Is it okay to unhook my battery?

[SaadowGorl]

I am usually on the move while out in my vehicle, but was stationary for several days over the November holiday. I sleep in the vehicle and, have in the past, left the rear window/lift gate open with a bug screen over it. Usually the lights in the vehicle will auto shut off after 30 minutes (or so). This trip I was in and out of the doors a lot as I had a guest with me. Leaving the rear window open for ventilation meant that the lights stayed on for quite some time after opening the door to fetch something or to move things around. Initially this was not really a problem as the shorter days meant we needed the light anyway, but after a few days of this the battery died while out on BLM land. A helpful person gave me a jump and suggested that I turn off the interior light switch. I had no idea the dimmer switch could actually completely turn off the lights to avoid this issue, but also, unfortunately, this did not work; my interior light switch thing dims the lights, but will not actually turn off the interior lights in the vehicle. Long story short (too late), can I simply unhook the battery while stationary and then just reconnect it when ready to drive again? Would there be any potential problems with disconnecting the battery? This is probably a very silly question, but I ask for your patience as I have never learned any sort of vehicle know how.

 

[John61CT]

Sure in fact very common to have a disconnect switch wired so you don't have to use a wrench.

But you lose the time and radio memory, and some vehicle computers may need to "relearn" for fuel efficiency etc but no harm.

 

[Burbanlife]

Yes as stated above, install a battery disconnect switch and replace the bulbs with LED's

 

[Trebor English]

I do it all the time.  Every time a door opens or closes on my Ford Windstar 4 relays turn on for 30 minutes.  It is goofy.  

I got a battery disconnect switch at Harbor Freight.  The plan is you take the cable off the battery, put the switch on the battery where the cable was then put the cable on the switch.  It's a nice idea but the part of the switch where the cable goes is too small and the cable doesn't fit.  I highly disrecommend this Harbor Freight product.  

It is easy enough to loosen the cable clamp bolt and remove the cable from the battery.  Be gentle with the battery post.  

Some car computers don't like this.  They forget settings.  One thing I've heard they forget is how to manage the engine idle speed.  When you turn the wheel the power steering loads the engine and it needs more idle power.  The computer has to relearn how to do that.  There may be something about your specific vehicle that Google knows about.

 

[travlinman and wife]

If you are talking about only one light remove the whole light fixture and cut the wire and add a switch. switch on light comes on when door is opened switch off lights goes out.

 

[Weight]

such as this switch makes it easy. https://www.bluesea.com/products/9003e/e-Series_On_Off_Battery_Switch
I would recommend an upgrade to having a house battery to feed your lights and stuff not related to starting. I used to have a switch to disconnect the interior lights when the doors were open. That was part of the system to also switch the tail lights and brake lights to non function. Don't ask about those days. There is somethings with no statute. Any toggle switch could do that.

 

[highdesertranger]

is this your engine battery? if it is and you disconnect it you will loose all your computer memory. all your radio station presets, and you engine management computer will reset and might have to relearn all the settings. this might take 50 miles of driving at reduced economy and performance. highdesertranger

 

[SaadowGorl]

is this your engine battery?  if it is and you disconnect it you will loose all your computer memory.  all your radio station presets,  and you engine management computer will reset and might have to relearn all the settings.  this might take 50 miles of driving at reduced economy and performance.  highdesertranger

Yes, my engine battery. I'm not at all handy or knowledgeable when it comes to electronics or other mechanical/vehicle issues. Someone I knew had a secondary battery for running the radio, but I don't know anything about this. Even knowing where to start with installing a switch is well beyond my knowledge base, so dealing with the 50 miles of reduced economy/performance is probably what I need to deal with. Time/radio presets are an inconvenience rather than a problem; being stuck in the desert is of more concern

As always, thanks highdesertranger (and everyone else!); you've come up with some good answers for the many questions I've posed. I may not be able to do the long term easiest things, but knowing about workarounds is very helpful.

 

[frater secessus]

Many interior lights have a physical switch on them to control their behavior. Something like: LEFT = on, CENTER = on when doors are opened, RIGHT = off

 

[Weight]

take the bulbs out.

 

[highdesertranger]

what year, make, and model is your vehicle? highdesertranger

 

[Trebor English]

It depends on your vehicle.  Clipping wires, removing bulbs, replacing bulbs with leds, might make no difference.  In my van 3 computers come out of sleep mode and 4 relay coils get energized for 30 minutes.  With my van the only solutions are a battery disconnect, a bigger battery, or a solar charger for the engine starter battery  The disconnect means that I have to open the hood and turn the switch before I can start the engine.  The radio remembers the presets but needs the clock reset, no engine or fuel economy issues.  While the battery is disconnected the remote door unlock doesn't work.  

If you have a Ford yours may be similar.

 

[tx2sturgis]

Pull the fuse for interior lighting and possibly the fuse for the engine computer.

Then just use a good LED lantern inside.

Also it might be a good idea to buy a 'jumpstart' type power pack and keep it charged in case you need it.

 

[DLTooley]

Depending on how long the interior light was on this might be an early sign of a failing battery. If you get five years out of a battery you've done pretty well. FWIW I believe a solar system helps a tad bit at extending lifetime of a starter battery, especially if you are not a daily driver. Not sure how you'd verify that for sure.

 

[John61CT]

Using a Starter battery for anything but normal vehicle usage will reduce its lifetime, so within that context anything that keeps it topped up between trips will be a huge improvement.

 

[user 37446]

lots of thoughts, no one has suggested buying a marine battery for the starter battery usage - that will allow more of a draw without shutting off the whole system. Perhaps a small dash mounted or "toss it up on the hood or roof solar panel" with alligator clips to the battery to help deal with the losses. Definitely try to re-bulb the dome light(s), switching everything off daily may lead to other negative issues as HDR stated.

It's better to try and conserve than increase but sometimes you have to increase the ways to recharge.

 

[SaadowGorl]

It depends on your vehicle...The radio remembers the presets but needs the clock reset, no engine or fuel economy issues.  While the battery is disconnected the remote door unlock doesn't work.  

If you have a Ford yours may be similar.

Yes, I changed the battery after and noticed the same re presets and clock. I do have a Ford, so it sounds like a similar situation.

 

[SaadowGorl]

what year,  make,  and model is your vehicle?  highdesertranger

2000 Ford Expedition

 

[Trebor English]

Your 2000 Ford may be like my 1999 Ford.  Normally when you close the door the lights go out quickly.  Turn one on and it stays on for 30 minutes then goes out.  I replaced the bulbs with leds.  They all stay on dim even when turned off until 30 minutes are up.  The relay coils and the computers take an amp for 30 minutes.  Removing bulbs and replacing with leds makes little difference.  

I upgraded the battery to the biggest that would fit in the original location (group size 24).  I got one alleged to be deep cycle.  I got a 100 watt solar panel.  That stopped the battery killing.  I added a disconnect switch on the plus side so I can turn off the original van stuff leaving the solar and stuff I added still connected.  Only the switch is effective in stopping the "vampire loads" caused by the computers.