Coach Battery Disconnect?

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Coach Battery Disconnect?

May 17, 2020, 03:24:16 pm

Is there a coach battery disconnect that will prevent the batteries from being drained during short term storage?

I ensured the boost switch was off, the power disconnect just inside the coach door was off and turned off all breakers, but the heart Freedom 25 inverter continues to run and drains the coach batteries.

Short of disconnecting the battery cables, is there a way to disconnect the batteries?

BTW, the coach has a solar panel, but I know nothing about it.

Re: Coach Battery Disconnect?

Reply #1 – May 17, 2020, 03:27:07 pm

Turn OFF the inverter! It draws down the batteries with a small load while in "stand-by mode".

There are also parasitic loads on the chassis battery from the memories for computers, radio's, etc.

How long are we talking about for "short term"?

Re: Coach Battery Disconnect?

Reply #2 – May 17, 2020, 04:03:23 pm

Short term as in a week.....it has only been a week since I installed new batteries and today they were completely drained.

I am pretty certain I had the inverter turned off, but just pulled out the manual and it suggests there might be a remote control...a previous owner circled that section,.

I do not recall seeing one, but will go on a search. Manual says leave the switch on the inverter in the off position if there is a remote. I assume that means even though I have the switch in the off position, the inverter is being controlled by the remote panel.

Re: Coach Battery Disconnect?

Reply #3 – May 17, 2020, 05:27:25 pm

I don't know the truth, but this is what I think (the documents are incomplete): The inverter can be turned on either by the switch in the bay where it lives (smaller through-bay) or using the "remote" located across the hall from the refrigerator. Make sure the inverter light is off on the remote (upper left, I think) and the switch off in the bay. That inverter draw is a battery killer.

Re: Coach Battery Disconnect?

Reply #4 – May 17, 2020, 06:25:21 pm

The only way to actually disconnect the start batteries is to remove the negative battery cable or to add an adequately sized battery switch. Marinco makes a good one. Blue Sea makes one as well.

BEP Marinco Pro Installer EZ-Mount On/Off Battery Switch

Re: Coach Battery Disconnect?

Reply #5 – May 17, 2020, 06:27:53 pm

Conventional batteries will self discharge in a couple of months in summer with temps 90 degrees or above. AGMs less if "pure lead" type. Lead acid batteries can go all winter and still be at full voltage come spring.

Quote: As lead acid batteries absorb high heat, chemical activity in the battery accelerates. This reduces service life at a rate of 50% for every 18°F (10°C) increase from 77°F (25°C). If a battery has a design life of six years at 77°F (25°C), and the battery spent its life at 95°F (35°C), then its delivered service life would be three years. This dramatic reduction in delivered service life can cause older batteries to suddenly fail in high heat because the accelerated failure rate occurs without warning.

So, you really need to keep some kind of trickle charger on the batteries during summer or their lifespan will be shorter.

Pierce

Re: Coach Battery Disconnect?

Reply #6 – May 17, 2020, 06:34:03 pm

There are only two ways to make sure that unknown loads can't run a battery down. The cheap way is to disconnect the batteries. If this is a one-time thing, that's probably the way to go. For a few dollars, though, you can add a switch. Then you can disconnect the batteries as needed easily and safely. If you are going to be doing this often, I'd suggest the switch.

IF (and that's a big IF) there are now loads on the battery, I would think that a healthy battery bank ought to last a week before going flat. If your batteries are reasonably accessible, you might try putting an ammeter in the circuit and see what sort of draw you have when you think everything is turned off. Might be interesting.

Re: Coach Battery Disconnect?

Reply #7 – May 17, 2020, 08:08:55 pm

I have three GEL 8Ds and three AGM 8Ds that I use for solar energy storage and backup power. In December they were fully charged to about 12.7v resting. I disconnected the batteries from charging and from all loads. When we got home in May they were at 12.5 to 12.6v. They were in my shop at 50 degrees.

One of the GEL batteries is dated from 2000. The other GEL batteries are from 2014. The three AGM batteries are from 2011.

Re: Coach Battery Disconnect?

Reply #8 – May 18, 2020, 08:44:05 pm

If you have the original heart inverter the switch on the inverter should be turned off and then the inverter is turned on and off with the heart panel inside the coach.

