My chasis battery and coach batteries were dead yesterday,I have not started the motor home in about 3 weeks, so I charged the chasis battery yesterday,preparing for a 3 hour trip, I plugged in to 50 amp shore power at my home all night and turned the fridge on. This morning, fridge fine, very cold but engine wont start and interior lights dim when turned on. New batterie 2014.Does anyone have suggestions?

In most cases the generator does charge the chassis batteries or house batteries. But normally the generator starts from these batteries also.Brian

What kind of coach? Most electrical setups charge all batteries when plugged in. Sounds like you might have a bad converter/charger. What's the voltage at the batteries? Does it change when you plug into shore power? Did you check all the breakers?

Running the generator should be the same as connecting to shore power... Make sure you do not have any BATTERY DICONNECT SWITCHes engaged. Always handy to have a DC MULTIMETER around the RVs and in this case you should read the DC VOLTAGEs at the battery terminals. A fully charged battery should read 12.6 - 12,7VDC without the generator or shore power connected.Switching to GENERATOR or SHORE POWER your battery terminals should jump to 13.6VDC or higher depending what charging mode your on-board converter/charger is doing.We take our batteries very seriously and if they ever display DC VOLTAGEs at 12.0VDC or lower we know we are experiencing battery charging problems. Batteries that get discharged below 12.0VDC (appx 50% charge state) and not get re-charged back up to at least their 90% charge state will not perform well and in most cases will be required to be replaced. We can't afford buying batteries all the time... IN your case if you are not seeing 13.6VDC or higher at your battery terminals when on Sore Power or Generator then you need to start looking for the Battery Disconnect Switch setting, in-line fuses or 12VDC circuit breaker between the converter/charger and the battery terminal, poor battery connection connection, or in the worse case a bad battery. Check the REVERSE POLARITY fuses in the Power Distribution Panel. Sometimes the batteries will boil out their fluids from being over charged and this also leads to battery failure.I lost my first new battery in about three months of use before really starting a battery maintenance plan. The remaining three batteries I currently I have on my RV setup have been performing great now since 2009. Lessons learned for me...Roy Ken

I have an 06 Winnebago and my chassis battery does not charge unless the Motor is running. I always keep my house batteries up so if the chassis battery goes dead I just hit the boost and starts the engine.

floor guy, It would be nice to know make/model/year/engine etc. of your coach so that we can give possibly more accurate answers. Gas and diesel coaches in many cases, have different electrical setups, especially for coach and chassis battery charging. And no, in many setups, the chassis battery(ies) DO NOT charge while on shore power or on gen power. Basically shore power and gen power is the same as far as the coaches 110VAC is concerned. But, take Winnebago and Itasca for example. In the pre-'06 years, especially in the diesel rigs, neither brand provided for chassis battery charging while on shore power. Many owners would come back to their rigs after extended storage periods only to find the chassis batteries dead. And, some had them stored while plugged into shore power. So, many took it upon themselves to install, what Winne and Itasca started installing from the factory in '06. And that was/is, the "Trik-L-Start" unit. It's a simple, self regulated device, NOT A BATTERY CHARGER, type thing. It's installed between the charging side of the coach batteries and, the chassis batteries. When it sees there's a 1/2 volt difference between the two sets of batteries, it kicks in and, allows SOME of the charging that's intended for the house batteries, to migrate over to the chassis batteries.It's maximum allowance is 5 amps. But, in gas coaches, about 99.9% of the time, they have a "Converter/charger". Now, some, depending on how it's wired from the factory will, charge the chassis batteries too, when plugged in. Many, will not. So, the first thing you need to do is, determine what you have for a shore power, house battery charging system, be it a converter/charger or, INVERTER/CHARGER (usually only diesels). Once you make that determination, then you can start analyzing if it's wired for charging both sets and, if it's wired properly and, if it's malfunctioning or not. Good luck.Scott

does chasis battery charge while generator is on?

13 Replies

RoyB
Explorer II
Jan 16, 2015
Running the generator should be the same as connecting to shore power... Make sure you do not have any BATTERY DICONNECT SWITCHes engaged. Always handy to have a DC MULTIMETER around the RVs and in this case you should read the DC VOLTAGEs at the battery terminals. A fully charged battery should read 12.6 - 12,7VDC without the generator or shore power connected.

Switching to GENERATOR or SHORE POWER your battery terminals should jump to 13.6VDC or higher depending what charging mode your on-board converter/charger is doing.

We take our batteries very seriously and if they ever display DC VOLTAGEs at 12.0VDC or lower we know we are experiencing battery charging problems. Batteries that get discharged below 12.0VDC (appx 50% charge state) and not get re-charged back up to at least their 90% charge state will not perform well and in most cases will be required to be replaced. We can't afford buying batteries all the time...

IN your case if you are not seeing 13.6VDC or higher at your battery terminals when on Sore Power or Generator then you need to start looking for the Battery Disconnect Switch setting, in-line fuses or 12VDC circuit breaker between the converter/charger and the battery terminal, poor battery connection connection, or in the worse case a bad battery. Check the REVERSE POLARITY fuses in the Power Distribution Panel. Sometimes the batteries will boil out their fluids from being over charged and this also leads to battery failure.

I lost my first new battery in about three months of use before really starting a battery maintenance plan. The remaining three batteries I currently I have on my RV setup have been performing great now since 2009. Lessons learned for me...

Roy Ken
jplante4
Explorer II
Jan 16, 2015
What kind of coach? Most electrical setups charge all batteries when plugged in. Sounds like you might have a bad converter/charger. What's the voltage at the batteries? Does it change when you plug into shore power? Did you check all the breakers?
Cobra21
Explorer
Jan 16, 2015
In most cases the generator does charge the chassis batteries or house batteries. But normally the generator starts from these batteries also.
Brian

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does chasis battery charge while generator is on?

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