can you jump start a car with a corroded battery

[Nicola]

Yes, you can jump-start a car with a corroded battery, but it requires extra caution. The white, blue, or greenish crusty substance on the battery terminals is corrosion, which acts as an insulator and prevents a good electrical connection. Your primary goal is to establish a clean connection between the jumper cables and the battery terminals for the jump-start to work effectively and safely.

Before connecting the jumper cables, the corrosion must be cleaned off. For your safety, always wear gloves and eye protection. A simple and effective cleaning method involves using a mixture of baking soda and water. A tablespoon of baking soda in a cup of water creates a mild alkaline solution that neutralizes the acidic corrosion. Apply this with an old toothbrush or a stiff wire brush to scrub the terminals until the metal is clean and shiny. If the corrosion is extensive, you might need to use a dedicated battery terminal cleaner tool.

Once the terminals are clean, you can proceed with the standard jump-start procedure. Even with clean terminals, a severely corroded battery might be too damaged to hold a charge. The corrosion can indicate a battery that is old, leaking, or nearing the end of its life. A successful jump-start may only be a temporary fix. After the car is running, it's crucial to have the battery and charging system tested by a professional at an auto parts store or a repair shop to determine if a replacement is necessary.

Corrosion Level	Resistance to Current Flow	Likelihood of Successful Jump-start	Recommended Action
Light (Minor white powder)	Low	High	Clean terminals, jump-start, monitor battery health.
Moderate (Visible buildup)	Medium	Moderate	Thorough cleaning required; battery may be weakened.
Severe (Thick, crusty layers)	Very High	Low	High risk of damage; professional assistance recommended.
Corrosion with Casing Damage	N/A	Very Low	Do not jump-start; replace battery immediately.

[Andrew]

You can try, but you gotta clean those terminals first. That crusty stuff blocks the juice. I’d put on some gloves, mix a little baking soda with water, and scrub it off with an old brush. If you just clip the cables onto the corrosion, you'll probably get a bunch of sparks and nothing else. Once you see clean metal, then hook up the jumper cables like normal. But honestly, if the battery looks that bad, it's probably on its last legs anyway.

[VonRonan]

I'm very cautious about this. Corrosion indicates a potential battery failure and can be a safety hazard. My first step would always be to put on safety glasses and gloves. Then, I would carefully clean the terminals to establish a proper connection. If the corrosion is extreme or the battery casing is cracked or bulging, I would not attempt a jump-start. In that scenario, the safest course of action is to call for a tow truck or roadside assistance instead of risking damage to the vehicle's electrical system.

[VonElias]

The real question isn't just if it will start, but what happens next. Corrosion is often a symptom of a deeper issue, like a battery that can't hold a charge. You might clean the terminals, get a successful jump, and drive away, only to have the car die again an hour later. The jump-start gets you going, but it doesn't fix the underlying problem. Plan on driving directly to a repair shop or parts store to have the battery and alternator tested. Consider the jump-start a temporary solution.