Emergency start weirdness...

[Jesse Toler]

I definitely don't see how the chassis battery would charge off of shore power. I checked all my batteries today on a volt meter and they were all 12.5 which is good. Then just for kicks I load tested them and they were also good so I think my chassis battery just got too low for my emergency start switch to work. There are still a few things that are on my mind though.

-where is the solenoid?
-and does the generator run off the house batteries or the chassis battery?

[Jesse Toler]

Originally Posted by taylorbob1

Do you mean Converter?
The unit that charges the batteries?

You're probably right. I'm not familiar to be honest. I'm used to boats. My boat definitely uses an inverter to charge the batteries. These may be different but either way I think mine is good. I see a increase in voltage when I plug in so I'm sure that's a good sign.

[16ACE27]

Originally Posted by Jesse Toler

You're probably right. I'm not familiar to be honest. I'm used to boats. My boat definitely uses an inverter to charge the batteries. These may be different but either way I think mine is good. I see a increase in voltage when I plug in so I'm sure that's a good sign.

Inverters, whether on boats or RVs or anywhere else create 120 VAC from 12 or 24 VDC. They do not charge batteries unless they are an inverter/charger combination unit.

Converters take 120 VAC and create 12 VDC to power the DC loads and charge the batteries if they battery disconnect is closed. If the battery disconnect is open, the converter will only supply DC loads on the DC buss.

[Bob Nodine]

Originally Posted by Jesse Toler

You're probably right. I'm not familiar to be honest. I'm used to boats. My boat definitely uses an inverter to charge the batteries. These may be different but either way I think mine is good. I see a increase in voltage when I plug in so I'm sure that's a good sign.

Inverter/Charger units are used in larger motorhomes. You probably have one of the units pictured below with AC circuit breakers and DC fuses. It also contains the Converter that charges the house batteries from either shore or the generator.

BIRD stands for Bidirectional Isolator Relay Delay and it will allow the alternator to charge the house batteries and the converter to charge the chassis batteries if everything is working correctly. The Delay part means that which ever power source is charging it will not close the contactor that connects the two battery systems together until the host battery system is charged. This can be a short period or a long time depending on how discharged the host battery system is. If you have the BIRD then your chassis batteries should be charged from shore power or the generator. I suspect that your house batteries (they would be the host battery system when on generator or shore) were discharged to far so the BIRD never connected the chassis batteries to be charged.

While we are on the subject there is also an IRD device. That takes the Bidirectional part out of the acronym and if you have the IRD your chassis batteries are NOT charged by shore power or the generator but your alternator will charge your house batteries after the chassis battery is charged. Sometimes folks think they have a BIRD when in fact they have an IRD. We owned a Class A diesel pusher for over 13 years and it had the IRD. I had to add a device so the chassis batteries would be charged from shore power.

[nick104]

Thanks for your reply.

[RodIndy]

Jesse, i have the same MH and mine uses the BIRD and Isolation Solenoid. Both are located under the hood on the drivers side. Read Ed Faulkner’s section on the function of the bird. Then come back your questions.
Attached is my BIRD and IS.. The lead on the right is from the chassis battery. The left one is coach batteries. When on shore or generator power, you will have 13.6 ish volts on the coach terminal. The BIRD closes the contacts inside the solenoid to connect the two banks. When you are running your engine, you will have 14.5 ish volts on the chassis terminal coming from the alternator.

[nick104]

Thanks guys. Excellent info. I'll have to explain this to the RV electrician that worked on my battery problem and was sure that when on shore power, my 2016 Axis 24.1 chassis battery was not being charged. Nick in Tennessee

[Jesse Toler]

Originally Posted by Bob Nodine

Inverter/Charger units are used in larger motorhomes. You probably have one of the units pictured below with AC circuit breakers and DC fuses. It also contains the Converter that charges the house batteries from either shore or the generator.

BIRD stands for Bidirectional Isolator Relay Delay and it will allow the alternator to charge the house batteries and the converter to charge the chassis batteries if everything is working correctly. The Delay part means that which ever power source is charging it will not close the contactor that connects the two battery systems together until the host battery system is charged. This can be a short period or a long time depending on how discharged the host battery system is. If you have the BIRD then your chassis batteries should be charged from shore power or the generator. I suspect that your house batteries (they would be the host battery system when on generator or shore) were discharged to far so the BIRD never connected the chassis batteries to be charged.

While we are on the subject there is also an IRD device. That takes the Bidirectional part out of the acronym and if you have the IRD your chassis batteries are NOT charged by shore power or the generator but your alternator will charge your house batteries after the chassis battery is charged. Sometimes folks think they have a BIRD when in fact they have an IRD. We owned a Class A diesel pusher for over 13 years and it had the IRD. I had to add a device so the chassis batteries would be charged from shore power.

This is the most clear info I've seen yet. Thank you so much for this! I'm fairly sure I have IRD. I think they didn't put BIRD in until the following year with the Vegas but I'm not 100% yet. Going to look at it shortly. Thanks again!

[Jesse Toler]

Originally Posted by RodIndy

Jesse, i have the same MH and mine uses the BIRD and Isolation Solenoid. Both are located under the hood on the drivers side. Read Ed Faulkner’s section on the function of the bird. Then come back your questions.
Attached is my BIRD and IS.. The lead on the right is from the chassis battery. The left one is coach batteries. When on shore or generator power, you will have 13.6 ish volts on the coach terminal. The BIRD closes the contacts inside the solenoid to connect the two banks. When you are running your engine, you will have 14.5 ish volts on the chassis terminal coming from the alternator.

This is awesome! Thanks for this. I'm dying to get home and test it now!