Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Model
Stock
Porsche 911
991 : 2011- 13
997 : 2004- 75
996 : 1997-2005 30
993 : 1993-1998 4
964 : 1989-1993 3
Carrera 3.2 : 1983-1989 2
Carrera SC : 1977-1983 1
930 Turbo : 1975-1989 0
Early 911 : 1964-1977 2
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 14
Cayman : 2005- 17
Cayenne : 2003- 3
Macan : 2014- 2
Panamera : 2009- 2
912-914-924-928-944-968 2
959 - CarreraGT - RaceCar 0
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [991] 2011-Current
Porsche 911 [991]
911 [997] 2004-Current
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message
toptime
Newbie


Joined: 25 Jun 2018
Posts: 31



PostPosted: Sat Feb 16, 2019 5:11 pm    Post subject: Trickle charge at 15.5v ? Reply with quote

Hi everyone,
I just noticed that my 07 C2 is trickle charging at 15.5v
The charger is an Aldi smart charger / conditioner which shows the charging voltage. I’ve been using it since the start of the winter and it has been working fine but I’m sure it was charging at less the 14v when I used it last.
I’m assuming the voltage is slightly higher as the current is now low as it trickle charges.
Anyone have any experience with this? Or maybe the same voltage on the same charger? Seems a bit high to me........
 
  
View user's profile Send private message
   
kurlykris
Indianapolis


Joined: 30 Jun 2014
Posts: 2373
Location: Warwickshire


PostPosted: Sat Feb 16, 2019 6:12 pm    Post subject: Reply with quote

Can you check the voltage at the battery terminals with a digital Multimeter to verify the actual voltage ?
You`ll boil the battery at anything over 14.4v and it will be gassing nooo
_________________
1998 996.1 C2 3.4 with "Aerokit Cup"
2006 Boxster S sport chrono
2010 Mercedes E350 AMG Sport

 
  
View user's profile Send private message
   
toptime
Newbie


Joined: 25 Jun 2018
Posts: 31



PostPosted: Sat Feb 16, 2019 6:38 pm    Post subject: Reply with quote

Yes that was my concern Surprised
As soon as I unlock the car (and put a load on the battery) the charger display drops to 12.9v and I measure the same with the mm. If I switch the charger off the battery voltage is 12.7v which is fine.
Switch the charger back on and it shows 12.9v then rises back to 15.3v with 5 to 10 mins......
Weird.......
Something to do with surface charge maybe?
 
  
View user's profile Send private message
   
kurlykris
Indianapolis


Joined: 30 Jun 2014
Posts: 2373
Location: Warwickshire


PostPosted: Sat Feb 16, 2019 7:02 pm    Post subject: Reply with quote

You`ll only see the surface charge after you have disconnected the charger, it should only be about 0.5v, I usually put a small load on the battery for 30 seconds or so, then leave it for an hour or 2 before I test the open circuit/actual voltage of the battery.
It sounds like the voltage regulator is fubarred in your battery tender to me nooo
_________________
1998 996.1 C2 3.4 with "Aerokit Cup"
2006 Boxster S sport chrono
2010 Mercedes E350 AMG Sport

 
  
View user's profile Send private message
   
toptime
Newbie


Joined: 25 Jun 2018
Posts: 31



PostPosted: Sat Feb 16, 2019 7:21 pm    Post subject: Reply with quote

Sounds like it’s time for a new charger then!
Ironically it’s sat at 13.7v for the last hour.!
 
  
View user's profile Send private message
   
deMort
Long Beach


Joined: 21 Mar 2015
Posts: 6526
Location: Brighton


PostPosted: Sat Feb 16, 2019 8:00 pm    Post subject: Reply with quote

If the charger is over chargeing the battery then the battery will be warm to the touch .. if a severe over charge then it will get hot and you will have an acrid smell .. it will make your eyes water .

Ive seen it .. battery was the shape of a balloon .. we couldnt go near the car for the smell and we pushed it outside to cool down .. full protective gear and we finally removed the battery once it had cooled down .. scary stuff !

That was an alternator fault pushing over 18 volts into it though .

997 and they can charge upto 16 volts .. its normally when a battery is very dead or a possible fault .. but at that voltage it doesnt seem to boil a battery .. close to the edge though in my books .

basically what im saying .. see how hot the battery is .. if cold then dont worry .. if its getting warm then the charger is faulty or the battery is .

IMHO anyways .
_________________
.

My Daughter's Crowdfunding page Here

Mechanic

7pm - 9pm

Now At An Indy.
 
  
View user's profile Send private message
   
toptime
Newbie


Joined: 25 Jun 2018
Posts: 31



PostPosted: Sat Feb 16, 2019 8:19 pm    Post subject: Reply with quote

Thanks for the replies guys. Battery is not warm, no smell and no signs of anything untoward. If the charger didn’t have a readout I would have no reason. To think anything is wrong.
Really don’t want to risk cooking anything though so I think I’ll get another one.
 
  
View user's profile Send private message
   
Luddite
Spa-Francorchamps


Joined: 18 Dec 2018
Posts: 253
Location: Scotland


PostPosted: Mon Feb 18, 2019 12:32 am    Post subject: Reply with quote

OK, I have zero knowledge of gel batteries, and my info only really applies to lead acid batteries thus may be of little use here..

With the alternator charging the battery 13.2 volts and under too low 13.8v to 14.5 OK above 14.5v too high.

In the case of lead acid batteries, if charging or discharging heavily they give of EXPLOSIVE gas and if my poor memory is correct the gas is Hydrogen..? I have seen the aftermath of an accident where a battery exploded blinding an engineer in one eye as the result of the gas build up external to the battery being exposed to a flame.. though any kind of spark caused by disconnecting a charger lead crocodile clip before switching the charger off can cause an explosion if the battery is gassing, same goes for a loose clamping arrangement on one of the terminals and the ign key turned to start position...creating a spark at the terminals...

