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Porsche 993: How to Replace Battery

Whether by accident or by age, a bad battery is inevitable. This how-to will guide you through changing the battery yourself.

By Jared Hammond - March 20, 2015
Contributors: joeycannoli

This article applies to the Porsche 993 (1993-1998).

It's a fact that batteries go bad over time and will probably need to be replaced at least once over a car's lifetime, but it's hard to know when it needs to be replaced. There are a few signs such as partial leaking and corrosion that smells like rotten eggs. Outside of that, you can get your battery tested at an auto parts store or a garage. While a replacement battery isn't cheap, installing one is fairly simple and can be done on your own. The steps below will show you how.

Materials Needed

  • Replacement battery
  • Vent tube adapter if new battery doesn't come with one
  • Ratchet w/ 10 and 13mm sockets

Step 1 – Get access to the battery

Open the hood and remove the spare tire so it's out of the way. Then, twist the two tabs on the battery cover to release the clips and open the cover.

Figure 1. Spare tire and battery.

Pro Tip

Disconnecting the battery will cause all of your electronics to be reset. To avoid this, you can connect your OBDII port to either a jump start battery or another car.

Step 2 – Disconnect the terminals

Always disconnect the negative terminal first. If you touch metal to the positive terminal while it's still grounded, it could short your car's electronics.

Figure 2. Disconnect negative terminal first.

Step 3 – Remove old battery

Pull out the vent tube, undo the bolt on the lower clamp and remove the clamp, and then pull on the handles and slide the battery out of the tray.

Figure 3. Vent tube connects to the center of the battery.

Step 4 – Install new battery

Install your new battery the same way you removed the old one by sliding it into the tray. If you're using a non-OEM battery, be aware that it probably won't fit the same way the old battery did, especially if you're using a smaller, lightweight battery. You may have to leave off the clamp. The battery should sit snug with the spare tire next to it, but if for some reason you don't have the spare tire, you might want to get some kind of replacement clamp or brace.

Figure 4. Alternative clamp.

Step 5 – Finishing up

After the battery is sitting secure in the tray, reattach the vent tube by hooking it to a vent tube adapter. Then, reconnect the terminals, connecting the positive terminal first and then the negative. After that, put the spare tire back under the hood, and you're done.

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