A flat car battery (petrol)

amandstu

My battery went flat because the ignition was left in and the air conditioning was on for a good few hours.

It is not completely flat.

Can I leave the battery in a warm place for an hour or so and try again ?

I can always get a call out from Aviva in the morning but would prefer to fix it myself if I can.

It is just a petrol car (Toyota auris) and I know batteries can come back in a day or so unattended.

Can I give it a boost by giving it a gentle warm in a warming oven(about 60 degrees or so ) or is that risky?

User1998

Do not put the battery in the oven!!

You need to jump start it or charge the battery. The battery won’t just come back to life by keeping it warm

McCrack

Keep in for no more than 20 min and sprinkle of mild herbs like some coriander for a bit of "je ne sais quoi"

amandstu

Thanks .I did a quick google before reading your replies.

I have taken it out of the warming oven (it was just in for 10 minutes) as I could see any thing above a summer's day's heat could damage it

Maybe if I can warm it to around body heat for a while that won't damage it.

I know batteries do recover just with time as this has happened to me when the car conked out and I returned the next day to find to my surprise that it started on it's own.

I thought maybe a bit of warmth might accelerate the process .

I have done it before in very cold weather and was successful but this is not frosty and the battery ran down by being left on.

antodeco

Surely this can't be serious? If you have the know how of how to disconnect and remove a battery properly, you'd clearly know not to put it in the oven.

amandstu

https://www.boards.ie/discussion/comment/121373644#Comment_121373644

It is a warming oven.I just use it for keeping plates warm .Not for cooking.

Temperature varies.Might be 50 or 60 .

But I can see that is still too high and so have taken it out.

We can call out someone in the morning but I am so annoyed to have done this and it is not the first or second time.

zg3409

You can often get a jump start from a friend or neighbour or even ring a local taxi company and they are typically quick with jump leads. Some cars can be push started if battery is not fully dead.

elperello

If you have access to a second car a set of jump leads will get you going.

Dr_Colossus

Aircon is pretty heavy on the battery so it's bound to be pretty flat if left running for hours. Probably sufficient charge remaining to show dash lights and even dipped beams but not enough to crank the engine.

Have you jump leads or any neighbour with some? Just needs a jump start and a decent drive to recharge the battery.

My battery after just over 6 1/2 years is dieing (got 10 years from the original) as doesn't really hold a charge (voltage drops) and is slow to start. Car failed to start a couple of times recently with just the radio running for 30mins or so. Will have to buy a new one this week.

amandstu

https://www.boards.ie/discussion/comment/121373677#Comment_121373677

It is a very cool oven of a range (always on ) and I have done this in the past in freezing weather when the battery would not start in the morning.

Maybe not in the warming oven but at the back of the range.

I took it out this time pretty quick when I realized it was just too hot for it

I have it at the back of the range and may give it go in an hour or so if I can warm it very gently to about 30 degrees (if that will help)

amandstu

https://www.boards.ie/discussion/comment/121373690#Comment_121373690

I might actually.I have the jump leads in the car and our neighbour's car might be out of the garage by now (we have been ferrying her around the last day or so)

Atlantic Dawn

I've had some luck before with leaving it a few hours and trying again wherebye I make sure before that attempt that every single battery drain item on the car was disabled like fan, heater, auto lights etc were all off, if lucky you might get a single turnover or 2 and it might or might not work. Last throw of the dice really.

amandstu

https://www.boards.ie/discussion/comment/121373708#Comment_121373708

Thanks.If it doesn't work Aviva will come out for free.But they may lose patience with us as this is the third time!!

Maybe they will charge us ;-(

Lewis_Benson

I don't think I have ever read anything so stupid.....car battery in the oven?

Jesus

wandererz

Craziest thing I've heard of this year.

But...just go ahead and put it back in the oven until the explosion.

If you're not there when it happens then you can collect the insurance.

amandstu

What happens to car batteries when the temperature goes above 40 on a typical summer's day in some countries?

Does it explode or does it just degrade the battery life

I have taken it out of the oven but I don't think the temperature in it was hotter than a very hot summer's day.

This is a range I was talking about.

There are 4 ovens.One is high temperature cooking. The next is lower temperature cooking.

The 3rd is a simmering oven (so around 100 degrees)

The 4th ,which I was actually talking about is a plate warming oven and so the temperature would be that of warm ,but handleable plates.

I was asking whether that would damage the battery .

The consensus was "don't do it" and I am not .

But if I had to give an inexpert opinion I don't think a petrol car battery would explode

It is one of those things that you "don't try at home" but might well be OK if you know what you are doing (which I didn't)

I often put AAA batteries in the simmering oven for a while when they get flat and it nearly always revives them for a good while.

