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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50
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6answers
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 ...
34
votes
3answers
33k 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 ...
28
votes
3answers
11k 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 ...
23
votes
6answers
87k views

Pros/cons of higher capacity car battery?

I'm shopping for a new car battery for 1998 Subaru Outback (2.5l). For the physical dimensions the battery has to match, I see some variance in capacity (Ah) rating, and in price too, of course. The ...
21
votes
4answers
3k 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 ...
21
votes
6answers
24k views

Is Start & Stop technology good or bad for my car? (Alfa MiTO)

I was recently in the lucky position to obtain an (almost brand new) Alfa Romeo MiTo, Progression. Like many new cars coming out these days, it has "Start & Stop" technology that turns the engine ...
17
votes
9answers
47k 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 While they have all been replaced by warranties, it'd be nice to get the problem solved permanently.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 ...
16
votes
5answers
11k 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 ...
16
votes
5answers
62k views

What causes battery terminal corrosion?

I put a new battery in my car about 8 months ago. After a problem starting a couple days ago, I found that there was massive corrosion under the battery terminals, so I cleaned them out and ...
14
votes
5answers
73k 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 ...
13
votes
4answers
203 views

Can a weak battery destroy an alternator?

I've heard a story that a weak vehicle battery can destroy an alternator or cause an alternator to fail early. Is this true, or is it largely fiction?
13
votes
1answer
284 views

Replace car batteries with capacitors?

I recently watched this video on YouTube which basically shows the guy replacing a larger capacitors with some smaller capacitors which he had bought. The larger capacitors were actually in place of a ...
12
votes
3answers
2k views

Why is gas around a car battery only at risk of ignition from jumper cables?

As pointed out in Jump starting a dead battery: Connect black wire to negative pole of battery or grounded metal?, you connect the black jumper cable to the dead car's chassis to avoid sparks made ...
12
votes
5answers
4k views

Should negative trickle charger clips be attached to the battery negative terminal, or ground?

I'm trickle-charging a car using direct connections to the battery. I thought this couldn't be simpler: ventilate, unhook the battery, connect the positive first, then the negative, then turn on the ...
12
votes
2answers
1k views

What can we reliably tell from an in-vehicle battery voltage display?

The Red Cross division I am with recently purchased a new ambulance. It comes with a touchscreen display in the cockpit where we can control lights, sirens, check the temperature in the back, control ...
11
votes
2answers
6k views

Why might I experience a power falloff after starting my car with the AC On?

I have a 2000 Chrysler Neon which generally runs well. I have noticed that if I start the vehicle, turn the AC on and reverse out of the driveway, the engine seems to struggle/sounds like it is going ...
11
votes
2answers
2k views

Remote Key Fob working only inside the car (close to reciever)

I am struggling to get my Peugeot 308 2-Button Remote Key back to work. I noticed first issues when my Remote Key unlocked / locked the car after several attempts. Then one day it suddenly did not ...
10
votes
5answers
917 views

Can a car AC unit be run on just the car battery?

This might be a silly question but I was wondering if a car AC unit be run off entirely on battery or alternator? As this could help in Preventing power loss during important times such as ...
10
votes
3answers
505 views

How to upgrade a motorcycle battery to a bigger AH battery?

My motorcycle (honda CBF150) came with a 12V 3AH battery. I want to change the stock 35w headlight to a higher power one and connect them directly to the battery (the stock ones are not, and they ...
10
votes
4answers
10k 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 ...
10
votes
1answer
64 views

Is there any advantage to keeping the battery “topped up”?

I got an engine/cabin heater installed into my car right before winter, which was great for driving comfort this winter. One of its "side-effect" features is that it charges and keeps your battery at ...
10
votes
2answers
154 views

Unknown part fell out of my motorcycle

So I was taking the battery out of my bike (99 Honda Shadow 750 ACE) to ship it this past December, when two parts of the bike I'd never seen fell out from somewhere near the battery case. They sort ...
10
votes
3answers
15k views

Using a car with an inaccessible negative battery terminal to jump start

When trying to jump start my Volvo XC-60, I came across a very unexpected problem. I tried to use our 2nd vehicle, a 2010 Ford Escape, as the assisting car to jump start mine. But when I looked at ...
10
votes
1answer
215 views

Are there downsides to making an accessory socket always live, if accessories are removed when not in use?

In some cars, the power line from the battery to the accessory outlet (aka cigarette lighter socket) is always live. In others, it's off until ignition. It seems pretty much random which cars are ...
10
votes
2answers
1k views

Can I safely upgrade to an AGM battery?

AGM batteries are capable of being charged at a faster rate, and may draw additional amperage from the alternator if it is not regulated. Many cars that come with AGM batteries have special charge ...
10
votes
1answer
91 views

Do any car batteries come dry with the electrolyte in a seperate container?

Small batteries for Motorcycles and Lawn Tractors are typically sold with the electrolyte in a separate bottle and must be added to the battery at home before installing it. I've never seen a "dry" ...
9
votes
4answers
71k views

What could cause my Honda Civic to not start? And how can I address the issue?

I need help trouble shooting my honda civic. It will not start. I was driving it earlier today and I went to drive it again when it would not start. I'm glad I was at home when it decided to quit. ...
9
votes
2answers
324 views

Non-functional gas pedal, engine stalling, dead battery: broken alternator?

