LXi Parasitic Load

[davidbrady]

The bigger newer birds have a reputation for being power hogs. I've long wanted to measure the parasitic load on my house battery bank to see if this myth can be busted. I unplugged from shore power, turned off my inverters, and threw my A/T switch. I then switched off my house bank, disconnected the grounds, inserted my ammeter, and turned on my battery disconnect.

End result... drum roll please...

I have a 5 amp draw on the house bank. It would take 5.25 days to drain my battery bank down to 50% DOD.

[gondolaguy]

David,

My two gauges in the coach that register charge to my battery bank have some odd characteristics.
1) the lower gauge gets to 100% on gen charge very quickly, while the top gauge takes forever to charge up. Is this indicating two separate battery banks with one much larger?
2) I've noticed the top bank will stay on something like 52% for a really long time with gen on, then I shut off gen and come back later to see it up in the 60s.

Any thoughts on how this system works?

[davidbrady]

Hi Corey,

I'd start with your inverter configuration. It should look something like this:

1. Search Sense: 5W Load
2. Auto LBCO: ON
3. Battery Capacity: Auto
4. Battery Type: AGM
5. Charge Rate: 100% of max
6. VAC Dropout: 105 V
7. Shore Power Amps: 30 Amp
8. RC7 Setup: Last Key
9. LCD Contrast: 37%
10a. External Shunt: This inverter (for top inverter)
10b. External Shunt: Other inverter (for bottom inverter)
11. Fuel Gauge CutOut: 11.4VDC, 0% SOC

My guess is that you don't have an external shunt wired in. Look at where the inverters are housed. There should be a shunt mounted to the basement wall close to or within the inverter cabiniet (it looks like the shunts that BB uses in the engine compartment). There should be an RJ11 cable from the shunt to one of your inverters.

[pgchin]

Corey,
After you check the things David Listed, look at the battery bank cabling system. The 95-97's are NOT balanced loads, meaning 1 bank is 2 batteries, the other is 4, so indeed my non intelligent panels behave as you describe in item 1 for that reason and the FYI below. Not sure if the factory fixed the loads in the LXI's or just wired them like the 95-97's. I've had new wiring for YEARS! to balance the loads, 3 batteries each, just hasn't moved up on the short list yet!
item 2-SWAG......... you may have a bad battery in the large bank bringing down the entire bank...................you will need to disconnect and test each one with a load tester separate.....to be sure........
FYI, if you have non intelligent panels, then the two chargers "compete" for loads (all 6 batteries) with one being the master, one the slave, so one will ALWAYS shut down more quickly then the other and leave the "master" to charge ALL battery banks.......this was told to me by the Zantrex support engineers.........so you may be fine on item 1 if you have non intelligent panels......

[davidbrady]

Good points Pete. It's possible that the earlier LXi's are wired as you describe. I foolishly assumed that all LXi's are wired like mine.

On my 2002 the house bank is composed of six Lifeline 4D batteries. I have two Xantrex RV3012GS inverters each equipped with 140 Amp chargers (two inverters with integrated chargers, 280A total).

The six Lifelines are wired in parallel along with each inverter, so each inverter charges all six Lifelines and each inverter draws power from all six to support the loads on their transfer switches. My LXi uses the Xantrex integrated transfer switches which eliminates the 120VAC transfer relays scattered about.

I always thought all LXi's were wired like mine, but that's certainly a big leap in logic.

If Corey's is like mine, there's another thing to check out. The RC7 displays should be powered up before the inverters. This allows the RC7's to control the inverters. To do this I need to:

1) disconnect shore power and genny auto start,
2) turn off the inverters at each inverter rocker switch,
3) cycle the house battery disconnect switch which interrupts power to the RC7 panels (thereby resetting them),
4) wait for the RC7 panel to display "waiting for inverter",
5) then turn on the inverters.

It could be that an RC7 isn't seeing an inverter and is displaying garbage.

