Best Trickle charge for GT3RS - Page 1 - 911/Carrera GT - PistonHeads UK

Hi , anyone advise on best charger for my 997 rs whilst it rests in winter ... will be using it when and if weather permits ! Would a Optimate sp3 be ok as i already have one . Cheers.

iirc i think the optimate 3 rating is not high enough for a Porche though it maybe good enough as a trickle charger. I think you need a minimum of a optimate 5. http://www.optimate.co.uk/optimate%203+.htm optimate 3+ recommended for AGM / MF, STD, GEL and spiral cell batteries from 2Ah to 35Ah http://www.optimate.co.uk/optimate%205.htm optimate 5 recommended for AGM / MF, STD, GEL and spiral cell batteries from 7.5Ah to 120Ah optimate 3 spec " ...Recommended for all 12V lead-acid batteries from 2Ah to 45Ah, although it can also maintain larger batteries it will just take longer to charge ..." The ctek are another alternative, but note they do not work with AGM unless on winter mode - trackcars tend to use AGM batteries. The optimates charge every other 30mins which stops batteries like AGM ones overheating and warping. Several of mine did this before I read the detail in ctek/Optimate manuals.

Slightly concerned as I have been using the same trickle charger on my recently acquired GT3 as I did on my previously owned TVR T350. The car is getting regular weekend use but using the trickle charge is probably out of habit/comfort. I am using a AccuMate multi-stage charger which states use on all 6V and 12V lead acid batteries. I am also plugging into the cigarette lighter socket. Should I still use this charger on the GT3

Optimate 3 is still ok for trickle charging - it just takes longer according to the spec sheet - the recommended one is the optimate 5.

tjlees said: The ctek are another alternative, but note they do not work with AGM unless on winter mode - trackcars tend to use AGM batteries. I'd say that the vast majority of track use GT3s are just on standard OEM, Bosch or Varta actually. Exotic batteries tend to be quite a long way down the list for upgrade popularity in my experience, though I have heard of a few out there. To answer the original question though - Ctek make the Porsche badged one so something from their range is a pretty safe choice (mine is currently plugged into an Ctek MXS 5.0 but I haven't had that long and can only say no issues thus far).

griffgray said: Slightly concerned as I have been using the same trickle charger on my recently acquired GT3 as I did on my previously owned TVR T350. The car is getting regular weekend use but using the trickle charge is probably out of habit/comfort. I am using a AccuMate multi-stage charger which states use on all 6V and 12V lead acid batteries. I am also plugging into the cigarette lighter socket. Should I still use this charger on the GT3 I'm pretty sure the cigar lighter isn't active once the car's turned off, possibly after a delay period - if so, then your charger's not doing anything at the moment.

I have the standard one supplied by Porsche on the RS . Into the cigarette light socket. Has been perfect for years.

DiscoColin said: tjlees said: The ctek are another alternative, but note they do not work with AGM unless on winter mode - trackcars tend to use AGM batteries. I'd say that the vast majority of track use GT3s are just on standard OEM, Bosch or Varta actually. Exotic batteries tend to be quite a long way down the list for upgrade popularity in my experience, though I have heard of a few out there. To answer the original question though - Ctek make the Porsche badged one so something from their range is a pretty safe choice (mine is currently plugged into an Ctek MXS 5.0 but I haven't had that long and can only say no issues thus far). I use my charger across several cars - so some cteks maybe perfect for the porsche but not for my track car that has a lightweight AGM battery. NB The Ctek MXS 5.0 has a selectable mode specifically for AGM Odyssey and optima batteries. Though I like the fact that I just plug in the optimate 6 and the electronics work out what state the battery is in and whether or not its connected to the car (to ensure the car's electronics are preserved) before automatically selecting the charging programme. Additionally it worth checking the manuals :-). For instance the Ctek 3.6 and optimate 4 would be ok as a trickle chargers, but would struggle to charge a 80ah battery whereas the ctek 5.0/optimate 5 would have no problem. Also the detail behind the charging programmes - to see which one takes your fancy Ctek instructions http://www.ctek.com/gb/en/page/support/manuals optimate instructions http://www.optimate.co.uk/optimate%20technical.htm