Re: Coach Battery Disconnect?

Reply #9 – May 18, 2020, 10:19:15 pm

How'z about you pull off the ground cable to the battery bank? Free.

Re: Coach Battery Disconnect?

Reply #10 – May 19, 2020, 08:14:36 am

I use a simple, high quality, 600 amp, disconnect that I installed with a short extention cable, see picture, and disconnect below.

With new AGM batteries, I've twice gone six months in storage, with no problem. When installing the switch with extention, I had local Interstate Battery distributor make a new connection cable, as the original looked pretty abused.

Amazon.com : Battery Switch HD ON/Off : Boating Battery Switches : Sports &...

Shared album - John Lewis - Google Photos

Not having any additional needed length of neg & pos cables, mine are original, I connected the two batteries as they came, OEM. At 30 months from install, tested great, both AGM batteries still were at 12.9 volts at overnight resting voltage. Spec for new AGM battery is to loose 2--3 % per month when stored, starting with full 100% charge. With corona virus issue this will now extend my storage to + 8 months. I will update in July.

"To join batteries in parallel, use a jumper wire to connect both the positive terminals, and another jumper wire to connect both the negative terminals of both batteries to each other. Negative to negative and positive to positive. You CAN connect your load to ONE of the batteries, and it will drain both equally. 24 Feb. 2020" from BatteryStuff.com

Re: Coach Battery Disconnect?

Reply #11 – May 19, 2020, 11:29:42 am

All,

I ran into the same problem lately with our rig stored longer than normal. I turned the house battery switch off by the door, the inverter was off (normal position) but the panel was still lit. I was under the assumption when we purchased the rig that the switch by the door was a battery disconnect switch but it must be further down the line allowing other devices to still draw power.

At this point I am assuming I need to install a battery disconnect switch in the battery bay the same as on my boats. Is this what others have done?

David

Re: Coach Battery Disconnect?

Reply #12 – May 19, 2020, 12:00:09 pm

Inverter is directly connected to the battery. No off other than the panel "off" There may be a panel off "power saver"

Re: Coach Battery Disconnect?

Reply #13 – May 19, 2020, 12:13:25 pm

Quote from: Familyrig – May 19, 2020, 11:29:42 am

All,

I ran into the same problem lately with our rig stored longer than normal. I turned the house battery switch off by the door, the inverter was off (normal position) but the panel was still lit. I was under the assumption when we purchased the rig that the switch by the door was a battery disconnect switch but it must be further down the line allowing other devices to still draw power.
At this point I am assuming I need to install a battery disconnect switch in the battery bay the same as on my boats. Is this what others have done?
David

Even with battery switches installed in both banks, you can expect a slow discharge from the moment you turn off the coach. While the batteries will hibernate nicely in winter, summer high temperatures accelerate the discharge process. As Bob posted, once batteries have been flattened, they are not the same after that. One complete discharge may be enough to ruin some. So check them frequently and keep a trickle charger on both banks. Keeping 13 to 13.5 volts going into the batteries at all times will make sure they live out their expected lives and even exceed the average.

This is a reason for most RV owners to avoid the high priced batteries. As much as their wishful thinking goes, they will forget, lose interest, suffer a power failure, etc. and the batteries will be flattened and need to be replaced. Here in Northern California, high winds and hot temperatures in the summer mean the evil PG&E utility company (not kidding here) will turn off the power for days and then will spend even more days inspecting the lines for damage. Home owners will not only have to plan for power backup to keep all their food from spoiling, well pumps operating but can't forget their RV in the driveway.

Pierce

Re: Coach Battery Disconnect?

Reply #14 – May 19, 2020, 12:22:45 pm

Good info. Especially the forgetting idea. Only way not to make a single mistake is an auto combiner and a solar panel system if outdoors. Every new coach comes with one.

Killed 2 sets of batteries before I fixed the issue.

Easy install where the isolator is/was. Magnetic latching. No power draw

Re: Coach Battery Disconnect?

