Coach/engine batteries on Seneca

Joe1mc · 03-13-2016, 04:57 PM

On a Seneca which batteries are the coach batteries and which ones are the batteries that turn over the engine? Also, if I use a battery tender will it keep all the batteries charged. If If I just plug the coach into 110 with the disconnect switch in the off position, will the batteries charge that way?

Robbbyr · 03-13-2016, 05:25 PM

On the newer Senecas the coach batteries are the four batteries in the external compartment right behind the cab on the driver's side. They are located on the slideout tray in that compartment. Very easy to access and service.

The two chassis batteries are located under the cab floor more or less directly under the driver's seat. You access the batteries by removing the panel above the driver's step held on by 3 screws. Driver's door has to be open to get to the screws. These batteries are much harder to get to when they need to be changed.

The coach batteries charge off the converter when plugged in to shore power, the converter has 3-stage charging so it is safe to keep them plugged in. Older converters were not as kind to batteries and would eventually overcharge them if left on continuously. Not a worry today, but you still do need to take proper care of the batteries.

I have a Battery Tender trickle charger with a cigarette lighter adapter. When parked and the coach is plugged in, I plug the Battery Tender into a 110-volt outlet inside the coach and the output plugged into the dash cigarette lighter outlet. That keeps the chassis batteries topped off when parked.

A single trickle charger will not keep all 6 batteries charged since the chassis and coach batteries are electrically isolated from each other when the engine is off. Even if they were tied all together most trickle chargers would probably not have enough output to keep 6 batteries charged up.

Joe1mc · 03-13-2016, 06:18 PM

Thank you for suck a speedy reply! You have answered all my batterie mysteries and have set my mind at ease. When I did coach walk through I was never told about the engine batteries and there location. I'll hook a battery tender to the engine batteries to keep them charged.

Grumpy · 03-13-2016, 06:23 PM

Unless JAYCO downgraded, the converter also charges the chassis batteries when on shore power. That is how it was set up on the KODIAK version.

Robbbyr · 03-13-2016, 06:30 PM

You are welcome!

When stored I just use one regular extension cord to plug in my unit using a 50-to-30 amp adapter then a 30-to-20/15 amp adapter. Obviously I cannot run any significant electrical loads only using an extension cord, but this works fine to feed power to the onboard converter and the Battery Tender I plug into an interior outlet.

It is a 20-amp circuit I plug into at my storage site and the breaker has never blown (yet!). One extension cord to the unit but all batteries being maintained continuously.

Joe1mc · 03-13-2016, 06:32 PM

While stored, and plugged in to 110 do you keep power to your coach or do you push the disconnect button ? So you're saying just plugging the unit into 110 will keep all my batteries charged!

Robbbyr · 03-13-2016, 06:35 PM

Quote:

Originally Posted by Grumpy

Unless JAYCO downgraded, the converter also charges the chassis batteries when on shore power. That is how it was set up on the KODIAK version.

I had hoped that was how mine was wired, but when I plug in my unit to shore power I only get a voltage rise on my coach batteries, not my chassis batteries. So I went with a Battery Tender plugged into an interior 110 outlet feeding into the dash cigarette lighter socket. So far so good.

Any other newer Seneca owners find that their chassis batteries do indeed charge off of the converter? If they do, I have some sort of problem I will track down!

Grumpy · 03-13-2016, 06:36 PM

Quote:

Originally Posted by Joe1mc

While stored, and plugged in to 110 do you keep power to your coach or do you push the disconnect button ? So you're saying just plugging the unit into 110 will keep all my batteries charged!

I never hit the disconnect when on shore power. Only turned it off when the coach went in for service.

Grumpy · 03-13-2016, 06:44 PM

Quote:

Originally Posted by Robbbyr

I had hoped that was how mine was wired, but when I plug in my unit to shore power I only get a voltage rise on my coach batteries, not my chassis batteries.

There should be another controller in the coach battery compartment and it keeps a trickle charge on the chassis. You may not see a voltage rise. I never checked the voltage, but the batteries never went dead in 6 years, even when sitting all winter while on shore power.

Robbbyr · 03-13-2016, 06:46 PM

Quote:

Originally Posted by Joe1mc

While stored, and plugged in to 110 do you keep power to your coach or do you push the disconnect button ? So you're saying just plugging the unit into 110 will keep all my batteries charged!

My converter charges the coach batteries even with the coach master disconnect switch turned off. And all the 110-volt outlets are "hot" whenever plugged in to shore power regardless of the status of the coach master disconnect.

