Chassis battery issue

[pokergeist]

1. A clamp-on ammeter with a DC A setting can measure DC current flow to/from your batteries and accessory cables. You can also check your voltages too. 2. A "Top Post Battery Disconnect" can be inserted between your negative battery post and the cable ... a few turns of the knob and you're set to go or stay. 2.5 The hygrometer was a good suggestion too.

I'll plug the Uni-T 210e Pro meter - a little pricey for casual use but I use mine all the time, and it always goes with the coach. It has DC mA capability - just orient the meter and zero it first.

Finally, with no access to shore power when the RV's in storage, I put a small fabric-backed solar panel in front of the windshield sunshade to counter the battery's self-discharge. G'luck!

[ruralIN]

I will first say that I have not read all the other replies, but I haven't seen anything along my first thoughts. On my older (2002 Granite Ridge) the steps are powered off the chassis battery. Since you say it never discharges while home (I presume just setting) but does while camping, are you using the steps on a regular basis or do you turn them off? If they cycle a few times a day, over time they would place a considerable draw on the battery. If yours aren't on the chassis battery that would be a different story, but mine cycle off the ignition switch, even if turned off. That prevents them staying down during travel.

[ruralIN]

Originally Posted by ljh684

Here's the Greyhawk manual page on this, the solenoid keeps the chassis battery isolated from the house system when the motor is not running. When the motor is running, the solenoid engages to charge the house battery from the engine alternator. if the chassis battery dies, you can temporarily connect the house battery to the chassis by pushing/holding the AUX START button to get the motor started. The AUX START button is not designed to charge the chassis battery, only to momentarily connect the house battery to the motor to get the engine started in case the chassis battery under the hood dies but the house battery still has a charge.

The Greyhawk lacks a Battery Isolation Manager (BIM), it's only present on the fancier Super C units these days. So that section of the manual doesn't apply, unless you install an aftermarket BIM like the Trik-L-Start.

Most people don't realize these Redhawk/Greyhawk units lack a BIM, so the chassis battery slowly dies from neglect. Since it is also a wet battery (not maintenance free) if people aren't checking the fluid with a hydrometer and putting in distilled water, it also dies from lack of maintenance.

If you aren't skilled with wet battery maintenance (keeping it charged/floating, using a battery hydrometer to measure electrolyte specific gravity, verifying and adding to fluid levels) get an AGM replacement for the chassis and at least keep it charged.

My solution is to take a short piece of single strand wire, put an alligator clip on each end and clip one to the house side cable and the other to the chassis cable effectively jumping the solenoid. That way the converter can charge the chassis battery. I never leave connected long as I never have had the chassis discharge significantly. Or you can buy the professional unit for about $45 to do the same thing.

[DonLegg]

The chassis battery in my 2016 Alante used to discharge on shore power. I found out the converter does not charge it. I bought a trickle charger, plugged it into one of my lighter outlets and plugged the 120v power cord into my 120v outlet on the passenger console. To monitor the charge I plugged a 12vdc digital meter into another lighter outlet. It reads 13.6v. I check the battery acid level occasionally. This has worked well for me for years, at home and camp. I don't know why your chassis battery charges at home but not at camp. ??

[pokergeist]

Originally Posted by DonLegg

... I don't know why your chassis battery charges at home but not at camp. ??

I wondered the same thing. A chassis battery voltage reading before and after applying shore power would tell us if there's been a charging mod to the OP's rig.

The consensus is that there is no ChBat charging though I would expect a decline in its voltage, especially since the battery has been deeply discharged. One difference is that the "Battery Disconnect Solenoid" is engaged when house power is on when camping. I don't see where that would make a difference unless somehow there's a power draw in the Power Step harness.

The wiring diagram for a Seneca only shows ChBat connections to the aux start switch, leveler solenoid, power cord reel motor, the power step harness, the BIM, and two items off-page (chassis related?). The BIM and perhaps other components are not standard equipment on his rig.

I know there are multiple solution to the problem, but I for one think it's good to know the root cause of the issue in case it can escalate into something worse.

[CBCOCRBO]

Originally Posted by Stone ART

Only while long term camping on shore power our chassis battery dies after roughly 10 days, with no apparent cause (ie: no lights or radio left on). When we are at home and plugged into shore power the chassis battery stays fully charged.
Potential short?

