Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

How quick does a battery drain???

  • 23-03-2011 5:18pm
    #1
    YourName
    Registered Users, Registered Users 2 Posts: 728 ✭✭✭


    Hope this is the right forum, thought you guys would know more about this than the people over in motors as you are modding the electrics a lot.

    I am going on a two week camping trip and we will have a plug in cooler plugged into the cigarette lighter while we are away. It is a socket that has power all the time, even when the ignition is off. Obviously we will be driving during the day but we would like to have this plugged in over night and that if at all possible, how quick do you think this would drain the battery???

    Would it be a good idea to hook up a voltmeter to the battery wired into the car to keep and eye on it in case it goes down to far that the car won't start???


Comments

  • #2
    Graham_B18C
    Registered Users, Registered Users 2 Posts: 8,620 ✭✭✭Graham_B18C


    Depends on the load of the cooler. I personally wouldn't risk leaving it overnight. The battery in my car isnt in the best health, if I was to leave my lights on for a few hours the car won't start


  • #3
    punto gt turbo3
    Closed Accounts Posts: 33 ✭punto gt turbo3


    pick up a new battery as a back up as more than likely it will flatten the battery. Also if the alternator is constantly used to charge a discharged battery then it to can give problems but this is unlikely in a modern car.


  • #4
    dougie-lampkin
    Closed Accounts Posts: 677 ✭✭✭dougie-lampkin


    Look up the current rating for the cooler, should be on it somewhere, or else on the manual. On your battery there should be an Ah rating, as in how many hours it can pump out 1 Amp for. This will give you an idea of how "big" your battery is for what you need. You can't run down the battery more than about 50%, or there just won't be enough juice to crank the motor. You need a decent safety margin on these things.

    It's also very bad to discharge and recharge a car battery even if it has enough juice to withstand running the cooler all night. It'll kill your battery long term. For this job you need a deep-cycle battery, they're built to be constantly discharged and recharged. You could connect this using a ready-made circuit into your charging system, so that the second battery is recharged by the alternator, without interfering with your main car battery.

    Also, a voltmeter won't tell you much. A battery with a pd of 12V still mightn't be able to crank a car. Two of these in series will add up to 12V, but won't make your starter cough :pac:


Advertisement