house / coach batteries getting used even on shore?

[Sammie]

Quote:

Originally Posted by wackodacko Hi Scott, yes I saw your post and even printed out the battery pictures so my husband could figure it out. we went to 3 different costcos in the area - none had golf cart batteries. then we saw a golf cart store, but he was charging $170/each for trojans. so we decided it would be easier to just buy 12v replacements, since autozone claims their batts have 220 amp hours a piece. However, i just called autozone to see if I could return it, they said no - they can do replacements , but not return for refund. Ive read other threads where people complain of the Dimensione 2000 OVERCharging the batteries and frying them, but in my case, the batteries are still fine - no dead cells, its just not being charged to hold a charge (or enough). ORRRRR... something in our system is leeching off the battery power big time , enough to drain all 3 batteries to below 11.8V just overnight. HRMMPPH!!

It's been my experience that when boondocking and leaving your inverter on, you Must manually switch your refrigerator over to run on propane. If you don't the refrigerator will continue to run on 110 AC and you batteries will drain in a short time. You really should shut off the inverter at night when going to bed as there is no reason to leave it on.

Sammie

[mr300ce]

After reading threads here and on several other forums evryday for over a year, (preperation for fulltiming), I have determined that RVs with a factory installed inverter come with a ATS (auto transfer switch). This turns off the inverter when shore power is plugged in.

If there is no MAJOR 12v draw sucking down the batteries, then likely the charging portion of the system has failed, either fully or partially.

[jimbo16720]

They say the furnace fan draws alot of juice and will kill batteries overnite. Never run mine so I don't know for sure.

[wackodacko]

the new batteries seem to be holding up much better than the old ones... but it will only last 9 hours if it is 5 degrees outside, and i set furnaces to: 68 degrees inside (bedroom) and 55 inside (the livingroom)
i guess this is normal..

[Dave78Chief]

From what I see in the wiring diagrams for your 2004 Horizon 40AD (Table of Contents) I do not see a converter. I do see the 2000 watt Dimensions inverter/charger (Operators manual: http://dimensions.sensata.com/Manuals/121986.pdf Technical support information: Technical Support Documents - RV).
As stated in the Inverter/Charger documentation
Bulk Stage: Max current untill 14.6 VDC is reached
Acceptance stage: Hold at 14.6VDC ramping current down until either the time value or minimum current is achieved
Float stage: 13.2 VDC, minimum current.

Just wanted to list this as you said 14.6 was Bulk stage when that is Acceptance stage.

Because the Inverter/Charger is connected directly to the coach batteries (http://www.winnebagoind.com/diagram/...ire_145020.pdf; pdf page 2) via a 300 amp fuse, the AUX Battery switch must be ON in order for the coach to see the Charger voltage.

If the Input breaker on the Inverter itself was the one that tripped, then you hit the 30 amp Automatic Power Sharing limit described on pdf page 2 of http://dimensions.sensata.com/Applic...otes/AN208.pdf. Thats a bad design for your rig because with so much of your rig driven through the inverter that means your limited to 30 amp service for a lot of your coach. Please understand, because of the design of your electrical system, that as you increase the number of space heaters on your circuits (they are routed throough the inverter) you take away from the amount of DC charging power (amperage) available for battery charging (Automatic Power Sharing limit). With 65,000 btu of furnace capability I am suprised you need the space heaters.

Documentation indicates you have a front and a rear Furnace. If both furnaces are running thats around 15 amps of current (front 40,000btu @ 9 amps; rear 25,000btu @ 6 amps). Over 8 hours thats around 72 AH of usage (15 Amps x 8hrs x .6 [cycle time]). Cycle time varies with outside temp and coach insulation efficiency. If your furnaces are running longer then increase cycle time (% of time on during each hour) to 0.8 or so. Your Group 29 batteries have around 345 AH (3 x 115AH) with only 175AH max usage (50% level). You indicated your batteries are being drawn way down (11.8VDC) down overnnight when boondocking. Thats bad bad Juju. Thats the surest way to shorten battery life to less than a year. Given that even with both furnaces running they only pull about 72AH of the 345AH available either your batteries are not getting charged up completely or you have some very large additional draws on the system. Your coach is setup so that many of the circuits are routed via the inverter and inverter panel (http://www.winnebagoind.com/diagram/...ire_145021.pdf). TV's, Sound systems, DVD players, microwaves, clocks, etc. all draw parasitic power when not in use. Turn the inverter off when boondocking overnight to reduce power consumption. Run fridge on LP when boondocking. Turn automatic steps OFF at breaker as they are a continious draw on the CHASSIS battery.

