Reply
 
Thread Tools Display Modes
Old 02-24-2016, 12:47 PM   #11
Senior member
 
Join Date: Mar 2015
Location: toms river nj
Posts: 41
battery charging

had that problem with my 335 only had it few months. Lucky I was camping 2 miles from my tech man. Frig and battery only working shore power and inverter keep tripping. Found that cables on battery were not secure, needed to be cleaned and reconnected same. Year later and no recurrence of that issue
__________________

__________________
efgsr47 is offline   Reply With Quote
Old 02-25-2016, 01:49 AM   #12
Senior Member
 
Join Date: May 2012
Posts: 513
Quote:
Originally Posted by ScottBrownstein View Post
Not to be a stickler here, but if his frig runs off an inverter, it isn't a propane/120 VAC unit, it is a residential model. As such, it has never,ever heard of 12 volts! i suppose you could power an LP/AC reefer off of an inverter but that really would make no sense.
Our 2011 Georgetown 327DS has a Dometic propane/AC fridge that we run off of an inverter. I purchased the inverter and had the dealer install it before the rig went out on its first trip because I didn't want to drive with the propane on and couldn't see running the 5500W generator for a 300W intermittent load for the fridge. When we're driving, the 175A alternator provides more than enough power to run the inverter, charge the batteries, and still meet the chassis electrical needs. The inverter has an internal transfer switch and was wired into the electrical system so that it automatically shuts off whenever shore power is available or the generator is running.

I also installed a switch in the propane solenoid power line from the propane detector. This lets me shut off the propane at the tank from inside the rv when we're driving.

Phil
__________________

__________________
pmsherman is offline   Reply With Quote
Old 02-25-2016, 09:36 AM   #13
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 1,587
Quote:
Originally Posted by pmsherman View Post
Our 2011 Georgetown 327DS has a Dometic propane/AC fridge that we run off of an inverter. I purchased the inverter and had the dealer install it before the rig went out on its first trip because I didn't want to drive with the propane on and couldn't see running the 5500W generator for a 300W intermittent load for the fridge...
Phil
Makes sense, that's a new one for me, never heard of anyone doing that. I guess as long as the alternator is supplying the power it's no problem. When running from batteries, the AC section of a propane/AC reefer is really inefficient as it is merely a hot wire resistance heater. Taking 12 volts to make 110 to make heat is not a very optimal process.
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 02-28-2016, 10:18 PM   #14
Senior Member
 
Join Date: Mar 2014
Posts: 969
Quote:
Originally Posted by pmsherman View Post
Our 2011 Georgetown 327DS has a Dometic propane/AC fridge that we run off of an inverter. I purchased the inverter and had the dealer install it before the rig went out on its first trip because I didn't want to drive with the propane on and couldn't see running the 5500W generator for a 300W intermittent load for the fridge. When we're driving, the 175A alternator provides more than enough power to run the inverter, charge the batteries, and still meet the chassis electrical needs. The inverter has an internal transfer switch and was wired into the electrical system so that it automatically shuts off whenever shore power is available or the generator is running.

Phil
Phil

The only issue I see is whether or not the wiring from the alternator to the inverter is heavy enough to support the 25 amp plus load you are putting on the alternator. Depending on the distance, you want at least 6 gauge wires making that run to avoid the voltage drop. If you have much of a voltage drop, the batteries are going to carry the load instead of the alternator (and the batteries will not be charging).

Fred W
__________________
pgandw is offline   Reply With Quote
Old 02-29-2016, 09:07 AM   #15
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 1,587
Quote:
Originally Posted by pgandw View Post
Phil

The only issue I see is whether or not the wiring from the alternator to the inverter is heavy enough to support the 25 amp plus load you are putting on the alternator. Depending on the distance, you want at least 6 gauge wires making that run to avoid the voltage drop. If you have much of a voltage drop, the batteries are going to carry the load instead of the alternator (and the batteries will not be charging).

