix it or even know exactly whats wrong. I only know if I leave the coach not plugged in I'll have dead batteries within the hour.

loisjop · 11-04-2014, 10:59 AM

Make sure your inverter/charger settings are correct. As far as I can tell for an Anthem the charge time for absorb charging should be set at 2.5 hrs and the charge rate should be set at 70-80%. If not your batteries won't be getting full charge. Could be precision changed them erroneously. Noel

ruffian · 11-04-2014, 07:01 PM

When you said you had a 11 amp (????) was it a 11 amp 110V AC draw on the inverter which would create a 110 amp draw on the batteries.

If in fact you had a 11 amp DC draw off the batteries I wouldn't expect much change in the battery voltage.

KIX · 11-04-2014, 07:29 PM

AS I understand it ........ when your batteries read 12v not under load they are at 50% discharged. To get good battery life they should be recharged when depleted to 50% or 12v. Your AGS only reads the voltage at any given time and reacts to what it reads. The AGS doesn't know whether the system is under load or is static. So, if you set the AGS to start at 12.2 volts that can be reached fairly quickly under load. When you read 12.2 volts I suggest that you then turn off all loads, let the batteries sit for 20-30 minutes the re-read voltage. If it is at 12.2 under load then with no load the voltage will be higher. The trick is to determine while under "normal" load when the 12.0v level under no load is reached. For instance.....under load your battery bank may read 11.8v.......with that load removed it may then read 12.0v. That under load voltage is where you would set your AGS to start the gen and begin the battery re-charge.
I don't have an AGS on this coach but that's the way we set up the one on my boat.
Hope this helps you.