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Looking for Tips on how to Jump Start from Spare Battery (for a couple weeks)

Hi there… For those who might want to see the basic question - I’m looking for advice on how to maintain a spare battery for jump-starting my car for a couple weeks. Seems I’m guna have to jump it almost every time I start it. Mechanics here are closed til April so I have to get myself through till then. I bought a spare battery for this today and I know I can’t use it over and over without recharging… figure I’ll have to keep it connected to my car battery after jumping it, to recharge. My question is - do I do this every time I use it? How many minutes should I keep it connected? How long can the battery sit unused before losing charge? And do you have any other safety or maintenance tips for this method of starting a car? If it matters, I’m here in Malaysia where our batteries are still the old kind with four screws you open to add battery water. I drive a 1999 Proton Saga Iswara.

Found some notes on this on Quora… that it might be dangerous to carry on the car, especially if it gets toppled over, acid can leak out. Maybe i should just keep the battery at my house in case i need a jump when I’m alone, then depend on other people if I’m in town.

Okay, if background helps - I started having odd behavior from the car starting a couple weeks ago… delayed response for electrics to show life after I turn the key to accessories, clock would reset to 1:00 when I tried to start it, sometimes it would just clickclickclick. Took it to the mechanic and they jiggled some wires and ran some tests, said the battery’s fine, didn’t charge a dime - love those guys - said to come back if it kept acting up, and I’ve been meaning to go back cus it was still acting up, but I’ve been so busy and here I am… Just last night it did more than act up, it refused to start. We had to pop the clutch… reminded me of college. Anyway so go figure country’s on lockdown starting today for Covid, and for some crazy reason they think mechanics are a non-essential service. So I went by a mechanic and just called through the gate (it’s their house, most mechanics here have their garage at their house) and I bought a spare battery to jump it for now, since that’s what my mechanic always does. I asked them a lot of questions but my Malay just isn’t that good, so I thought I’d look online for tips… but there’s surprisingly little advice about this online. In a couple weeks the mechanic will open again and we can find the underlying problem. For now I just need this spare battery to get me through the next couple weeks. Any advice will be appreciated. Stay safe everyone.

Several if-s in your case:
If you have a fully automatic charger-one that goes to a maintenance level after full charge is reached.
If you can charge the battery outside of your house.
Then I think you might be safe leaving it on the charger while you are away, but still somewhat risky.
To take the battery with you see if you can get a battery case (plastic box) that is used in boat, then build wood bracing to secure it in your car. You definitely do NOT want a battery to tip over in a car.
I wish you luck, this virus is affecting the way of life for all of us.

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Thank you for the advice. I don’t have a battery charger. I figure i can recharge it by just keeping it connected to the battery in my running for some amount of time. Is that right?

If your charging system in your car is good—yes. But might put undo strain on the charging system.
I am very curious what your mechanic will diagnose as the underlying problem, one they are open for business again.

In the meantime, remove the battery cables and clean the connection. I suspect that or where the cables connect to your car are corroded causing the problems.

Thank you! How many minutes do you suggest charging the spare after jumping the car, supposing i rev the engine?

That I can not tell you, I really don’t know.

If the battery in your car tested good, then why are you having to jump start it ?

I’m thinking your alternator is shot and and won’t charge either battery.
or you have loose and dirty connections at the battery.

Thank you for the advice… as the mechanic just cleaned and fixed up the cables, I’m assuming the alternator is shot and so im not trying to charge the spare battery. Does anyone perhaps have an idea of how many times i can jump the car with a spare battery without charging it? There’s about ten more days minimum till the mechanic opens, and i have to jump it once a day when there’s no one to help push start it. I could perhaps stop by the place where i bought it and ask them to charge it. I’ve used it three times already.

if your alternator is shot and you jumped the car, it would not keep running, as eventually it would discharge what is left in your main battery and car would die

I would assume your alternator is alive and all your trouble is a bad main battery

do you have any skill with a wrench to swap the batteries yourself?

Ah thank you… I didn’t realize that. Explains why it’s not showing the other symptoms of a bad alternator. I could switch out the battery myself. It’s a new-ish battery, just a couple months old, and the mechanic said it’s still strong. So it might be cables somewhere. I could get my hands on a wrench and try my hand at it, though I’ve never switched a battery on my own before. Notably, it’s been starting on it’s own on occasion… especially after a long period of driving and only being parked for a few minutes. Seems like somethings draining it when it sits, but there’s nothing on.

Does this car have a remote starter system? If so, that may be malfunctioning and causing the ghost starting and battery drain.

Or is the engine not actually starting, but perhaps the cooling fan is coming on (especially after a long drive)?

I believe the OP means it will sometimes start without being jumped.

Ah yes. I see. :eyes: :crazy_face: The wording was a bit ambiguous. I had just read the other old thread about the car starting by itself.

If it starts well after a long drive, then it seems the battery is being well charged during that time, and after a fresh charge, it at least temporarily has the capacity to start.