I shut off the master disconnect whenever my unit is stored or not in use to cut down on any parasitic 12-volt drains. I accidentally left a compartment light on once and nearly drained the coach batteries when I also forgot to kill the master. Shutting off the master cuts all that off.

The master disconnect does have to stay "on" to keep the refrigerator running on shore power (110-volts) or propane. Shut if off and the fridge shuts down!

Robbbyr · 03-13-2016, 06:57 PM

Quote:

Originally Posted by Joe1mc

While stored, and plugged in to 110 do you keep power to your coach or do you push the disconnect button ? So you're saying just plugging the unit into 110 will keep all my batteries charged!

If what Grumpy says is indeed the case on the newer Senecas, then just plugging into shore power would keep all batteries charged. I will have to investigate whether there is a link (isolator) between the coach batteries and the chassis batteries. If there is, I don't think mine is functional.

Mnwelsh · 03-14-2016, 07:36 AM

Read this. It explains a lot about battery charging. It's in your

http://www.precisioncircuitsinc.com/...anual-RevA.pdf

Mr.Oz · 03-15-2016, 09:53 AM

Quote:

Originally Posted by Robbbyr

If what Grumpy says is indeed the case on the newer Senecas, then just plugging into shore power would keep all batteries charged. I will have to investigate whether there is a link (isolator) between the coach batteries and the chassis batteries. If there is, I don't think mine is functional.

I checked mine by turning the ignition on and reading battery voltage on the dash. 12.8 with the coach unplugged and 14.1 with it plugged in so mine is charging all the batteries. That said when mine is in storage I use two battery tenders to prevent overcharging. I also turn the master switch off.

Robbbyr · 03-15-2016, 10:01 AM

It seems I need to check my system since I don't get a rise on my voltmeter on the chassis batteries. Mnwelsh has certainly given me the starting point to troubleshoot, thanks!

Joe1mc · 03-15-2016, 10:17 AM

There is a voltage indicator in my coach control panel, it reads 12.8 is that the coach battery voltage? What exactly do I have to watch on that voltage indicator, if voltage goes down while not plugged in; then I should turn on my generator until it come back up to 12.8 ?

Robbbyr · 03-15-2016, 10:35 AM

Quote:

Originally Posted by Joe1mc

There is a voltage indicator in my coach control panel, it reads 12.8 is that the coach battery voltage? What exactly do I have to watch on that voltage indicator, if voltage goes down while not plugged in; then I should turn on my generator until it come back up to 12.8 ?

My Seneca's coach batteries originally were only "monitored" by the same device that told me my tank levels. Very imprecise. So I installed a real voltmeter so I could have a better idea where they were. Newer unit must have something different if you are able to read actual voltage.

If unplugged boondocking I will use the generator when the coach batteries drop to around 12.2 to 12.3 volts to prevent over-discharge. That reading is taken with minimal to no load drawing them down. I shut off my inverter and make sure the furnace isn't actually running when I take the reading.

Mountain Cajun · 03-16-2016, 07:13 PM

My 2016 HJ converter trickle charges both coach and chassis batteries according to dealer at walk around. I did see 4 batteries in the slide out compartment all connected together and said this can't be chassis batteries too. I'll have to look under drivers seat for them. Been driving too much to really look but I figured they were somewhere.

Robbbyr · 03-16-2016, 07:29 PM

Quote:

Originally Posted by Mountain Cajun

My 2016 HJ converter trickle charges both coach and chassis batteries according to dealer at walk around. I did see 4 batteries in the slide out compartment all connected together and said this can't be chassis batteries too. I'll have to look under drivers seat for them. Been driving too much to really look but I figured they were somewhere.

That is where the pair are hiding, have to remove the panel at the top of the driver's running board/fuel tank cover to get to them.

Grumpy · 03-16-2016, 07:37 PM

Quote:

Originally Posted by Mr.Oz

That said when mine is in storage I use two battery tenders to prevent overcharging. I also turn the master switch off.

The converter has the built in "Charge Wizard" so the batteries won't overcharge on shore power.

Sam · 03-19-2016, 03:13 PM

I checked my chassis batteries without being plugged in and my dash reading indicted 12.2 volts. Plugged in after several hours it still read 12.2 volts. The master switch was always off. So I assume that I am not charging the chassis batteries when plugged in.

Rob, I like your idea about using a Battery Tender plugged into the cigarette lighter. As you can see, my Seneca is same as yours.

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