Battery fully charged taken off the charger and left disconnected from any circuit for approximately an hour and voltage readings taken across the battery terminals.

12.72 volts 100% efficient 12.52v 80% 12.3v 60% 12.12v 40% 11.9v 20%

Taking voltage measurements with the battery connected in the car can give readings that mislead given the demands of the circuits connected, often referred to as parasitic losses. A worst case scenario might be measuring across the battery terminals with the starter turning the engine over and not starting, where a reading of 10v to 10.6 might be considered average, though could be as low as perhaps 4v if the battery is on it`s last legs but still able to turn the engine over, all be it slowly..

No doubt this info is well out of date, but may just be of use to those with older Porsches running lead acid batteries...?
 
  
View user's profile Send private message
   
toptime
Newbie


Joined: 25 Jun 2018
Posts: 31



PostPosted: Mon Feb 18, 2019 7:10 am    Post subject: Reply with quote

So, I exchanged the charger for a new one yesterday. I checked the charger after about 6 hours and it was showing 13.7v. Checked again this morning and its back to 15.3v Question
The battery is a Bosch S5 and all appears well......
 
  
View user's profile Send private message
   
jl-c
Silverstone


Joined: 22 Jul 2013
Posts: 129
Location: Shropshire


PostPosted: Mon Feb 18, 2019 10:06 am    Post subject: Reply with quote

You don’t say what you replaced it with. Much as I like Aldi biscuits I would not trust my Porsche to an Aldi branded battery charger. Buy ( or borrow, I guess) a CTek. Totally your choice but not a road I would go down. Things are cheap for a reason...... Surprised
_________________
Porsche Carrera 2S 2005 black fully Hartech'd!, BMW Z4 coupé 2007 blue, Mazda Eunos 1996 yellow, VW Passat 2014 black.


We all do silly things/make mistakes, it's how we deal with them that sets us apart from animals and Americans.
 
  
View user's profile Send private message
   
toptime
Newbie


Joined: 25 Jun 2018
Posts: 31



PostPosted: Mon Feb 18, 2019 11:15 am    Post subject: Reply with quote

I replaced it with like for like from Aldi. The Aldi / Lidl units get very good reviews and are used by owners on the premium car forums. It was the reviews that made me aware of them and so I picked one up to give it a try.

I also noticed on the back of the packaging of the new charger that the charging end voltage is between 15.1v and 15.5v so this answers my original question.

Thanks all for your help.

Last edited by toptime on Mon Feb 18, 2019 12:34 pm; edited 1 time in total
 
  
View user's profile Send private message
   
MisterCorn
Long Beach


Joined: 08 Jan 2011
Posts: 6966
Location: Nottingham, England

2004 Porsche 996 Turbo

PostPosted: Mon Feb 18, 2019 11:21 am    Post subject: Reply with quote

I don't know my people rate CTEK chargers so highly. They are certainly OK, but of the two trickle chargers I have ever had fail on me, both have been CTEK ones. They are generally OK, but certainly not 'fit and forget'.

MC
 
  
View user's profile Send private message Visit poster's website
   
jl-c
Silverstone


Joined: 22 Jul 2013
Posts: 129
Location: Shropshire


PostPosted: Mon Feb 18, 2019 11:26 am    Post subject: Reply with quote

Just speak as you find, you obviously fell unlucky. I have 4 CTek’s which are all in use most of the time (if not on a car, re-conditioning spare batteries) and have been absolutely faultless. ( so that should put the kiss of death on them! ) Floor
_________________
Porsche Carrera 2S 2005 black fully Hartech'd!, BMW Z4 coupé 2007 blue, Mazda Eunos 1996 yellow, VW Passat 2014 black.


We all do silly things/make mistakes, it's how we deal with them that sets us apart from animals and Americans.
 
  
View user's profile Send private message
   
maph
Monza


Joined: 01 Feb 2017
Posts: 159



PostPosted: Mon Feb 18, 2019 4:42 pm    Post subject: Reply with quote

OP, glad you are sorted Thumb

Regards C-tek my first charger stopped working with little use (mode button packed up, a common fault apparently) making it impossible to use.

I now have two newer C-tek MSX 5.0s, but I am not totally convinced with these either. I was charging one of my other cars in storage (BMW M Coupe) and it was all lit up with a full set of green lights, doing it's pulse stage apparently....... went to take it out and the battery was completely stuffed.

Reconnected it, put it in a restore mode, checked it a few days later, again all green lights, happy days....... no battery still dead.

New battery and has not skipped a beat since, just do not trust the c-tech's reporting any more, not so smart me thinks.

Again, I am probably unlucky but I agree that their reputation seems higher than the quality of their products.
_________________
2012 997.2 Turbo S - ES650
 
  
View user's profile Send private message
   
Oggie
Newbie


Joined: 15 Aug 2018
Posts: 5
Location: Western Australia


PostPosted: Tue Feb 19, 2019 7:14 am    Post subject: Reply with quote

Charging at 15.5V isn't unusual for a "smart" or "multi-stage" charger. On some chargers (I'm not familiar with the Aldi charger) have a stage called equalisation which will charge at a higher voltage of between 15V and 16V for a period to reduce sulphation and stir up the electrolyte to stop stratification that can occur in wet type lead-acid batteries.

For more info, there is an article on the charging stages here: http://www.chargingchargers.com/tutorials/charging.html
_________________
'02 996 Carrera Cabriolet
'99 986 Boxster
 
  
View user's profile Send private message
   
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Page 1 of 1

 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum
You cannot post calendar events in this forum