[MsNomer]

Last year after having been gone for 3 months, the van started right up. Today, after the van had sat at the dealers for 5 weeks (they were doing us a favor while we were out of the country), the van battery was dead. House battery is irrelevant--didn't have it yet the first time and this time it was disconnected.

Service guy said that with so many electronics that run all the time, the battery will go dead after 2-3 weeks, which doesn't fit with it having started last year. This is consistent with how many PM batteries were dead when we were test driving.

So--what's the longest time your PM has sat without a charge and it still started?

 

[RDinNHandAZ]

36 days, started right up. BUT....... I leave cars for 6 months regularly in AZ or NH and I always disconnect the negitive side of the battery or put a good quality trickle charger on them. Other wise they will be DEAD, DONE, FLAT, everytime. There is truth to what they told you but in my experience 2 months is usually OK, three a bit dicey. Heat is worse than cold too. DAHIK

 

[proeddie]

Welcome back!

DEAD, DONE, FLAT is not a good thing for a battery. Given the cam clip that holds the negative terminal on at the battery, it's pretty easy to disconnect the ground for a long term sit.

Betcha it would not be dead if the ground was disconnected.

On my Vette, they actually offer a "battery protection package" as an option.... fancy trickle charger with a Corvette logo on it... $100 (buyable for $60 without the logo) . Many Vettes sit for the winter here in New England.

Ed

 

[seapro]

My camper van battery gets low after 3 weeks sitting in its storage garage. I try to drive it every 2 weeks or I keep it plugged in and the house battery charger turned on. The Blue Sea ACR voltage controlled relay between the house and van battery systems works both ways and serves to keep both batteries up at a nice float voltage of about 13.3.

 

[Jumper]

Had a problem with an F-150 that sat so long battery went dead. The airbag system had an internal backup battery that would trigger the airbag even if collision severed battery power. This internal battery was kept charged by its connection to the starting battery. After the starting battery was dead for a certain amount of time the airbag internal backup battery failed. Its sealed inside a module & would no longer charge after being "DEAD, DONE, FLAT" for so long. As a result the airbag warning light flashed.

Found out there's a bit of a cottage industry selling refurbished airbag backup modules. New ones from FORD were quite expensive & had been on back order. In states with inspection a flashing airbag light will fail you & FORD charged a hefting fee just for doing the diagnostics.

 

[MsNomer]

If ours work that way, then disconnecting the battery is a bad thing? I'm concerned about leaving the van in a trailhead parking lot for several weeks. No plug-in possible.

Also, disconnecting the battery is a real PITA because of the full-coverage mat I have. How hard would it be to set up a remote switch?

 

[Steve]

I have a BlueSky ACR (automatic charge relay) that lets me start the vehicle from the house batteries if the PM's battery can't do the job - pretty standard setup. Haven't had to use it yet because with solar to keep my house battery (400amp lithium) charged the van can easily set 3-4 weeks without any problem.

 

[GapRunr]

If ours work that way, then disconnecting the battery is a bad thing? I'm concerned about leaving the van in a trailhead parking lot for several weeks. No plug-in possible.

Get one of these and leave it on your dash while parked. Just make sure it is plugged into an outlet that has power with the key off.

http://www.batterytender.com/Solar/5-Watt-Solar-Tender-Charger-With-Built-in-Controller.html

 

[MsNomer]

Do we have an always-live outlet?

 

[proeddie]

Do we have an always-live outlet?

I don't think so. Might need to add a cig lighter socket somewhere that is directly connected to the battery (via a fuse of course.) The additional socket would also come in handy to charge your cell phone (or whatever) when the van is off.

Ed

 

[wbullivant]

I have a BlueSky ACR (automatic charge relay) that lets me start the vehicle from the house batteries if the PM's battery can't do the job - pretty standard setup. Haven't had to use it yet because with solar to keep my house battery (400amp lithium) charged the van can easily set 3-4 weeks without any problem.