Ahh...it does rather depend on which battery you're running. To best of my knowledge, there are two factory fit batteries for a 997.2 GT3 RS. If it is the standard Moll Lead-Acid (Pb-H2SO4), Porsche part #999.611.070.00, then a CTEK charger in normal mode should keep this in good health through the 12V port, or if you prefer, directly coupled to the terminals. My GT3 RS, came with the Moll, and is currently on a CTEK MXS 5.0 active through the 12V port - it is NOT a cigarette lighter - located to the left of the center console on RHD cars, in the passenger footwell. If you elect to go with the Li-ION, Porsche part #997.611.020.00, then the ensuing ex Rennlist is probably sage advice: from this thread: http://forums.rennlist.com/rennforums/997-gt2-gt3-... post 14, credit Steve W: "You cannot store the car with the lithium connected over the winter or you'll destroy it withn 2-3 weeks when it becomes completely discharged. Once a lithium cell is discharged completely, it is non-recoverable. The Porsche lithium battery is an 18Ah battery, consisting of four 3.6v 18Ah LiFePO4 cells in series, netting a 14.4v 18Ah battery. With the car in sleep mode, the car consumes just under 1Ah per day. Sleep mode is the mode of least power consumption and is achieved by locking the car. If you leave your doors unlocked, you can expect the power consumption to double or triple to 2-3Ah daily. There is an beeping alarm built in warning you when the voltage gets too low and requires you to get the battery charged up ASAP, either by running the car or with a proper charger. Even with a charger, the proper way to charge lithium batteries is with a smart charger that balance charges each of the internal four cells to they have equal capacity. RC and EV hobbyists know this fundamental all too well. But unfortunately the Porsche battery does not have a balance charge port so eventually the the cells get highly imbalanced, where you can have one cell storing 18.5Ah, and another only 5Ah, etc., netting the battery capacity as nothing higher than the capacity of the lowest cell. Battery packs such as in your laptop, cordless power tools, or your Prius or Tesla contain circuits that maintain proper charge balance of the cells so this doesn't happen, and unfortunately the Porsche battery also does not have such circuitry. There is also the danger of overcharging a lithium cell which can cause an explosion or fire. With a lead acid battery, the excess current/voltage ends up boiling the electrolyte. In a lithium cell, the electrolyte is part of the paste that contains the lithium which overheats and puffs up the cells, causing the type of explosions and fires you hear about with the Fiskser Karmas, Chevy Volts, the Boeing Dreamliners, exploding laptops and iPhones, etc. You may have also heard about the GT3s that had their lithium batteries just unexpectedly explode into a fire while it was in a dealer service department, probably because it was connected to a high current standard battery charger. I would remove the lithium battery, and install your standard battery and connect a standard battery maintainer to the car to keep the battery topped instead. A CTEK or Battery Minder is good as they have a desulphating mode for lead acid batteries. But do not use such maintainers with lithiums or the desulphating mode destroys lithium cells. If you really don't want to swap the batteries, then just disconnect the cable from the battery and leave the trunk lid open and unlocked. If you prefer not to disconnect or remove the battery, the alternative is to use a battery maintainer connected to the car to provide the maintenance current the car is drawing constantly. Some lithium battery makers claim a the tender made by the brand Battery Tender can do the job as they are just simple maintainers without the desulpahtion mode. CTEK recently came out with a lithium charger/maintainer claiming to be able to maintain the cells of a vehicle with a lithium battery, but neither of them utilize the traditional balance charge ports to keep the cells in balance, I would be skeptical of their operation for the reasons outlined above." Edited by BMCG on Sunday 17th November 20:02

Thanks everyone... I think .... gone right over my head now. ! . Have ordered a ctek recommended by my dealer , so hopefully will be ok but I will try to use every 2-3 weeks when weather is ok ... Any excuse !?

BMCG said: My GT3 RS, came with the Moll, and is currently on a CTEK MXS 5.0 active through the 12V port - it is NOT a cigarette lighter - located to the left of the center console on RHD cars, in the passenger footwell. Tiny footnote on that is that while it is fine for charging through either, the handbook says to use the cigarette lighter rather than that one if you ever need to run the tyre compressor. While we are on the subject - does anyone know why? Presumably the ciggy lighter is specced to put out more ampage?