[gondolaguy]

(07-29-2013 18:06)davidmbrady Wrote:  Hi Corey,

I'd start with your inverter configuration. It should look something like this:

1. Search Sense: 5W Load
2. Auto LBCO: ON
3. Battery Capacity: Auto
4. Battery Type: AGM
5. Charge Rate: 100% of max
6. VAC Dropout: 105 V
7. Shore Power Amps: 30 Amp
8. RC7 Setup: Last Key
9. LCD Contrast: 37%
10a. External Shunt: This inverter (for top inverter)
10b. External Shunt: Other inverter (for bottom inverter)
11. Fuel Gauge CutOut: 11.4VDC, 0% SOC

My guess is that you don't have an external shunt wired in. Look at where the inverters are housed. There should be a shunt mounted to the basement wall close to or within the inverter cabiniet (it looks like the shunts that BB uses in the engine compartment). There should be an RJ11 cable from the shunt to one of your inverters.

I'm now back in town and looking at the config of the RC7 panels. A few settings were off, including the external shunt was set to on for bath panels. I tried to set it up like yours David. One quandary is the bottom RC7 panel does not let me choose AGM battery, it only has lead acid and gell as choices????

[davidbrady]

That's right Corey, the older Xantrex RV3000 series don't have a specific AGM battery charging schedule so you'll have to set your chargers to Flooded Lead Acid. There are some slight differences in charging voltage set points but your AGM's will hardly notice:


Xantrex RV3012 Series
Battery; Bulk/Absorption: Max V, Max I; Float: Max V
FLA; 14.4V, 30%C; 13.5V
AGM; 14.3V, 30%C; 13.45V


Lifeline AGM GPL-4DL
Bulk Charge Voltages: 14.20 - 14.60
Absorbtion Charge Voltages: 14.20 - 14.60volts
Float Charge Voltages: 13.10 - 13.40
The GPL-4DL is designed for charging amperages up to 525 amps or 250% of the rated Amp Hour Capacity due to low battery internal resistance.

[gondolaguy]

(08-02-2013 13:19)davidmbrady Wrote:  That's right Corey, the older Xantrex RV3000 series don't have a specific AGM battery charging schedule so you'll have to set your chargers to Flooded Lead Acid. There are some slight differences in charging voltage set points but your AGM's will hardly notice:


Xantrex RV3012 Series
Battery; Bulk/Absorption: Max V, Max I; Float: Max V
FLA; 14.4V, 30%C; 13.5V
AGM; 14.3V, 30%C; 13.45V


Lifeline AGM GPL-4DL
Bulk Charge Voltages: 14.20 - 14.60
Absorbtion Charge Voltages: 14.20 - 14.60volts
Float Charge Voltages: 13.10 - 13.40
The GPL-4DL is designed for charging amperages up to 525 amps or 250% of the rated Amp Hour Capacity due to low battery internal resistance.

So, the top remote did allow for AGM and I set that one there, the bottom one now acts totally different (now that I set it as the slave). The top remote seems to control all functions and is the only one reading amperage.
Thanks, I think it's working as it should now.

[davidbrady]

Corey,

Did you verify that the top RC7 is connected to the inverter that is connected to the shunt?

Did you verify that your house battery bank is wired as a single bank and that both inverters charge the entire bank? I think it should be wired this way since mine is. If this is the case I'd rather have both inverters implement the same charging algorithm which in your case would need to be FLA. Having different voltage setpoints on each charger but charging the same battery bank doesn't sit well with me. :-)

[gondolaguy]

(08-02-2013 13:52)davidmbrady Wrote:  Corey,

Did you verify that the top RC7 is connected to the inverter that is connected to the shunt?

Did you verify that your house battery bank is wired as a single bank and that both inverters charge the entire bank? I think it should be wired this way since mine is. If this is the case I'd rather have both inverters implement the same charging algorithm which in your case would need to be FLA. Having different voltage setpoints on each charger but charging the same battery bank doesn't sit well with me. :-)

Talked with both Xantrex and Lifeline. Appears it was 1999 when some of the inverters started getting the choice of AGM. Mine must bridge the gap, as one does not appear to have this choice. Lifeline says use the FLA setting for both as you guessed was correct.