I have a 2005 Nissan Sentra. The following happened twice within a few days: I stopped at a red light. When the light turned green, pressing the gas pedal had no effect at all. However, the car ...
9
votes
4answers
8k 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 ...
8
votes
3answers
1k views

Is charging my engine battery like this bad?

I left a 2001 V6 Honda Accord unrun for ~4 months (I don't have a license). Naturally, the battery is dead. I have heard that letting the alternator charge the battery from empty like this puts ...
8
votes
5answers
27k views

How do I know if my car battery is dead?

By mistake, I left the headlights on overnight for my Honda Civic 2008. 24 hours later when I tried to start it, the car would not start and nothing would come on including the internal lights and the ...
8
votes
2answers
3k views

Why should I connect the red/positive terminal first when jump starting?

So, it's fairly popular consensus online that it's red/positive clips to the positive/red posts, then the black/negative clip to the frame One site mentions sparks, but you'll still get a spark when ...
8
votes
6answers
24k views

2004 Ford Escape battery light comes on intermittently - what likely cause(s) are there?

I have a 2004 Ford Escape Limited on which the battery light has been coming on randomly for varying amounts of time while the vehicle is in active operation. I have checked the battery cables and ...
8
votes
2answers
126 views

Old starter clicked, wont turn over engine. New starter wont even click - no noise at all

My old starter would click, but not turn the engine over. I got a brand new starter and installed it. The only two wires connected to the starter are completely different and can only be fit in the ...
8
votes
1answer
246 views

Does this crack in a battery terminal post indicate that the battery should be replaced?

Mechanics at the local garage have insisted it's "no problem yet", but people here in Sierra Leone have different standards to me when it comes to car safety... This is a pic of the positive terminal ...
8
votes
4answers
5k views

Can I jumpstart a non-hybrid car from a hybrid or full electric car?

This morning I had starter battery troubles with my 2001 VW Eurovan. As it happened, my father-in-law arrived just at the right time in his fancy new Toyota Camry hybrid. So we opened the hoods, dug ...
8
votes
1answer
119 views

Disconnected wires near battery in BMW e46

I noticed a disconnected wire dangling next to the battery in the trunk of my 2005 BMW 330ci. It was actually a red and blue wire that veered off from the thick red one in the middle of the image. ...
7
votes
8answers
4k views

Why use a car battery charger?

What's the need for car battery chargers that I often see on display in auto parts shops? I mean a battery is sold charged (and if it discharges too much it just dies and can't be restored) and every ...
7
votes
4answers
41k views

How to diagnose a starter motor that does not work

My e46 M3 would not start when I got to the parking garage after work. When I first turned the key, I heard a sound like grinding gears, but I was so startled that I immediately stopped trying to ...
7
votes
4answers
930 views

Corrosion on battery, won't start, making clicking noise, won't charge

I'm trying to charge the battery on my 2002 Celica. Here is some background: Battery is a bit old, around 3 years or so. Corrosion has been building on the battery to the point that it almost ...
7
votes
4answers
6k views

Does turning off the radio and other electronics in a car before shutting off the engine prevent battery drain?

My father in law tells me if I leave the radio on in my car when I shut off the engine this will cause a bit of battery drain when I start the car. He says this will actually reduce the life of my ...
7
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 ...
7
votes
3answers
227 views

Portable jumpstart kits: why aren't regular car batteries this small?

I was looking at the details of this jumpstart product: It claims to be 2 lbs and 14.2 x 12 x 3.5 inches, which I think is for the outer black canvas case, so I would guess the actual device is ...
7
votes
3answers
582 views

Why do attempts to charge a flat car battery with an electronic battery pack give results as if there's a short circuit?

I'm not having a good weekend - car wouldn't start, even when jump started using a conveniently placed 12v generator battery (almost identical to this question, I suspect dodgy cabling to the ...
7
votes
2answers
434 views

12V Battery change

4 weeks ago I changed a 12V battery on my Toyota Prius auto. But after being in for two weeks the battery was discharged again. I tried to recharge it, but it did not work - the charger does not start ...
7
votes
1answer
397 views

Why the different the colors of terminal corrosion on the battery?

I have a 2001 Ford Windstar. When I went to clean the battery terminals: the one with the RED cover over it was a bright blue color; the other had normal white corrosion. I do not know why the this ...
7
votes
6answers
60k views

How many amps should my car pull while it is turned off?

I've recently started having a bit of trouble with my car. I typically drive my car to and from work each day. A couple weeks ago I went on vacation and when I returned, my car battery was as dead ...
7
votes
2answers
8k views

How do you remove or even get to the car battery on a 2012 Honda Odyssey?

Summary How do you get to the battery on a 2012 Honda Odyssey, given that it is blocked by some type of intake tube**? **Edit: this used to say exhaust but I changed it to intake tube, given ...
7
votes
7answers
59k views

RPM and duration to recharge a battery?

My car had been sitting for a while without being driven. The battery now has a weak charge but it can get the engine started (barely). I would like to charge the battery by running the engine, but ...
7
votes
2answers
6k views

Can an engine stop from a bad battery?

The car is a 2005 Toyota Corolla CE. Its engine is the 1ZZ-FE, a 1.8L straight four that runs on gas, not diesel. The alternator is stock, and tests out just fine on the multimeter in both voltage ...