Fitting a new battery

Hi. I am having numerous problems with Halfords refusing to fit a battery onto my 911 due to apparent concerns over the alarm and just being generally unable to do it... I am considering purchasing it myself and fitting the battery. I understand the ignition must be left on but since there are two ignition turns on the key, any advise concerning the self-fitting of the battery would be appreciated. I assume you remove negative terminals first when taking out the old battery, but is there a bleed tube i need to deal with given the replacement i want: Bosch Silver Car Battery HSB096, appears to be fully sealed. Thanks in advance, Steve

Steve, You need to provide a temporarily 12v supply during the battery swap. Use a jump lead set, a battery charger or a small 12v power supply to the leads until the change-over has been completed. Regards, Clive.

The fact that they wont do it should kinda tell you why not to use them in the first place.

I took my battery out to clean the tray as it had all leaves and crap on it. I just left the key at stage one (counter come up). I didnt use a backup and is was disconnected for a couple of hours. All that reset was the trip, average milage and average speed.

Yes - disconnect the negative first and connect it last - it eliminates the risk of shorting the positive to earth. Even the apparently sealed Bosch batteries have a hole in the top to connect the vent tube. Mine did anyway.

Thanks All, Does anyone know if the vent tube connector is identical on all batteries? ie. is it a simple attachment or do Bosch use a different vent design to say OE? Richard - did you find this issue and was attaching the vent tube on a Bosch better a simple task? Steve

I would recommend a Bosch S5 008 battery, direct fit, heavy duty, vent tube marries up perfectly and garaunteed I would also recommend keeping the key in the ignition during the swap, as it stops the alarm sounding when you reconnect, which sometimes happens... which due to the siren/horns position right next to the battery will make you jump out of your skin and possibly cause you to fall out with neighbours!

I've got the S5, and as Jon says, the tube connector plugs straight in the side.

leave the drivers window open , just in case ! 75pno

All, Thanks - just to make sure i get the right the correct Bosch spec battery for the original 911 venting pipe is: s5008 096 12v - HSB096 http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_734753_langId_-1_categoryId_165762 Thanks Steve

Same, did mine by puttin key at position 1, remove negative then positive and it won't trigger the alarm.

If you look at the photo on that page (hover mouse over photo to enlarge), you will see a small raised ring at the top left hand edge. That's where the tube connector plugs in.

If you're set on the Bosch 096 - 77Ah battery you could try here: http://www.boschbatteries.com/911-73/s5008-096-bosch-silver-plus-car-battery-12v-77ah-12-1-69.php

I think Bosch batteries have a plug that's there to plug the other side of the battery, e.g., if as you look at the battery the vent pipe is on the left, the plug goes in the exact opposite side of the battery (i.e. the battery is designed to allow a vent on either side with a plug in the other side). The plug is often in a bit of plastic that you break off (Hlafords own batteries have a red plug I think) - probably on the positive terminal - you remove it before connecting the terminal.

I fitted the Bosch Silver S5 battery HSB096 to my 40th Anniversary. £122.99 from Halfords or £84.65 if you have a trade card. Followed the guide on here, no problems

I might have to check my battery now, i think i just left the pipe hanging free. Edit; i found the pipe and plugged it in to the battery. What is the point of connecting it up,and how do i know if my battery is the original one?

The battery can produce hydrogen sulphide gas when charging and the vent tube allows the gas to vent away from the electrical connections in case there is a spark that ignites the gas. Very unlikely to happen but it can. The original battery should say Porsche and Moll on it. If you look near the terminals, there may be 4 numbers stamped near one of them which relates to the month and year.