Disconnect battery when parked?

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SlantedMark4

SlantedMark4

'74 Valiant 225 /6
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This might sound weird and I might get laught on, but I'm just wondering if I'm the only one with this "fear".
I always disconnect the battery (I have installed a battery dosconnect switch) when I park my '74, even on meets. I'm worried about a fire caused by the battery. I mean, if I turn off the car and the battery is connected, there's still some load on the wires, right? I just think due to the age of the wiring, isn't it possible to cause a fire when the battery isn't disconnected?
I have to say, I've had two incidents with the wiring that almost ended in a fire (broken original amp. meter that ended pretty bad and a blown fuse)
 
On an old car, when the ignition switch is turned off, then everything is really turned off. There is no draw on the battery- things are OFF! New cars are different. With multiple computers and loads of sensors and electrical stuff there is always something ON, maybe on a reduced level but still ON! This is why battery life on new cars is reduced.
 
Murray said:
On an old car, when the ignition switch is turned off, then everything is really turned off. There is no draw on the battery- things are OFF! New cars are different. With multiple computers and loads of sensors and electrical stuff there is always something ON, maybe on a reduced level but still ON! This is why battery life on new cars is reduced.
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I don't think that is 100% true. If what you are saying then how would one turn on the four way flashers, lock the car on the side of the road and proceed to get help if say you ran out of gas ?? The interior light, horn, cigarette lighter, headlight and possibly a few other accessories will operate without the key in the ignition. So to answer the OP's question, it's not a bad practice to have a quick disconnect switch and to use it. Just my thoughts.
 
I have had a battery disconnect in my trunk for a long time. I shut it off more for parasitic slow drain, than I do fear of fires. I also agree that even though these old cars don't have security systems or fancy radios draining the battery, there are many things as noted above that still get some power even when "off". Thats why I disconnect it, especially when I know it'll be sitting for a while.
 
Murray said:
On an old car, when the ignition switch is turned off, then everything is really turned off. There is no draw on the battery- things are OFF! New cars are different. With multiple computers and loads of sensors and electrical stuff there is always something ON, maybe on a reduced level but still ON! This is why battery life on new cars is reduced.
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This is not true. Several circuits are still "hot" and if they develop a fault they can cause trouble. On Mopars, horn, brake lights, hazard flashers, dome lights, glove box/ trunk/ underhood light and the output circuit of the alternator.
 
On older cars with no computer, and with no modern radio with "keep alive" for setting the programming, there is NO downside to a battery disconnect. If you build it so the trunk, etc, must be raised, it is a decent aniti theft provision.
 
Murray said:
On an old car, when the ignition switch is turned off, then everything is really turned off. There is no draw on the battery- things are OFF! New cars are different. With multiple computers and loads of sensors and electrical stuff there is always something ON, maybe on a reduced level but still ON! This is why battery life on new cars is reduced.
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The ammeter is always hot.
 
thesiren74 said:
I disconnect the positive cable after every time I put them in the garage.
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And that is bad practice. Positive side is more likely to arc than the ground side. Lead acid battery vapors are flammable/explosive.
Almost every procedure in a FSM first states, "Remove negative battery cable".
I have a modern stereo with programmable channel memory in my 67. I still disconnect neg' cable every time I turn it off. I just shove a cd in the jukebox anyway. No need to program channels.
If you have a factory clock in your car, disconnecting battery is a bad plan for a totally different reason. No need to go into that here I suppose.
 
I’ve been thinking of a battery disconnect for my Scamp, primarily for when I rarely drive it during the winter.

What battery disconnects are you using? When I read reviews on some, half of them indicated they were crap (ie: broke or didn’t fit). Post up yours if yours so I can get a good one!
 
I think to disconnect the battery is good cheap insurance. This helps to extend the life of the battery and any malfunctioning while parked for a long time.

Here’s the battery disconnect switch I’m using;

Moroso 74101 Battery Disconnect Switch 84663741012 | eBay

IMG_6330.jpeg
 
Haven't tightened the bolt on a negative cable in over 40 years. Terminal in place, then push and twist. Never an issue and always removed as soon as the cars are parked in the garage and easy to quickly remove in an emergency.
 
I have a friend with a vacation house in Hawaii, he keeps an FJ cruiser there. Lots of cars get stolen in Honolulu so he wanted a way to disconnect the battery. I went to west marine and got one of these
m-Series Mini Single Circuit ON/OFF Battery Switch with Removable Knob | West Marine
And installed it on the negative side, in a hidden location. The knob is removable so you can turn it off and take the knob with you. It also keeps his battery from draining when he isn’t there for long periods of time.
 
It's kinda aggravating on a street car that's driven a lot. I thought about it on Vixen and still may put a main kill switch on it, but I'll leave the radio memory attached to power, as resetting the radio every time I drive it would be stupid.
 
dadsbee said:
Haven't tightened the bolt on a negative cable in over 40 years. Terminal in place, then push and twist. Never an issue and always removed as soon as the cars are parked in the garage and easy to quickly remove in an emergency.
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I’ve been doing the exact same for almost 30 years too.
 
I’ve already got a kill switch (tied into starter motor circuit even if the thieves bring another battery thinking I’ve bypassed the battery) hidden in Scamp so the battery switch would just be for safety over the winter.

Ive had issues with poor connections between the post and terminal on my battery so I’m a little shy to be popping the terminal off.
 
Mine...
Walmart I believe
H22A4 said:
I’ve been thinking of a battery disconnect for my Scamp, primarily for when I rarely drive it during the winter.

What battery disconnects are you using? When I read reviews on some, half of them indicated they were crap (ie: broke or didn’t fit). Post up yours if yours so I can get a good one!
Click to expand...

20230620_215838.jpg


20230620_215932.jpg
 
I've got the nhra mandated shutoff at the back of the car, that anybody can see, and another concealed inside the car.
Unless both are on, it's not going anywhere.
 
SlantedMark4 said:
This might sound weird and I might get laught on, but I'm just wondering if I'm the only one with this "fear".
I always disconnect the battery (I have installed a battery dosconnect switch) when I park my '74, even on meets. I'm worried about a fire caused by the battery. I mean, if I turn off the car and the battery is connected, there's still some load on the wires, right? I just think due to the age of the wiring, isn't it possible to cause a fire when the battery isn't disconnected?
I have to say, I've had two incidents with the wiring that almost ended in a fire (broken original amp. meter that ended pretty bad and a blown fuse)
Click to expand...
I have new wiring in my car and did everything I could to make sure it was done right but yes I have a battery shut off switch and when I park it I disconnect the battery every time.
More of an anti theft device but also just encase something goes wrong.
 
I have a shut off on all my old stuff.
 
Bennoel 10 said:
I don't think that is 100% true
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Do you unplug all of your lamps and blenders etc from your home when you leave?

A switched cir that is attached to the battery has 0 amps flowing while the switch is off.

It's the same as the battery disconnect switch
 
RustyRatRod said:
The ammeter is always hot
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But just like in your house (all the wires in your house are hot all the time)

Unless current is flowing (ie a load is applied and a complete circuit is made) it poses little to no hazard

If the wiring is in decent shape there is little to no hazard.

For me... I leave the battery attached 24 /7
 
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