Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Thor Forums > Thor Community Forums > Thor Owners Community Discussions
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 01-01-2021, 06:25 PM   #1
Senior Member
 
Oneilkeys's Avatar
 
Brand: Still Looking
Model: Travato
State: Florida
Posts: 2,475
THOR #1765
Emergency Start/Battery Booster Switch

For all my electrical savvy friends out there... I have a Class B which is set up so the house batteries are charged by both the engine alternator or shore power/generator/solar panels but the chassis battery is only charged by the engine alternator. However I do have a “Battery Boost” switch which connects the chassis battery to the house batteries. My solar panels keep the house batteries at full charge all the time, but the engine battery degrades slowly.
My question - is there anything negative with taping the Battery Boost switch in the “on” position for half a day to let the solar panels charge up the chassis battery? I obviously do not want to do it permanently and i am not sure I want to do it if I am on shore power, but I cannot see any problem with temporarily taping the switch open using just the solar panels.

Thoughts?

__________________
Oneilkeys is offline   Reply With Quote
Old 01-01-2021, 07:35 PM   #2
Senior Member
 
Brand: Thor Motor Coach
Model: Axis 24.1
State: Connecticut
Posts: 1,772
THOR #20289
I suspect that if you tape the boost switch closed, you will eventually burn out the relay coil. It probably is not designed for continuous use.

David
__________________
DavidEM is offline   Reply With Quote
Old 01-01-2021, 07:47 PM   #3
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
Could you just throw a jumper cable around that switch; for short term usage?
__________________
Bob Denman is offline   Reply With Quote
Old 01-01-2021, 09:06 PM   #4
Senior Member
 
Brand: Thor Motor Coach
Model: Axis 24.1
State: Connecticut
Posts: 1,772
THOR #20289
Another thought: Leaving the battery boost switch on 24/7 will cause a continuous draw of several amps (power to the relay) that may be more than your solar system can keep up with.

Jumpering as Bob suggests shoud work as a long term storage solution. Go to a boating parts store like West Marine (the Camping World of boating) and buy a 12-18" jumper and hook it up between the two battery systems, ie across the solenoid.

David
__________________
DavidEM is offline   Reply With Quote
Old 01-01-2021, 09:10 PM   #5
Senior Member
 
Oneilkeys's Avatar
 
Brand: Still Looking
Model: Travato
State: Florida
Posts: 2,475
THOR #1765
Quote:
Originally Posted by DavidEM View Post
I suspect that if you tape the boost switch closed, you will eventually burn out the relay coil. It probably is not designed for continuous use.

David
If I was running 30-55 Amps thru it, I would agree - that’s why I would not do it while running the generator or under shore power. But I am not sure that the amperage from the solar panels is large enough to burn out the coil. But, you are right, unless I am sure, I sprint want to burn it out.
__________________
Oneilkeys is offline   Reply With Quote
Old 01-01-2021, 09:17 PM   #6
Senior Member
 
Oneilkeys's Avatar
 
Brand: Still Looking
Model: Travato
State: Florida
Posts: 2,475
THOR #1765
Quote:
Originally Posted by Bob Denman View Post
Could you just throw a jumper cable around that switch; for short term usage?
In my Winnebago Travato, the two AGM batteries are positioned on top of the rear axel and have about 1” of clearance on top. I guess I could run a jumper from the coach battery side of the coil that closes when the alternator charges the house batteries. But I dont think it is worth screwing with that system.

I guess the easiest thing is to continue to run the engine every week or so and charge it up, or hook up a small solar panel to the engine battery.
__________________
Oneilkeys is offline   Reply With Quote
Old 01-01-2021, 09:21 PM   #7
Senior Member
 
Oneilkeys's Avatar
 
Brand: Still Looking
Model: Travato
State: Florida
Posts: 2,475
THOR #1765
Quote:
Originally Posted by DavidEM View Post
Another thought: Leaving the battery boost switch on 24/7 will cause a continuous draw of several amps (power to the relay) that may be more than your solar system can keep up with.

Jumpering as Bob suggests shoud work as a long term storage solution. Go to a boating parts store like West Marine (the Camping World of boating) and buy a 12-18" jumper and hook it up between the two battery systems, ie across the solenoid.

David
I don’t intend to leave it in 24/7. It sits in my yard, so I can just leave it on during the day - once a week. The 200 watts of solar panels keeps the two AGM batteries full all the time, so I don’t think they would have any problem topping up the engine battery - during sunny daylight in south Florida.
Thanks for the thoughts.
__________________
Oneilkeys is offline   Reply With Quote
Old 01-01-2021, 09:26 PM   #8
Senior Member
 
Brand: Thor Motor Coach
Model: 37LS outlaw
State: New Jersey
Posts: 516
THOR #5248
Sounds like you have a timed isolation circuit which allows the engine to charge the house batteries when running. That circuit operates the same relay that the emergency start switch operates. The relay is made to stay energized for long periods. So you will not burn it out as you were told.

Yes you could do what you asked but if coach batteries discharge so will your chassis battery.
__________________
Trkyte@msn.com is offline   Reply With Quote
Old 01-01-2021, 09:43 PM   #9
Senior Member
 
Oneilkeys's Avatar
 
Brand: Still Looking
Model: Travato
State: Florida
Posts: 2,475
THOR #1765
Quote:
Originally Posted by Trkyte@msn.com View Post
Sounds like you have a timed isolation circuit which allows the engine to charge the house batteries when running. That circuit operates the same relay that the emergency start switch operates. The relay is made to stay energized for long periods. So you will not burn it out as you were told.

Yes you could do what you asked but if coach batteries discharge so will your chassis battery.
Thanks for the comment. I thought that might be the case - that the “battery boost” and alternator to house batteries might be the same relay. That makes sense - why have two or make it any more complicated. I would not leave the switch taped down for more than half a day (if that long) and I could routinely check it, so I am not worried about discharging the house batteries. I guess I will give Winnebago a call and see what they say. The people there seem pretty knowledgeable.
__________________
Oneilkeys is offline   Reply With Quote
Old 01-01-2021, 10:08 PM   #10
Senior Member
 
Brand: Thor Motor Coach
Model: Axis 24.1
State: Connecticut
Posts: 1,772
THOR #20289
Quote:
Originally Posted by Oneilkeys View Post
If I was running 30-55 Amps thru it, I would agree - that’s why I would not do it while running the generator or under shore power. But I am not sure that the amperage from the solar panels is large enough to burn out the coil. But, you are right, unless I am sure, I sprint want to burn it out.
It is not the charging current that goes to the battery I am speaking of. That goes through a set of contacts and should be good indefinitely. I am speaking of the current that goes from the switch to the relay coil that pulls those contacts in. That coil may not be designed for continuous use.

Re my second post: That coil can draw 5 amps or so. Your solar panels in direct sun might put out twice that but only for a few hours each day. Before 10:00 and after 2:00 you may be getting less than nothing to the chassis battery.

David
__________________
DavidEM is offline   Reply With Quote
Old 02-04-2021, 12:12 AM   #11
Junior Member
 
Brand: Thor Motor Coach
State: South Carolina
Posts: 4
THOR #22058
trickle charger

May could hook a trickle charger to the engine battery or run a wire from house to engine battery with a toggle switch in it. A old 14 ga drop cord works great for small power and has a cover over the wires to protect. Dont forget a small 15 amp fuse holder at each positive end.
__________________
bherron1 is offline   Reply With Quote
Reply

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


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 10:34 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2