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Topic: Second Transfer Switch Needed To Add Inverter? (Read 1472 times) previous topic - next topic

Re: Second Transfer Switch Needed To Add Inverter?

Reply #25 –
@Caflashbob - Our's in a Front Engine Gas, but we have the step well battery bay. We can fit 4 of the 6 volt AMG Lifeline batteries in there as well as the engine start battery.

Quote from: Roger & Susan in Home2 –
My battery distributor has suggested that ages within months are OK.
This is good to know. I guess I'd better get on getting those extra batteries. :)
Husband & Wife Team. 3 Kids. 8 yo boy, 4 yo girl, 19 mth girl. Mostly Finished Renovating 1986 Grand Villa 3300 GVF SBI for a multi year trip around the country with the kids.

Re: Second Transfer Switch Needed To Add Inverter?

Reply #26 –
Let me throw out a radical idea: Instead of complicated transfer switches, why not just use the UPS (Uninterruptable Power Supply), like they have for computers, approach? In other words:

1. Run the whole coach from one or many pure sine wave inverter(s), always. Inverter(s) should be capable of running your maximum load.
2. This will provide moderate power glitch, brown-out and over-voltage protection for the rig electronics. No EMS (Electrical Management System) protection system required.
3. Charge the batteries from a shore powered charger, solar and generator, simultaneously if desired. Diodes can separate the DC power sources.

Thoughts?
1997 U270 34FT Build 5140 Cummins 8.3 Allison 3060R
Solar 1920Watts, 14KWH lithium. Orion BMS.

Re: Second Transfer Switch Needed To Add Inverter?

Reply #27 –
Mixing different type and different aged batteries is not recommended but it can be done by making modifications to mitigate the differences. I successfully mixed a seven year old Gel 8D with two new AGM (Lifeline) batteries. I installed an amp-hour meter on each battery so that I could determine how hard each battery was working. I installed the Gel battery behind the driver front wheel where Foretravel had put two house batteries, and installed the AGM batteries behind the rear passenger side wheels where Foretravel had installed the three red top start batteries. I also moved the inverter, converter, solar controller, and diode isolator to under the foot of the bed. This meant that the battery cables to the AGM batteries were much shorter than the battery cables to the Gel battery, which took advantage of the lower internal resistance that a Gel battery has. There were minor differences in how hard the batteries worked and I was surprised to discover that even the two AGM batteries did not work identical. The old Gel battery provided more amps than either new AGM. Fast forward five years and a 10 hour 10 amp test on each battery revealed that the 5 year old AGM battery capacities were 20 amp hours and 40 amp hours, while the 13 year old GEL still had 65 amp hours  capacity. I replaced all three batteries at that time.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Second Transfer Switch Needed To Add Inverter?

Reply #28 –
Tim, you said:
"Charge the batteries from a shore powered charger, solar and generator, simultaneously if desired. Diodes can separate the DC power sources."

Charging from shore or generator will use the same charger and the 120 VAC sources cannot be combined, so charging using shore and generator cannot be done.

Charging from a battery charger and solar charger at the same time can be done without the use of diodes, I often do this on cloudy days, however, the number of charging amps will be less than the sum of the amps each device can provide (charger amps plus solar amps) because each device raised the battery voltage the other device will see.  It is possible that combining two charge devices will not increase the total number of charge amps. I have amp meters (not amp hour) on each charging device separate from the amp hour meters on each battery.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Second Transfer Switch Needed To Add Inverter?

Reply #29 –
Quote from: Tim –
Let me throw out a radical idea: Instead of complicated transfer switches, why not just use the UPS (Uninterruptable Power Supply), like they have for computers, approach? In other words:

1. Run the whole coach from one or many pure sine wave inverter(s), always. Inverter(s) should be capable of running your maximum load.
2. This will provide moderate power glitch, brown-out and over-voltage protection for the rig electronics. No EMS (Electrical Management System) protection system required.
3. Charge the batteries from a shore powered charger, solar and generator, simultaneously if desired. Diodes can separate the DC power sources.

Thoughts?
I agree, I run two psw inverters all the time hard wired to tv and electronics with no bypass or transfer switches, and only turn on  big inverter as nec. for microwave, toaster etc.[not very often]
The batteries remained charged normally by solar, but I will use charger section of inverter/charger when solar doesn't keep up, or alternator when driving.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Second Transfer Switch Needed To Add Inverter?

Reply #30 –
Wyatt your post is interesting and informative.  Where and what did you use for your amp hour meters?

Factory added a third 8d gel battery cross wise in the battery compartment above the two lower ones on our 97.  Should be a bolt in if you can scrounge the slide mechanism.  Visone(sp?j had a 97 u320 they have been parting out for years.

Maybe a good source?  Four 8d gels May have advantages.  Maybe not to you. 
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4