Fred W
On a class A chassis the alternator feed is designed to support a residential refrigerator and inverter option. That means that the feed will handle an inverter load with no problems and still manage to top off the house battery bank.
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 03-02-2016, 02:21 AM   #16
Senior Member
 
Join Date: May 2012
Posts: 513
Quote:
Originally Posted by pgandw View Post
Phil

The only issue I see is whether or not the wiring from the alternator to the inverter is heavy enough to support the 25 amp plus load you are putting on the alternator. Depending on the distance, you want at least 6 gauge wires making that run to avoid the voltage drop. If you have much of a voltage drop, the batteries are going to carry the load instead of the alternator (and the batteries will not be charging).

Fred W
Actually, it's the wiring from the alternator to the battery, not the inverter. I believe the dealer used 2/0 wire from the battery to the inverter, around 6'. The inverter draws 25-27A at 12V when the heater in the fridge is running. Next time I'm running it that way, I'll check the house battery voltage while the fridge is drawing power for its heater. I have a two decimal DVM monitoring the battery so it should be easy to see the voltage drop.

Newer units with residential fridges would have a charge wire heavy enough to carry the current needed for the inverter but since mine didn't have that type of fridge, I might have a smaller charge wire. 20' of #10 wire has a resistance of 0.02 ohm. At 25A, this would cause a 0.5V drop in the voltage delivered to the battery. #8 wire would be 0.013 ohms, with a corresponding voltage drop of 0.325V.

Phil
__________________
pmsherman is offline   Reply With Quote
Old 03-02-2016, 10:08 AM   #17
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 1,587
[QUOTE=...Newer units with residential fridges would have a charge wire heavy enough to carry the current needed for the inverter but since mine didn't have that type of fridge, I might have a smaller charge wire. 20' of #10 wire has a resistance of 0.02 ohm. At 25A, this would cause a 0.5V drop in the voltage delivered to the battery. #8 wire would be 0.013 ohms, with a corresponding voltage drop of 0.325V.

Phil[/QUOTE]

I doubt that. The wires from the alternator are designed to charge the battery bank, regardless of what is drawing it down. My bet is #6 since FR seems to use it in the battery section, with the exception of inter battery and battery to BCC wiring, which is #4. In fact, I have a 25 foot run of #6 from my 70 AMP converter to the battery bank. Sure it is rated for 70 amps, but has a big voltage drop at that length with 70 amps...but then it hardly ever puts out 70 amps...but the #6 has a lot to do with that!

Imagine what it would be like to build one if you constantly had to refer to a build sheet for wiring that every coach has!
__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Old 03-05-2016, 04:12 PM   #18
Senior Member
 
Join Date: May 2012
Posts: 513
Quote:
Originally Posted by ScottBrownstein View Post
I doubt that. The wires from the alternator are designed to charge the battery bank, regardless of what is drawing it down. My bet is #6 since FR seems to use it in the battery section, with the exception of inter battery and battery to BCC wiring, which is #4. In fact, I have a 25 foot run of #6 from my 70 AMP converter to the battery bank. Sure it is rated for 70 amps, but has a big voltage drop at that length with 70 amps...but then it hardly ever puts out 70 amps...but the #6 has a lot to do with that!

Imagine what it would be like to build one if you constantly had to refer to a build sheet for wiring that every coach has!
I measured the effects of the inverter drawing 26A for the fridge heater. The voltage drop is 0.20V which leads me to suspect that the charge wire is around 12' of #8. If I run the inverter at full output, 1kw, that would be around 100A and would have a voltage drop of 0.8V. With 14.1V at the alternator, that's still 13.3V at the battery which should keep it charged. Of course, running 100A through a #8 wire exceeds its rated capacity which will cause it to heat up, increasing its resistance. #8 wire, used for chassis wiring (not in a bundle), is "conservatively" rated at 73A. ( American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire breaking strength ).

Phil
__________________

__________________
pmsherman is offline   Reply With Quote
Reply

Tags
battery, charging

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Virginia Campgrounds

Reviews provided by




ForestRiverForums.com is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 03:58 AM.