Reply #15 – May 19, 2020, 02:08:43 pm

Thanks guys for the info. The motorhome stays up at the lake all summer with hookups so the heat is not an issue. The downtime during the winter is my main problem. After our Thanksgiving trip to the Aptos we normally only due 1 or 2 crabbing trips then stop any use until spring break. We have inside storage but no power, which eliminates the solar option. I think I will install a battery switch to isolate any potential load for now & try to get it out more often to stretch it's legs during the winter.

David

Re: Coach Battery Disconnect?

Reply #16 – May 19, 2020, 08:30:49 pm

How about an outside solar panel wired to the coach?

Only other way is to pull the batteries and take them with you or to a place with power?

Re: Coach Battery Disconnect?

Reply #17 – May 19, 2020, 08:31:15 pm

Quote from: Twig – May 18, 2020, 10:19:15 pm

How'z about you pull off the ground cable to the battery bank? Free.

or, isn't there a simple, inexpensive knife n slot thing, to attach onto the ground post, rather than a fancy $60 rotary switch?

Re: Coach Battery Disconnect?

Reply #18 – May 19, 2020, 09:25:06 pm

Quote from: Mogan David – May 19, 2020, 08:31:15 pm

or, isn't there a simple, inexpensive knife n slot thing, to attach onto the ground post, rather than a fancy $60 rotary switch?

$14 delivered is not going to break the bank. 12V Battery Isolator Disconnect Rotary Switch Cut On/Off For Car RV ATV UTV...

Pierce

Re: Coach Battery Disconnect?

Reply #19 – May 19, 2020, 09:41:07 pm

Don't use this on the start battery circuit tho...it'll let the smoke out. Starter pulls 500+ amps.

Quote from: Pierce & Gaylie Stewart – May 19, 2020, 09:25:06 pm

$14 delivered is not going to break the bank. 12V Battery Isolator Disconnect Rotary Switch Cut On/Off For Car RV ATV UTV...

Pierce

Re: Coach Battery Disconnect?

Reply #20 – May 19, 2020, 11:15:34 pm

House batteries never see anywhere close to that. The boost solenoid (Cole-Hersee 24213) is only rated 200 amps max. For the $14 you get 300 amps 300A 12-48V Battery Isolator Disconnect Switch Power Cut Off On for Marine... These switches have well over 1000 amps for 10 seconds starting.

Pierce

Re: Coach Battery Disconnect?

Reply #21 – May 20, 2020, 12:02:06 am

China products have been known to have both meaningful ratings and totally overstated ratings, for the disconnect switch $60 with a 600 amp rating, compared to $15, for this item I'll stick to a brand name, which just may have lower resistance, and higher quality construction. Just the fact the more expensive one is spark proof rated for a marine environment tells me there is a big difference in construction.

I'm all for saving money, but not on an item that if it fails, may cause your engine to stall, taking away your power steering, till you can pull over safely.

PS. If this scenario ever happens to you, (engine stalls, causing loss of power steering), start your generator quickly, which with a separate ground may allow you to re-start your engine. This scenario primarily would be from a shorted out chassis battery, not a failed disconnect.

Re: Coach Battery Disconnect?

Reply #22 – May 20, 2020, 12:29:15 am

If you really need to make sure you do not end up with dead batteries this and a sun powered voltage source is pretty hard to fail.

ML-ACR Automatic Charging Relay - 12V DC 500A - Blue Sea Systems

1450 amps for 30 second cranking

Re: Coach Battery Disconnect?

Reply #23 – May 20, 2020, 01:28:17 am

Jack,

Since one of the members didn't want to spend much, I just found a switch at a cheap price. Not a recommendation, but a link.

We always had a Cole Hersee M750BP or matching CH on all of our apparatus. FYI: Cole Hersee has most of their products made in China or ROC now.

Chinese SUVs are starting to take a significant share of the market abroad. I saw one without the name badge here last month. A big surprise.

Pierce

Re: Coach Battery Disconnect?

Reply #24 – May 20, 2020, 03:37:09 am

Quote from: Caflashbob – May 19, 2020, 08:30:49 pm

How about an outside solar panel wired to the coach?

Only other way is to pull the batteries and take them with you or to a place with power?

Unfortunately we pay for storage at a large facility or I would install outside solar. I have been thinking about pulling the batteries (we do this with our boat) but with my back these ones are extremely difficult.

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