Battery Advice Please

[mddickens]

A couple elementary questions for the battery knowledgeable:


My coach is a 2020 Tiffin Allegro Red 37BA



If the "salesman switch" is off, will the chassis battery still be charged if the coach is plugged into shore power. I have noticed lately that I get a "low volt" indication for a few seconds after start up. I have been turning off the salesman switch when storing the coach and have only recently come to wonder if that is preventing the chassis battery from charging.


If I try to move the slides without the generator running and not on shore power, they move only a little and then stop. I assume the house batteries are not providing enough current. If I start the generator, or have the coach on shore power, they move in and out normally.


I have a scheduled service appt in Red Bay soon and am trying to decide if it's time to get new batteries.


Thanks for input!

[kenandterry]

Originally Posted by mddickens

A couple elementary questions for the battery knowledgeable:


My coach is a 2020 Tiffin Allegro Red 37BA



If the "salesman switch" is off, will the chassis battery still be charged if the coach is plugged into shore power. I have noticed lately that I get a "low volt" indication for a few seconds after start up. I have been turning off the salesman switch when storing the coach and have only recently come to wonder if that is preventing the chassis battery from charging.


If I try to move the slides without the generator running and not on shore power, they move only a little and then stop. I assume the house batteries are not providing enough current. If I start the generator, or have the coach on shore power, they move in and out normally.


I have a scheduled service appt in Red Bay soon and am trying to decide if it's time to get new batteries.


Thanks for input!

Not all motorhomes are built the same!!!!

Easy way to see if yours is charging the house batteries while on shore power with the “salesman switch” OFF…….

1. While disconnected from shore power for at least a couple of hours, take a reading right at the batteries with a digital meter.
2. Power up your rig via shore power, and take another reading. If your converter is doing its job, you’ll get a higher reading….maybe even 13-14 volts.
3. Of no difference in readings, turn ON your “salesman switch” and take another reading.

Moving slides in or out takes a lot of 12 volt power, so strong battery power is key.

You’ll have your answer for your rig.

[Gary RVRoamer]

You asked about chassis battery charging. However, first I have to warn you that not all coaches charge the chassis battery(s) from shore power. Hopefully another Tiffin coach owner can verify that.
Typically the chassis battery get charged after the house batteries reach near-full charge. Since the house battery may not be getting any charge with the disconnect off (disconnected), it's possible the criteria for chassis charging may never be achieved.



Sorry to be so vague, but "Not all motorhomes are built the same!!!!" definitely applies. Suggest you follow kenandterry's advice to verify what yours does.

[twinboat]

Yes, the switch needs to be on. That allows the converter/charger to charge the house batteries. As they charge, the BIM will close and allow the chassis battery to also charge.

[Iceclimber]

Test your batteries. If you are not a fan of removing them, I recommend an auto electric shop. They will happily test them and if needed, efficiently part you with your money while installing new ones. Or as a cheaper alternative buy a battery tester from Amazon. I think I paid $25 for one that works quite well.

[mddickens]

Thanks to all for the responses! I'll try leaving the battery switch on first and if I don't see any improvement, I'll do the battery test.

[Iceclimber]

I suggest a tester in your electrical kit regardless. If those are lead acid batteries the age of your coach, well they may disappoint you when it's less convenient. Check the water too, again if there is water to check. If they are AGM batteries they don't like being run down either.

[DarkSideJeep]

Originally Posted by mddickens

A couple elementary questions for the battery knowledgeable:


My coach is a 2020 Tiffin Allegro Red 37BA



If the "salesman switch" is off, will the chassis battery still be charged if the coach is plugged into shore power. I have noticed lately that I get a "low volt" indication for a few seconds after start up. I have been turning off the salesman switch when storing the coach and have only recently come to wonder if that is preventing the chassis battery from charging.


If I try to move the slides without the generator running and not on shore power, they move only a little and then stop. I assume the house batteries are not providing enough current. If I start the generator, or have the coach on shore power, they move in and out normally.


I have a scheduled service appt in Red Bay soon and am trying to decide if it's time to get new batteries.


Thanks for input!

While it is true that some coaches do not charge the batteries unless the salesman switch is on two of the 3 coaches I have owned did charge both the house and chassis batteries regardless of the salesman switch status. One of the coaches I owned was a Tiffin and it did charge the batteries while plugged in. If any of the batteries shows low voltage after sitting plugged in for a while, it could be an indication of other problems. One thing to consider is that there might be a problem with the charging circuits. The device, BIM, BIRD, or whatever, that controls battery charging may not be working correctly. The even if it is working correctly if you still have OE batteries, they are now at least 5 years old. My 2020 Jeep Gladiator is now on its' third set of batteries even though it has been driven regularly. The problem could be as simple as your batteries have reached their end of life and need to be replaced. The people at Red Bay should be able to verify how the system works and that the system is working correctly and will probably tell you the batteries need replacment.

[Gary RVRoamer]

Maybe more to the point, why turn the disconnect to the Off position if the coach is plugged to external power for charging? Even a 15A outlet is typically enough to supply battery charger and whatever other 12v needs there may be. 1 amp @ 120v will provide 10 amps of 12vd power via a converter.

[twinboat]

You will also get a low voltage indicator when starting a diesel engine in cooler weather. There are high amp intake air heaters that heat the air to limit smoke on startup.

[ViperJD]

Gary is right, on most coaches, salesman switch is only for house batteries. There is normally a second on/partially off chasis battery switch near the chasis batteires. When plugged in, all my batteries charge at same time.

[Ray,IN]

Originally Posted by Gary RVRoamer

Maybe more to the point, why turn the disconnect to the Off position if the coach is plugged to external power for charging? Even a 15A outlet is typically enough to supply battery charger and whatever other 12v needs there may be. 1 amp @ 120v will provide 10 amps of 12vd power via a converter.

[mddickens]

Originally Posted by Gary RVRoamer

Maybe more to the point, why turn the disconnect to the Off position if the coach is plugged to external power for charging? Even a 15A outlet is typically enough to supply battery charger and whatever other 12v needs there may be. 1 amp @ 120v will provide 10 amps of 12vd power via a converter.

Excellent point...leaving it on from now on!

[HighDesert]

Per Gary’s earlier comment about not all coaches charging chassis batteries when plugged in to shore power: Tiffin 32SA I had does not charge chassis batteries but RED I now have does charge them.