The inverter/charger supplies the 12VDC coach loads when on shore power IF the Aux battery switch is ON. Actually, the way yours is wired, the AUX battery switch has to be ON for both battery or Inverter/charger use. The Inverter/Charger does 2 things when on shore power. It supplies the coach loads and rechrges the coach battery bank. The battery bank is not supplying the load when connected to shore power. Drawings indicate you have a solar charger also. Do not get fooled into thinking the Inverter/Charger is working during dayligh hours when it is the solar providding the charge. You need to either turn off the solar or cover up the rooftop panel then read the voltage values to see if the Inverter/Charger is working. The volt meter just sees a voltage. Whether that comes from a battery, solar charger, or Inverter/charger it does not care.

Sorry for the long post but there are many possibilites and you have to know what you have and make sure your just looking at what you want to look in order to analize all this. Also, add your coach information to your signature. I had to dig up your data from your previous posts. Lots of coaches out there and the exact coach information is needed to answer many questions.

Dave

[wackodacko]

Thanks Dave for the very informative post. I've started to turn off the inverter when I sleep, it works well. however, there is usually only about 50 amps of draw which is my laptop charger, so i dont think that helps much. My Norcold Fridge is on AUTO, which im presuming means when there is no shore power, it goes to LP. are you sure i have to manually switch it to LP? If not..then it uses 12v power? that is a pain, because i'll forget to switch it back on when we're running the engine or docked somewhere...

thanks to your explanation, I now I know why, even when im on shore power - the inverter circuit breaker trips when i run the microwave and several space heaters at the same time!

[mr300ce]

My fridge goes to AC when shore power or generator are in use. Goes to propane if I manually overide, or shore power is off or genset NOT running.

NO laptop charger/power supply draws 50amps. MY 40" Sony LCD TV only draws 20amps.

I live in mine, and have shore power hooked up 24/7. I keep an eye on my battery water levels, and have to add a little every 2 mo. Next time I am going to add mineral oil to them to slow down the water loss.

I have dry camped alot, with the heater. Yes the fan draws the batteries down, but not enough to harm them if you charge them back up every other day.

[Journey39n]

Just to add my two cents.
Yes, when plugged into shore power, you will still use 12v power as well (all the 12v items). But if you are on shore power, your charger should cycle on to recharge batteries! If your batteries are running down overnight, while plugged into shore power there is something wrong with your charger circuit.
If you are on battery power only, keep in mind that inverters are not very efficient. You may only need 100 amps of power, but the inverter may use 125 amps to create it. And normally, an electric space heater hooked to an inverter, will draw batteries down very quickly.
You need to check your wiring design to find out what outlets are actually powered by the inverter. Usually it is only the TV's and an outlet or two. Most refers that run on propane are not wired to be on the inverter circuit, if the 120v cuts off, it just auto switches to propane.
Remember the difference between watts, amps, 120v, and 12v. A toaster or space heater might use 1500w, where as a LCD TV might only draw 50w, all on a 15amp fuse. To create 1000w with 120v you need 8.33 amps, but at 12v (assuming 100% inverter efficiency, which it isn't) you will need 83.33 amps. Now remember that battery you just got, with its 220 amp-hour rating, those 1000w put quite a draw on it on a cold winter night.
I had one of my 12v batteries go bad after a year, so I replaced both with CostCo 6v Golf Cart batteries. So far, so good, casino camping in cold weather, propane furnace running, watch a little tv, etc., had no hesitation when starting the generator the next morning.