Gulf Stream Owners RV Forum - View Single Post

Chuck v · 07-02-2017, 02:07 PM

Scott,

Sounds like you are making good progress. I did make a nomenclature mistake in my first post as the second transfer switch associated with the inverter loads is in the Xantrex inverter and not the Onan generator...

I don't have any schematics specific to this coach and would dearly like to obtain them for my own use. I do have the information that came with my generator, and since I have replaced my shore power transfer switch with one that has a surge protection and GFI built in and I have replaced my Xantrex with a Magnum pure sine inverter my data on those would not help you directly.

It does sound like your 12 volt converter may have some issues -- or perhaps your house batteries are old/damaged from their not being kept charged prior to your getting the coach. My T40C has the Intelipower 9100 series converter which may be the one on yours as well -- the manual I have for it is pretty sparse but does have a troubleshooting table that may help. Let me know if you do not have this document and I will try to scan in the table... If you replace these house batteries make sure that you replace both at the same time -- see the last paragraph below.

I can't imagine what (if anything) the dealer was thinking when they put 4 each 12 volt batteries in the front of your coach to run the Inverter and start the generator. Your inverter requires 12 input, so if wired appropriately all four of these dealer installed batteries would be in parallel. The factory configuration was 4 each 6 volt high capacity golf cart batteries connected in series/parallel to achieve a terminal voltage of 12 volts -- but at least with a higher amp-hr capacity. Even this is a compromise in terms of charge balancing and battery life. As you may know, lead acid batteries are very difficult to charge in parallel (the fully charged cells have a low impedance and a discharged cell has a high impedance, so the current needed to charge the depleted cells actually goes through the fully charged cells instead...) There is a practical reason that electric vehicles have all cells in series. At least in a series stack the same current flows through each cell and the majority of the voltage drop is across the most discharged cell with the highest impedance so the power transfer is going where it will do the most good.

Notice that the engine batteries in our coaches are also two 12 volt batteries in parallel, and the house batteries in many coaches and certainly ours are again two 12 volt batteries in parallel. This is not ideal, and it is imperative that when you change any battery in a parallel configuration that you change both...keeping vendor brand, model, capacity and manufacture date as closely matched as possible for acceptable service.

Chuck

07-02-2017, 02:07 PM	#5
Chuck v Senior Member Join Date: Dec 2009 Posts: 1,028	Scott, Sounds like you are making good progress. I did make a nomenclature mistake in my first post as the second transfer switch associated with the inverter loads is in the Xantrex inverter and not the Onan generator... I don't have any schematics specific to this coach and would dearly like to obtain them for my own use. I do have the information that came with my generator, and since I have replaced my shore power transfer switch with one that has a surge protection and GFI built in and I have replaced my Xantrex with a Magnum pure sine inverter my data on those would not help you directly. It does sound like your 12 volt converter may have some issues -- or perhaps your house batteries are old/damaged from their not being kept charged prior to your getting the coach. My T40C has the Intelipower 9100 series converter which may be the one on yours as well -- the manual I have for it is pretty sparse but does have a troubleshooting table that may help. Let me know if you do not have this document and I will try to scan in the table... If you replace these house batteries make sure that you replace both at the same time -- see the last paragraph below. I can't imagine what (if anything) the dealer was thinking when they put 4 each 12 volt batteries in the front of your coach to run the Inverter and start the generator. Your inverter requires 12 input, so if wired appropriately all four of these dealer installed batteries would be in parallel. The factory configuration was 4 each 6 volt high capacity golf cart batteries connected in series/parallel to achieve a terminal voltage of 12 volts -- but at least with a higher amp-hr capacity. Even this is a compromise in terms of charge balancing and battery life. As you may know, lead acid batteries are very difficult to charge in parallel (the fully charged cells have a low impedance and a discharged cell has a high impedance, so the current needed to charge the depleted cells actually goes through the fully charged cells instead...) There is a practical reason that electric vehicles have all cells in series. At least in a series stack the same current flows through each cell and the majority of the voltage drop is across the most discharged cell with the highest impedance so the power transfer is going where it will do the most good. Notice that the engine batteries in our coaches are also two 12 volt batteries in parallel, and the house batteries in many coaches and certainly ours are again two 12 volt batteries in parallel. This is not ideal, and it is imperative that when you change any battery in a parallel configuration that you change both...keeping vendor brand, model, capacity and manufacture date as closely matched as possible for acceptable service. Chuck __________________ 2007 Tour Master T40C Acura MDX toad "It takes a great deal of time to recover from any improvement..."