Question Dead Chassis Batteries in a Few Weeks?

[Jabber Jaw]

In my relatively short time of RV ownership, what I've always done, when at home, is use an adapter, & plug in to a 20 amp outlet, via extension cored. The coach is under cover, but about 80' from the pool shed. This has worked well, keeps batteries charged, and allows me to use lights, fireplace, TV's, in the coach, and no issues. I do not try to use anything with a relatively high amperage draw.
If we stay here, & don't sell & move to Florida, I will run a 50 amp line to the RV port and install a 50 amp plug.

 

[AbdRahim]

I wouldn/t leave my car for a year without disconnecting the battery. I don/t even know if 3 months is wise. Now when it sits for a month, I leave it on a Battery Tender.Remember, lead acid batteries should never go below 50%. My SUV gets there pretty quick if not started over a long period of time. MH is always plugged in.

 

[Old-RV'er]

Hmm, here is story. Got to RV park close to home on 16th Feb. Emptied coach over next day or so. Put coach into storage on Monday 17th and turned off master switch on (PS Side console) and chassis master switch. Next day went over to winterize, so started generator, immediately went into Absorb Charge mode (had on inverter so could run fridge and such) realized that was not needed if genset was providing a/c power. Took two days to winterize coach, since factory system did not work, had to bypass that and use Water Pump Direct, anyway got it done. That took about 2-3 hours, batteries stayed in absorb. So Sunday last, went over started genset to charge batteries, left them running for 3 hours or so, came back, still in absorb level. Refer was off, Microwave clock only, inverter off. all lights, radio, etc. off. So shut down genset, and then check water level in batteries. None of them was below plates in cells, not right at the tops either, so put distilled water in cells which looked low. Going back on Saturday next to run genset most of day to see if system charges up. Nothing is on, but like you folks, think there is more directly tapped into battery's, both chassis and house than those three things listed above. Oh I have 500 Watts of solar on the roof and the little 10W one as well. The solar controller during the day shows system has voltage being produced, but those panels are mostly under cover, so not even close to direct sun (that is when the sun shines), so far rainy and cloudy for most of time at home. This however is about like the other MH we had and it's state of battery charge in storage without shore power being available. I am thinking I need to take it camping about once a month to get all the systems exercised for a night or so. I don't like winter camping in the cold period. Oh, I need to clean one terminal on house system, rest are good.

Oh, when we leave for extended period, I remove batteries from car and tractor and store in basement in crawl space which is heated. Both started right up after reinstalling them.

 

[Joe Dutchstar]

Some draws are intermittent so you have to be patient.

 

[Old-RV'er]

Ok - To update. we periodically have severe cold waves come through. I have 500 watts of solar on the roof, but under cover so it's not doing a lot, some but not a lot. The following parasitic draws are on the chassis batteries: 1) Front Electric Step; 2)Door and Compartment locks-lights in all those compartments as well: 3)Genset starting power. Additionally, I know the ECM for the main engine is draining some, otherwise it would not run correctly. I think it's way more than .1A. I try to go over and start Genset and charger her up about every 4-6 days. There is no shore power available to me there. About once month take it up the road 10 miles or so to work everything a little. I also run heat pumps or the Oasis System to keep all that working. If I wait longer than week, I get low battery warning on the Dash display when powering up the coach, key on, after all the warnings buzz, gauges cycle, etc. So I have shortened up my interval between charging times to 4-5 days instead of over week. This seems to work best.

 

[Joe Dutchstar]

Another method

 

[Chuggs]

Well...if you guys are right —- a lot has changed since 2016...or perhaps the DSDP is that much different from the VTDP. That could be. Just wonder why the Newmar Engineers would depart from some form of standardized wiring process, for things that are common.

The handout below came in my Black Bag. I have highlighted things that are “Constant Battery Power”. IMPORTANT Note: These are on the HOUSE battery system...not the CHASSIS.

I have a Freightliner Chassis...and according to the EZ-Wiring from the DTNA website...(also attached below) you will see the only thing the Chassis Disconnect does it cut the two 2/0 power lines that terminate under the drivers seat in the basement compartment. So all of those circuits are de-powered. There are other things attached to the two Group 31 batteries not shown in the schematic I attached...so there are things that continue to be connected even with that disconnect switch thrown. There also should be a small red wire with an inline 7.5A fuse...labeled solar. I decided to check mine. It had blown. So for who knows how many years...that 10w ZAMP solar panel hasn‘t done anything but create wind drag. While I had the fuse out...I checked the Voc and it was about 17v open circuit. And attached to the batteries...about 0.3 amps of current going into the batteries. I replaced the fuse...so hopefully it’s doing something now. I’ll check it again when I do my annual service work in February to see if it’s still intact. I’m interested in pulling that solar panel up...to see if I can fish some new wires thru the existing loom. If I can...I’ll remove it and install a 200w panel and SmartSolar MPPT 75/15 controller. Then I know the Chassis Batteries will maintain themselves. It will also make it easier in the future to split my systems for LiFePO4 House Batteries in the far off future.

It seems odd the technician would list three things...that in a lot of coaches are not connected to the chassis batteries at all.

 

[Joe Dutchstar]

And another way to test for parasitic draw

 

[Chuggs]

I want one

 

[Old-RV'er]

Me too, wonder what will show up if I do that to MH. Gonna have to wait until wx improves. Cold/snow soon.

 

[flyboy013]

I still have a chassis parasitic draw such that the battery will be down to 12.4 in about 3 days. It hasn't been much of a problem since the coach is plugged in nearly 24x7. Reading these posts makes me want to investigate the problem once again. I'll be in warm weather next month and it will give me a good opportunity to tackle the issue again.

Other than using the terminal imaging camera to find a device that's putting off some heat, are there any other good uses for it? Also if the "hot" device in behind the instrument cluster or tucked away somewhere, I would expect the effectiveness of the camera to be someone limited. Figure I'll try the clamp meter along with testing the voltage drop across the fuses.

 

[Joe Dutchstar]

If you are using a flooded acid battery,

Home 3 - Progressive Dynamics

The Mighty Mini Compact All-In-One System offers an AC/DC Power Distribution Panel and Inteli-Power Converter with Charge Wizard battery charging technology.

www.progressivedyn.com

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a lead acid battery will self-discharge at a rate of approximately 4% a week. A battery with a 125-amp hour rating would self-discharge at a rate of approximately five amps per week.

 

[Chuggs]

Interesting....

The tech paper put out by Interstate Battery for out GC-2 have charge recommendations per cell. So, wired in series to make 12v you have six cells.

They also use a different temp reference for thier charge parameters than the MS2812 Inverter uses so, I adjusted them.
Magnum



Absorb Voltage 14.51v

Float Voltage 13.43v

Equalization 15.65v

Temp comp...default -5mv/°c/cell

The “Charge Wizard” doesn’t really come close. What they are calling equalization is what the Magnum does everyday when it goes into “Absorb”...