House Battery Run Time

[charlesebrownjr]

My coach has two (2) Trace 3000 watt 12 volt inverters and six (6) 8D batteries with (2) RC7 remote control panels mounted over the windshield along with other stuff. When scrolling through various informational items contained in the displays, one display will show 25.5 hours of runtime while the other display will show just 6 hours of run time. As various appliances go on or off (refrigirator, microwave, cooktop etc) the display wii indicate various runtimes for the circuits each appliance is connected to. No problem. While at Russel coach several months ago I had Rob ck. and verify how the batteries were connected and ck there condition. I (on my own) assumed that the display showing 25.5 Hrs. runtime must have 6 batteries connected to it and the other 2 must be connected to the 2nd. display. Sounded good to me, maybe wrong! While the coach was with Xtreme Paint & Graphics having Nick Hessler go over all my CC electrical stuff, I asked him about this. Nick said that both inverters use all the batteries together. I didn' think that was correct since the displays show different runtimes. I am not far from replacing the batteries since they are approaching six (6) years of age. My thought was to add two (2) additional batteries to the inverter running the refrigirator so as to get a longer runtime for dry camping. If Nick is correct, why would CC not have kept the battery banks seperated and also why dual controls? Are alot of other coaches setup this way? Any Thoughts?

[gmcbuffalo]

Charles I have read your post three times where are the other two batteries located? I read only 6 batts.

I have 8 4D's in one bank and three inverters connected to them and all three inverters have a monitor each. The monitor are also controls for the inverters.

[truk4u]

Charles,

My RG7s are set up as the primary and slave. All functions are controlled by the primary including gen auto-start and the 2nd remote (slave) is used for a battery fuel gauge and monitoring the user selected functions. You can easily change the setup or reverse the primary and slave control. I have 5 batteries wired in parallel and my inverters are are 3000's.

Let me know when your ready for batteries.

[charlesebrownjr]

Thanks for the replys. Greg, I only have 6 batteries at this time but wii add 2 more when I replace them.

Tom I will call u win I am ready. So I assume that both inverters draw from all batteries if so, why the difference in run time? My controls seem to be as u say, a master & slave. Most of the tme I can get about 28 hrs. runtime before the Gen auto starts. Also my inverter controls do not have an AGM battery selection and shore power selection only goes to 30amps. As always, everything in my CC is working fine. I will call Xantrex about the parameters in my controls and if there might be a software upgrade to add parameters to them. Thanks guys.

[LNDYCHT]

I am not sure how your inverters are set up. In order to get run time you must have shunts ( that measures amps) on the ground side of your battery wiring to measure the draw on the batteries as well as the charge that replenishes them. In order to get an accurate number the amp hours of the batteries must be input in to the monitor. If you show a different run time on each inverter it would be reasonable to assume that there are two banks of batteries, each of which are drawn from and charged separately.

[travelite]

CharleseBrownJr, I have your identical setup in my '02 Wanderlodge LXi. Both inverters are connected to all 6 batteries, and both inverter's built-in chargers charge the battery bank. Lee's correct about the shunt. In order to get accurate battery fuel gauge information you need an external shunt - Xantrex sells a kit for this. Once the external shunt is installed, and it may already be installed, you need to go to the RC7's and alter the configuration. On the RC7 that controls the inverter that's connected to the external shunt you configure: External Shunt 'This Inverter'. You then configure the other inverter to: External Shunt 'Other Inverter'. This means only the inverter connected to the external shunt will provide accurate battery fuel gauge readout.

Each inverter has its own internal shunt on the ground terminal, but in the absence of the external shunt, each inverter will report only what it consumes; i.e., only it's local view of the world.

[charlesebrownjr]

Thanks for the help. I'll do some checking to verify my set up and my battery condition and to see if I have a shunt installed.

[mike kerley]

FWIW:

Our 93 has four 8D LifeLine batteries and they all feed the two Heart inverters. One inverter feeds outlets on one side and the other feeds the opposite side of the coach. IOTA converters charge them.

Jim Keller and I changed out our batteries last weekend after purchasing new ones from Tom at Trans Specialist (770 634 7530) at a better price than we could find anywhere else. The job was very simple with the use of a motorcycle jack to lift the batteries to the bay level, and its wheels let us roll them to and from Jim's truck. Simple job doing two at a time to minimize cable confusion. Gotta say, I saved a bunch over having them changed for me and no pain yet. Toughest part was lifting the old ones back into the truck. It helped that CC did a great job of making them very easy to get to on both buses. Much easier than changing chassis batteries.

Also, Jim's CC has two inverters with one being the primary and the second on standby until needed (load). We did not test them, but my guess is his 6 LifeLines will run that bus for many hours before the generator kicks in.

[Jon Wehrenberg]

Charles,

All the above is correct. your batteries are charged by both inverters, and both inverters draw power from them when they are not charging them.

The only thing not shared are the circuits dedicated to each inverter. Rather than frustrate yourself trying to have a gauge tell you the future (like that is going to happen), get to know your coach. You, like all of us, have "key off" loads. These are loads that are on the house batteries that we rarely think about. They are such things as the memory for our radio, clocks, the TV (even when it is off), alarm system, and any other devices that we don't see or think about. Then we have the loads we know. Lights, radio or TV, refrigerator, outlets, etc.

What you need to know is how many hours you can "dry camp" or run without recharging on your batteries. The reason your gauge cannot tell you how many hours you can go before recharging is the gauge is unlikely to know how often you open the refrigerator door, or that you just put a new case of Miller Lite in the refrigerator. It doesn't know you will have the lights on or that you will run two TVs and play a DVD on them.

After a few times you get to know just how long you can go between charges based on how you live and use electric. The time between charges is highly dependent upon the battery age and condition. The gauges probably helped a salesman sell the coach when it was new because it sounds like a great idea, but as you probably now realize the accuracy of them is based on the rate of usage at the moment you look at that feature, and not the gauge's ability to understand how you are going to use the remaining battery power.

[charlesebrownjr]

You are correct. My bus under normal living, Frig, TV & Comuter use and all the things not on but drawing power will run about 27.5 Hours before the gen kicks on. My main question was one inverter shows a run time of 25.5 Hrs. while the other show 6 Hrs. all the time. As thing go on and off like frig or aux air comp or tv the time will change at various times. ( I guess it cks every so many minutes and displays a run time) I know when there is very little draw it will show you a long run time and when under a load it will show just 6 or 8 hours. J just didn't understand why so much difference in run time if they are both drawing from all 6 batteries. Thanks for the help.