This may sound stupid to some but are you sure that the breaker is in the on position at the shore power pedestal. Most shore power pedestals have 30 or 50 amp receptacles as well as a 15/20 amp 110 volt outlet that are connected to a shut off breaker. Cheers, Rick

[Mike D.]

Originally Posted by SmokeyBear

You guys are making this too complicated. You are so concerned what Jayco did, or didn't do, and this solenoid and that inverter, etc., you are missing the obvious. Any battery will lose power over a period of time. Just ask any owner of collector cars.

OP: Buy a Battery Tender. When at the camp, hook it up as instructed and just leave it hooked up. It will charge your chassis battery and then maintain a trickle charge. It's a set it and forget it. Now enjoy your camping.

EXACTLY. we had same issue. All rv's have some parasitic draw. The manufacturers put a battery disconnect on the driver's floor on our Mercedez 3500 Jayco Melbourne 24L. Why? Because they can't solve the parasitic draw issue either! Do what he said. We did and have no problems.

[Bill Johnson]

I have one solar panel on the roof and it keeps the batteries charged all year otherwise I would need to plug into my house and and turn the disconnect on once a month in the winter to charge my batteries. My battery water goes down about 1/8 inch over a year

[Dmarcian]

I have a Greyhawk 27U on order. I have been told the standard solar panel will charge the house batteries first, and if they are full will then charge the chassis battery. Is this true?

[LongFella]

Originally Posted by Dmarcian

I have a Greyhawk 27U on order. I have been told the standard solar panel will charge the house batteries first, and if they are full will then charge the chassis battery. Is this true?

New to the forum and recently picked up an Odyssey 30Z...

Same question I have too.

Ours has the 190W Solar, additional house battery, but I am not sure if the solar is wired to the chassis battery too.

Reading the manuals, the solar can hit two batteries... so that leads me to believe the two batteries it charges are the two house batteries and NOT the chassis...

Still reading and figuring it all out

[Bill Johnson]

Originally Posted by LongFella

New to the forum and recently picked up an Odyssey 30Z...

Same question I have too.

Ours has the 190W Solar, additional house battery, but I am not sure if the solar is wired to the chassis battery too.

Reading the manuals, the solar can hit two batteries... so that leads me to believe the two batteries it charges are the two house batteries and NOT the chassis...

Still reading and figuring it all out

I got rid of my Jayco and bought a Thor, I didn't know until I put my meter on the chassis battery that it was charging it and the house batteries. I like it because the disconnect switch can be off all winter or whenever the motorhome is not being used. I don't now how Jayco has theirs set up

[doghauler]

I have the same set up on my 2022 29MV. The solar charger considers the 2 house batteries as one because they are connected together. Once the house batteries are charged by the solar panel it switches current to charge the chassis battery. You should be able to see this on the app associated with your solar charger.

[LongFella]

Originally Posted by doghauler

I have the same set up on my 2022 29MV. The solar charger considers the 2 house batteries as one because they are connected together. Once the house batteries are charged by the solar panel it switches current to charge the chassis battery. You should be able to see this on the app associated with your solar charger.

After speaking to our Dealer, he mentioned our 2023 Odyssey 30Z is wired to charge the two house batteries only and not the chassis. They said if the chassis battery dies, holding the AUX button left/low of the steering wheel will start the engine using the house batteries.

Wha t app are you referring to? We have the basic panel that shows B1 and B2 and Solar... showing volts, etc... but I do I know B2 refers to the chassis battery or 2nd house battery??

[ljh684]

More on the house battery and its charging circuitry. Here's a photo of the Progressive Dynamics PD9200 series 120V shore power to 12V converter in a 2019 Greyhawk. No solar on the roof, people with solar have additional charge management equipment.

The newer PD9200 series has the "Charge Wizard" integrated per the label. The older PD9100 series does not. If you pull out the center drawer between the two closets in the bedroom, you can see down in there and get your converter model number. If you don't have a 9200 series converter, the manual recommends leaving the camper unplugged from shore power for long-term storage, and only plugging in once a month or so for a bit to charge the house battery and avoid over-charging.

If you're going to be camping for many weeks on shore power --- say 8 weeks of campground host duties like the OP --- Precision Dynamics sells the Charge Wizard module as a cheap add-on to the PD9100 series converters. Pick one up and have your dealer install it to avoid over-charging the house battery.