Replacing the battery

[ShropshireLad]

The battery on my 997 - has given up the ghost and a new Varta via BatteryMegaStore is on its way (better cold crank and very good price with a 5 Yr guarantee!).

Can someone just confirm that I can simply remove the old unit and put in the new, without a 'code saver'?

There are various pieces of advice on line - however, speaking to my local garage they don't think anything is required?

Their logic being is that if the battery in the car completely flat (which it is), when you then apply a charging unit or jump start the car. does the car "accept" this sudden jolt of 12v (which it does - without any resets) - "so swap out the old and fit new".

Can someone give advice please?

Thanks

 

[timbo1811]

There is plenty of advice on here if you do a search, basically simply swop, then reset windows, you may need to drive a little to clear any lights that do appear.

 

[6times7]

PSM failure came up on my dashboard after reconnecting the battery, which led to some googling!

It cleared after driving off.

 

[jl-c]

Reset windows and reset sunroof.
Hold window switch down for 5 seconds after it is fully down, repeat for fully up. Windows should be reset, check if one touch works if so they are done.
Motor for sunroof
The limit positions of the sunroof are deleted from the control unit when the battery is disconnected and connected.
- Switch on ignition.
- Press the rocker switch to open until the sunroof is completely open.
- Press the rocker switch to close until the sunroof is completely closed.
Touch the one-touch function and check if the sunroof is in the end position for "optimal noise level".
If not, then repeat the process.
-
The end positions of the sunroof are now stored in the control unit again.

Turn steering 20 degrees left then right, drive straight ahead for a few yards, that should reset the steering angle sensor, then go for a drive, everything should reset itself. Don't worry about any warnings or errors unless they do not clear after a 10-15 minute run.

 

[ShropshireLad]

Many thanks all - procedures and advice duly noted.

jl-c - from one Salopian to another 'thanks'!

 

[jonno_]

Don't forget key to position 1 before you disconnect.

 

[Pearson P Car]

Can anyone tell me what is the best battery for a gen 2 C2S?
Mine is showing 15.2v when running.

 

[deMort]

Can anyone tell me what is the best battery for a gen 2 C2S?
Mine is showing 15.2v when running.

Do you have any other reasons for replacing the battery other than the 15 volt charge listed ?

If not then i can say i often see the charge rate at this or sometimes higher .. it's good upto 16 volts and is merely the alternator charging a low charge battery or compensating for electrical loads along with charging the battery .

16 volt and higher and it's an alternator issue .

 

[ShropshireLad]

Just to conclude this thread.

I fitted a Varta F18 battery yesterday (I put the key in 'position 1) and cycled the electric front windows a couple of times, once the car started. The PSM was on when I started but this disappeared after - 20m - when driving off.

I will say this Varta battery has completely transformed the starting on my car - hot and cold - it actually spins over quickly now. It does have a much higher cold crank number and is 90ah.

It was also £85.86 delivered by the BatteryMegaStore (who were excellent!)

 

[Pearson P Car]

Can anyone tell me what is the best battery for a gen 2 C2S?
Mine is showing 15.2v when running.

Do you have any other reasons for replacing the battery other than the 15 volt charge listed ?

If not then i can say i often see the charge rate at this or sometimes higher .. it's good upto 16 volts and is merely the alternator charging a low charge battery or compensating for electrical loads along with charging the battery .

16 volt and higher and it's an alternator issue .

Not really, I do use a c-tech every few weeks. But the battery has never failed to start the car. Might see how it goes.

 

[Pearson P Car]

Just to conclude this thread.

I fitted a Varta F18 battery yesterday (I put the key in 'position 1) and cycled the electric front windows a couple of times, once the car started. The PSM was on when I started but this disappeared after - 20m - when driving off.

I will say this Varta battery has completely transformed the starting on my car - hot and cold - it actually spins over quickly now. It does have a much higher cold crank number and is 90ah.

It was also £85.86 delivered by the BatteryMegaStore (who were excellent!)

Thanks, will keep this in mind if I decide to change.

Another question, do you guys open the battery up when charging or do you just let the breather pipe do it's job?

 

[kurlykris]

4 years ago when I changed the battery in my 987.1 Boxster S ( it was just about holding a charge for 4 days or so , but above 10.5 Volts ) I lost the footwell lights, front and rear boot lights and Xenon headlight washers, this was rectified by our very own deMort at a 911uk meet at his workplace with a "handover reset" on his laptop :grin:

I changed it again this weekend and lost nothing as far as I can tell, I think it`s a bit of a lottery and software glitches, my battery had completely died this time, was at 2V and I`ve been playing with it trying to cojole it back into life, but it is having none of it :sad:

996.1 battery next weekend, lol, Porsches love to eat batteries when they are not being used, the 996 hasn`t even been started in 2020 since March

 

[deMort]

@ Pearson P Car

You Don't undo the cell caps , doing so would have any gas in the area of the battery .. a single spark from connecting a charger lead could in theory cause an explosion .

The reality is a trickle charger wont cause a battery to gas to any real extent and any that does occur will be vented out under the car and away from any possible sparks .

A fault with a battery cell and it might gas .. hence the above warning to be safe .

I've personally blown up a battery on charge many years ago and i've seen a mechanic that fitted one that was faulty .. been on an overnight charge and as he connected the battery leads it sparked and blew it up in his face ... the battery literally blows its top off .

rare as rocking horse S$!* these days but its always possible .




@ kurlykris

Young man it's been ages !!! .. all well and good i hope ?

I still have no idea why some cars do this and the vast majority don't .. i've had it happen to me so i know full well its not something that has been done wrong in the battery replacement .

Dam control units are the same as PC,s these days .. might not get a blue screen but things stop working .

handover is the same as turning it off then back on again .

I would guess at 1 in 50 do this .

It's the dam Vescu that is the issue .. an electrical control unit for the car .