Steve
What kind of Lipo batteries do you have and what (AC) charger and solar charge controller do you use?
Thanks, Bill

 

[Steve]

Steve
What kind of Lipo batteries do you have and what (AC) charger and solar charge controller do you use?
Thanks, Bill

Most of the stuff for my original install came from AM Solar - http://www.amsolarrv.com - A Magnum 2000 watt Pure Sine inverter/charger and Blue Sky 2512iX-HV MPPT Controller, also got my panels from them.

Seven months ago I upgraded to a 400amp lithium bank (super pleased so far) also from AM Solar. I literally picked up the individual segments and assembled my own battery - don't know if they are shipping batteries yet. For what's it's worth, AM Solar has been testing lithium (for RV applications) since 2011 and seem to know their stuff.

Last month I upgraded to this Blue Sea ML-ACR - https://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A/FAQ - more robust than the more traditional isolator solenoid I had with my previous AGM batteries.

Hope this helps.

 

[jetmelt]

that solar panel will clip to the battery terminals in the engine compartment. That cable plug is a standard type and so you can buy extension pieces if the panel wont reach the roof. Also i posted a mod to make your usb live. It would work for the lighter too. just install an "add-a-circuit" to the fuse panel in the dash for a quick fix it comes with a fuse too

 

[keeponvaning]

I don't think so. Might need to add a cig lighter socket somewhere that is directly connected to the battery (via a fuse of course.) The additional socket would also come in handy to charge your cell phone (or whatever) when the van is off.

Ed

It's a simple mod to make the factory USB and lighter receptacles hot all ways. Simply cut the + lead to each and run another wire directly to the fuse block behind the small compartment on the left, bottom side of the dash (it's right over the obd port and held in place by a Phillips screw) don't forget a new inline fuse. I and several others have good write ups, with photos, in the archives on how to do it.

 

[DCHitt]

Running down the battery

Here is something to think about... According to one of the reps at the dealer....

The key fob has a security chip in it to keep the engine from starting unless the key fob is in the area.....

When the key fob is near the van the computers in the van get powered up.

So if you leave your van for long periods with the key fob near (like hanging on a nail in the garage). it will run the battery down because the computers are running.

Could this be the problem some of you are having?

 

[MsNomer]

That is an interesting point. Not the cause this time, but I will be careful about having the key in my pocket when working on it.

 

[keeponvaning]

I don't really think that is a big enough problem to worry about. I typically leave my keys in the ignition at home all day long, overnight if it's in the garage, and the last thing I would worry about is the key fob killing the battery. Over a year without ever starting it - perhaps but that is hardly a likely scenario for any of us!

 

[steve14]

I guess no one has measured the amperage draw when the van is not running directly from the battery? The battery in mine is huge and the engine is just a 3.6L so it should not take that much power to turn it over so there must be a significant power drain to kill the battery after just a month or so unless it was not fully charged when initially parked. The presence and detection of the key fob causing things to power on is an interesting concept, I was planning on adding a trailer brake controller which requires a couple of fuses to be added thus disconnecting the battery, if I think about it I will see if I can measure the power drain when disconnected with and without nearby key fob. I also would assume that reprogramming the radio might have some minimal effect but that might not be measureable, I just have the basic radio. Thanks to all about this issue, I will consider taking some precautionary measures, I don't want to replace that huge battery anytime soon.

 

[RDinNHandAZ]

If you park near power, a trickle charger for AGM is a cheap investment. I have them on all 7 vehicles, M/C, Tractor etc. Schumacher at WallyWorld is $29. Or a much more expensive solar battery maintainer from Battery Tender if you are not near a plug.
[ame]http://www.amazon.com/Battery-Tender-021-1163-Solar-Maintainer/dp/B004Q83TGO[/ame]
Then relax.

 

[Zyzzyx]

Aye, the Battery Tender Jr is great. My dad keeps it on his '64 Honda S600 while parked in the garage from October to April. It has a small and hard to get battery, but its still going fine after 5 years.