A rechargeable device most often made of lead plates covered in an electrolyte and protected by a plastic shell which supplies consistent electrical energy to a motor vehicle. Often referred to as an SLI battery (starting, lighting, ignition). Powers starter motor, lights, and ignition systems of a ...

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16
votes
4answers
2k views

How do I test my car battery?

My car still starts fine but when I turn off the car (just the motor . . the key is still in and "on") I noticed the headlights dim to almost off. It's and older car and the headlights don't turn off ...
2
votes
3answers
555 views

how much water can be safely added to a battery?

My 2008 Jetta SE 2.5L has the battery as follows: ENERTEC EMC // 1J0 915 105 AD // 12V 61 Ah 330A DIN // 540A EN/SAE. It would appear that the battery can no longer hold the starting charge after an ...
38
votes
5answers
2k views

How to maintain a sometimes-used vehicle?

My daily commute changed from 9 miles to 9 feet when I started working remotely. That means I very rarely drive my car much. After a particularly hectic month, I didn't drive for about 4 weeks and ...
12
votes
6answers
32k views

Battery drains by itself when vehicle is parked (parasitic draw)

A 1998 Jeep Grand Cherokee has gone through 3 batteries in the last 3 months. While they have all been replaced by warranties, it'd be nice to get the problem solved permanently. I've tested the ...
8
votes
4answers
5k views

How to assess battery charge level and alternator performance?

What diagnostics can be done to to assess battery charge level? I'm interested both in one-off tests like can be done in car service and also continuous monitoring during normal use. Car panels ...
3
votes
4answers
8k views

Should I use coca cola or baking soda + water to clean my battery clamps?

The clamps that are attached to the car battery are corroded, I was told either of these liquids will work. Which one is better? Is there a how to guide on the exact steps I need to take? With my ...
22
votes
3answers
7k views

Jump starting a dead battery: Connect black wire to negative pole of battery or grounded metal?

Most of the advice I've seen for jump starting cars instructs to connect the black wire to a bare piece of metal on the car with the dead battery. However, I've always just hooked up both poles to the ...
12
votes
5answers
6k views

Adding a additional battery to car

I have purchased a brand new Toyota Innova. I need to install a a mac mini, 2 laptops and make this car a mobile office. I need to know if I can install another car battery in parallel, and will ...
25
votes
3answers
24k views

Is there a way to put Prius with dead battery into neutral?

I own a 2010 Prius. It has a dead battery, front facing forward in my garage. I do not have long enough jumper cables. I’ve searched the Internet. Did Toyota really create a car that cannot be put ...
4
votes
2answers
38k views

Car Battery won't charge after sitting for a Year

I have a main starter battery and a leisure batter in my van. They have been left unused for around a year with my van off the road. I am now trying to get it up and running however I am unable to ...
6
votes
3answers
2k views

How should I prevent my battery going flat when I leave my car alone for a month?

I will be leaving my Focus alone for around a month in (scottish) winter weather. Ordinarily I would make sure to take the vehicle out at least once a week to prevent the battery going flat in the ...
3
votes
4answers
19k views

What precautions are needed when charging a car battery in an apartment?

Suppose a car owner lives in an apartment building and parks his car nearby. He wants to detach the battery, bring it home and charge it with a mains-powered charger indoors. How to properly handle ...
11
votes
4answers
48k views

Is it possible to harm your car by giving someone a boost?

This post explains why it's a potential hazard to clip to the negative post on the dead battery when giving a boost. But I've also been told that I could damage the electronics in my own car if I give ...
7
votes
3answers
7k views

How do I apply dielectric grease to my battery?

I recently had a new battery installed in my 2006 Subaru Forester. The shop did not use any dielectric grease, just connected the leads to the terminal and that's it. What is the preferred method of ...
4
votes
2answers
149 views

When Jumping a Battery Why Red FIrst

So, it's fairly popular consensus online that it's red clips to red posts, then black clips to frames, but why red first? One site mentions sparks, but you'll still get a spark when connecting black ...
4
votes
2answers
124 views

how do i know if my lead-acid battery has been resurrected?

The OEM battery in my 2008 Jetta SE 2.5L has been nearly fully discharged one month back (had insufficient surface charge after a prolonged use without the engine running, but leaving it idle for 20 ...
3
votes
2answers
847 views

would a sulfated discharged 12V battery charge at 12.5V?

I got a Stanley FATMAX RE-CHAGEiT 8AMP Automatic Battery Charger & Maintainer from Walmart for 29,97 USD, which appears to have three states of charging the battery -- detecting the voltage, rapid ...
3
votes
2answers
139 views

Should i check quantity of battery liquid?

The battery of my Nissan Tiida is similar to the ones in the pictures below. Should I check if there is enough liquid inside? and in case it needs, should I add distilled water?
3
votes
1answer
196 views

89 jeep cherokee will run but when i turn it off and try to restart it the battery is dead

The battery is still good and the motor will keep running when you disconnect a terminal. Can my alternator be bad? If not I'm also thinking a dead short? What is the best way to find out?
2
votes
0answers
31 views

Negative surface charge?

At about 20°C, there has been a situation that the OEM battery in my '08 Jetta was not capable of starting the car at all (virtually no movement of the starter at all), after being used for at ...
2
votes
1answer
154 views

How do I add an auxiliary battery to a van?

I have a 2500 Savanna (GMC, 2001, extended), with an entertainment system. The stock battery is fairly small, and I don't want to run the engine or drain the engine battery when playing videos for ...
2
votes
1answer
338 views

Power vampire in car. Where do I start looking?

I have been to the car store four times and each time they tell me that the battery is good. A few of the cold-cranking amps (maybe at 50 or so, I don't remember the exact amount) are gone otherwise ...
0
votes
1answer
199 views

when trying to start my pajero it just clicks and wont fire up

pajero wouldnt start and just clicks had aa out and they said it was the alternator but tried car over weekend and it started first time. tried this morning and just click had to have a jump start to ...