connecting a charger to a 981 boxster

[rich mich]

I have been reading up on various sites on the net, how to connect a charger to a 981 boxster,and have found loads of info etc,using my car I thought I would look into it in more detail,what I saw on net and what a found out using my car,i am a sparky by trade,25 years working on dyno test cells,and car electrics .on the 981 boxster I found that after locking doors with key fob all power sockets are switched off after 30 mins,(to test this I used a power adaptor 12v ,3 way socket with a usb output and a 12v phone charger adaptor X2) after 30 minutes the sockets powered down when these were connected.looking on sites on the net it said you had to connect a charger to the + terminal on the battery and -ive body work of car(not -ive on battery as this will damage battery monitoring system on car ,Porsche sell a lead for this £20) . what I read on the net also was that

The vehicle's 12V sockets are deactivated if no charge is
applied for 30 minutes to protect the vehicle battery.
• Turn vehicle ignition on and off once before charging if the
ignition has been turned off for more than 30 minutes.
• Switch on the vehicle ignition once after the charger has
been disconnected for more than 30 minutes, e.g. through
a power cut.

what I found was that when I connected a charger to a power socket and powered up with in 30 minutes ,that socket would remain live as long as the power from charger was connected and if the charger lost power the car would switch the socket off in 30 minutes as it states above, (for some reason my smart charger was switching off after 30 minutes(lidl charger) ,my Porsche charger would not switch off after 30 minutes so I am using this now) I have now built my own charger using a 12volt, 0.8 amp psu and a solar panel controller module, and it works fine. reading on the net I also found out that if you fit a new battery to the 981,you have to tell the car a new battery has been fitted.(bmw have done this for over 10 years)

so what I have found is you can connect a charger to a power socket in a 981 boxster as long as it done within 30 minutes of locking doors,and if you leave a 12v adaptor in a power socket in the car it will shut down after 30 minutes,and when you open the doors with key fob it will repower back up.

added: the 981 boxster and cayman use a agm battery that has to be charged at a higher voltage 14.4v that's why Porsche sell 2 types of battery chargers,i have found out you can use the snowflake(winter) settings on other smartchargers ctek and others

 

[JATKN6POT]

My Lidl charger did/does the same thing with mine........... very frustrating. There must be a way to overcome this issue I will need to investigate further.

 

[JATKN6POT]

Check this link out. 8 pages on the same topic.
Problematic!
http://rennlist.com/forum...ery-via-lighter-8.html

 

[terry993]

Anyone know why you shouldn't connect the negative charging lead to the battery?

 

[rich mich]

I think the lidl charger detects the car is shuting down the socket ,and then shuts off ,goes into standby mode.i think the Porsche charger(ctek) when the car shuts down will auto reset so it will remain charging,(the solar controller module i use ,just supplys constant voltage and current until battery is full.it will then go into a float charge mode) I need to put volt meter and current clamp meter on the leads from the charger to the power socket and see what happens after 30 minutes. as for not connecting the ground lead of charger to battery,on the net it said it would damage battery monitoring system on car(I think the battery monitoring system is connected as close to the battery as possible ie on both terminals on battery,if it is like other battery monitoring systems in industry I have seen ) I will try to look at battery to see if I can see any small cables going to it,(most manufactures monitor the battery for the start/stop system on car ie the car will not operate stop/start if battery voltage is to low,or if it has stopped for a long time when elect loads are high it will auto start to charge battery up) agm batterys are a lot better for this type of use as they have a better d. o. d. (depth of discharge) and can recover quicker that's why they are used in back up systems and off grid power systems, solar and wind.

 

[dpoynton]

Anyone know why you shouldn't connect the negative charging lead to the battery?

Until recently we had a 56 plate Cayman S, bought it at three years old, 10k miles, presumably on its first battery.

We sold it at ten years old, 41k miles, still on same battery.

Used a ctek charger/conditioner until it gave up then a Halfords charger/conditioner more recently, connected to both negative and positive terminals on battery, charged it every two weeks if the car had not been used, never had a problem.

David

 

[rich mich]

the last boxster I had a 987 ,06 plate used to have a smokers pack in it, so that socket was live all the time ,(that's where I used to connect the charger) I think with the 987 series that they had a normal "WET" lead acid battery and did not have stop start,i don't know if that car had a battery monitoring system,and the replacement batterys did not need to be programmed to car ,as i put a bosch battery on mine when it was about 5 years old,(I know with modern ford cars they use a smart alternator which will dump a lot of current into battery straight after start up,120-140 amps,to get battery charged up quickly,and when the car is charged will reduce this current,to match the loads on car,all done by the ecu, all to do with reducing loads on engine (drag) That's why most car manufactures have gone to electric power steering ,etc)

 

[terry993]

Hi all

interesting replies following on from this I wonder why the majority of good battery charges supply an eyelet lead that is connected directly to both terminals of the battery.

So what is the definitive answer to directly connect or not?

would be nice to get some feed back from Porsche and mainstream battery charger manufactures such as Ctek.

All the best

terry

 

[rich mich]

just found some info about negative connections
www.w8ji.com/negative_lead_to_battery.htm

 

[mpt964]

I use a CTEK charger and plug it into the 12v cigarette lighter socket in the centre arm rest. Seems to work fine, being doing this for 2 years

 

[Terry]

The manual is pretty clear on this, if you are making a direct connection to the battery area, the positive lead should be connected to the positive battery terminal and the negative lead to the ground post which is on the other side of the underbonnet area.

 

[jockmog]

I use a Ctek with the +ve connected to the battery post via an eyelet and the -ve eyelet screwed to the battery retaining strap which saves having to extend the lead over to the -ve post. The "female" plug is permanently connected to the car and I simply plug in the "male" when I want to connect the conditioner.