I will put the battery back in the car in am hour or so and see if the downtime has given it a boost

Otherwise we will probably call out the garage in the morning.

Mellor

https://www.boards.ie/discussion/comment/121373899#Comment_121373899

Regardless of whether it would have exploded or not. Not did you think a warm oven would electrically recharge a battery?

Ubbquittious

Do people not have anything to charge batteries with or even a few bits of old wire in the shed for jumping off an other battery? Or try push start

Also I have never seen air conditioning run off the battery in a normal non-EV car. Not saying this system doesn't exist

Even if you tied the wires from the power supply off an old eircom router to your battery for the night you might get enough charge in it to start in the morning. Heating it up in the oven sounds like a hair-brained scheme

amandstu

https://www.boards.ie/discussion/comment/121373901#Comment_121373901

I think it might be helpful (not to recharge the battery ,just to kickstart it)

Heat normally accelerates chemical reactions and ,as I said it works unfailingly with the batteries in the remote control for example

But as someone said ,just letting the battery lie will have the same effect.

amandstu

https://www.boards.ie/discussion/comment/121373902#Comment_121373902

I definitely head the swoosh of the car heater when I turned the ignition.

Something must have drained it and the lights weren't on and I didn't hear the radio.(the dash lights were on)

I did have an old fritzbox router but I took it to the recycling a couple of weeks back(sounds too technical for me anyhow

Ezeoul

I can't believe you put a car battery in an oven.

Read this thread and treat yourself to a battery booster.

https://www.boards.ie/discussion/2058320274/best-jump-leads#latest

Ubbquittious

https://www.boards.ie/discussion/comment/121373920#Comment_121373920

That would do it if you still have the power supply.

Take off the connector and strip off about 10cm of wire to wrap around each terminal. The positive wire is the one going to the hole of the plug that goes into the router

amandstu

https://www.boards.ie/discussion/comment/121373934#Comment_121373934

Thanks I got rid of that router a couple of weeks back and I think the power supply with it.

This is pretty academic but I have found the power supply that worked an old Triax freesat receiver.

I wonder whether that would work?

There is just the one round connector at the end of the wire.I don't know how I could tell which was the positive wire...

In any case I won't do that.I put the battery back half an hour ago but it didn't even turn the engine (the dash lights did come on)

In the morning we will call out Aviva Breakdown and just hope they don't charge us for being so stupid .

ozmo

I think they are supposed to charge you if it’s in the driveway. Ie. Not a breakdown. So fair play to them if they do it for free.

Battery in oven - or even overcharging in house is bad as they can vent off dangerous gas when hot:- hydrogen sulfide. This gas is colorless, poisonous, flammable, and has an odor similar to rotten eggs… Heat wasnt boiling hot- but still wouldn't be advised.

wandererz

How old is the battery?

If your battery has died a few times already then it is time to get a new one

Especially over the winter months it will be a saver.

Secondly, have a look during the black Friday sales for a Noco boost GB40 boost pack.

This will help you if you are out and abouts only to find upon return that your battery is dead - or even be a good citizen and help someone else.

Even cheaper is a charger, this will charge your battery overnight if it is dead and recondition the battery as well.

This is slow and works overnight and is best for home for yourself or your neighbours.

Something like this

8A Car Battery Charger,12V/24V Battery Charger with Temperature Compensation,Leisure Battery Charger,LCD Screen Smart Battery Charger with Maintainer/Pulse Repair for Car, Motorcycle,AGM. https://amzn.eu/d/hiuQzmm

amandstu

https://www.boards.ie/discussion/comment/121373946#Comment_121373946

Yes that is pretty cheap.I had one but it rusted away years ago.

The battery is only about 3 or4 years old but we have drained it a few times already by leaving the lights/radio on.

mikeecho

The safest way to to warm the battery, is to put in the bed next to you under the duvet, once it has warmed , you can then try and jump it.

amandstu

https://www.boards.ie/discussion/comment/121373960#Comment_121373960

Sweet dreams are made of these.Nighty nighty.

Spook_ie

https://www.lidl.ie/p/portable-jump-starter-with-power-bank/p10014164?pageId=10033836&tabCode=Current_Sales_Week

for when you do it again

Mellor

https://www.boards.ie/discussion/comment/121373914#Comment_121373914

You have it backwards.When the chemical reaction is complete, a battery is dead. You need to slow the chemical reaction, while the potential difference builds up. You need to put the batter in a fridge or or freezer (not colder than -12deg).

This the fail safe way to make 12v batteries last longer as a kid

amandstu

https://www.boards.ie/discussion/comment/121373943#Comment_121373943

They came out this morning and no mention of a charge.Said the battery was fine (ie no damage from being drained).

Was touting automatic cars as the way to go.