Ctek Battery Charger / Maintainer

[aboulfad]

@Tomm3 , first our batteries aren't LIPO, they are LifePO4, google it you'll learn something. Second, all LifePO4 chargers have an optimize/maintenance mode. Third, here's the BMW doc on our batteries: https://www.dropbox.com/s/yr8ohfcn71...ttery.pdf?dl=0

[Tomm3]

If the charger has a "Storage" function then it's perfectly ok!
I would just connect a voltmeter to the battery while charging and check the voltage.
It should be close to nominal 13,2v. If it's being kept higher then faster deterioration of the capacity will take place.

[aboulfad]

Originally Posted by Tomm3

If the charger has a "Storage" function then it's perfectly ok!
I would just connect a voltmeter to the battery while charging and check the voltage.
It should be close to nominal 13,2v. If it's being kept higher then faster deterioration of the capacity will take place.

During specific stages of charging the charging voltage has to be higher than the nominal voltage. In optimize mode, which is time limited, the voltage varies from 14.1 to 14.4 V in order to equalize voltage across lithium cells. Here's another reference to read https://en.m.wikipedia.org/wiki/Lith...Specifications

Charging LifePO4 batteries is complicated, as the device needs to also monitor temperature and many other parameters, they are normally equipped with a microp to do all this!

For reference, see the above BMW doc, as well any the approved LifePO4 approved trickle chargers (CTEK lithium, Optimate TM291) documentation. These trickle chargers are the most sophisticated on the market, and have 8 steps for charging and maintaining the LifePO4 batteries correctly and safely. They are probably the only two companies that sell consumer 12.8V LifePO4 trickle chargers!!! You first referred to our batteries as Lipo which is a completely different technology as you are well aware now,

Regards!

[Tomm3]

So, once again, those advices apply only if you want to maximise your battery life.
If you plan to keep the car just for 3-4 years then it doesn't probably matter that much.
Every kind of Lithium battery behaves more or less in the same way. Only details change like charging/discharging voltage.
The ideal conditions to store Li battery is cool place and low charge state (40%)
Every deviation from temp or charge state will shorten its life.
About the voltage you were referring - 14,1-14,4v that is the main charging cycle. Correct. It's normal. I was talking about trickle charge which takes place after the main charge is finished and lasts as long as the battery is connected to the charger (can be even few months). That voltage is important. It should be about 13,2v. Then the charge state is only about 50% and it's perfect for storage.
Go and measure your voltage after 24-48 hours while connected to CTEK to see if you are nice to your battery.

http://www.mpoweruk.com/storage.htm
http://batteryuniversity.com/learn/a...tore_batteries

[mdefalco25]

Any more updates to charging battery with the Ctek? I just picked one up for the winter and have heard from majority it's the best charger for our batteries. Just want to make sure I cat set it and forget it over the winter. Thanks!

[Jockey]

Originally Posted by mdefalco25

Any more updates to charging battery with the Ctek? I just picked one up for the winter and have heard from majority it's the best charger for our batteries. Just want to make sure I cat set it and forget it over the winter. Thanks!

Yep, hooked mine up for 8 straight months. Came home, unplugged it and the car started right up with no problems.

[mdefalco25]

Sounds good! Everything I've read said it's a set it and forget it so was hoping that's the case. Thanks!

[Jkkl2001]

According to CTEK, the CTEK Lithium US is the only charger that's ideal for the 2015+ M3 & M4 utilize a 69aH Li battery.

[KevinM]

If anyone is interested, I received my BMW (Ctek-made) charger today; link earlier in the thread (although I ended up just buying it through my dealer). True to advertising, it is a dual charger and works with both lead and lithium batteries. This is nice for those of us that have both in our garages. I have not found the same battery marketed by Ctek without the BMW label. However, it is not much more expensive then the Ctek lithium-only version.

[G35POPPEDMYCHERRY]

what happens if you don't use this charger for 4 months?

[G35POPPEDMYCHERRY]

how do u set this up. plug it in first than clamp + the -. or clamp first. then plug in? do you have to press any buttons?

[mdefalco25]

Connect under hood to positive and negative terminals. Plug it in and then walk away. Dishes done. Has fail safes built in and will adjust accordingly to what battery requires.

[G35POPPEDMYCHERRY]

can you close the hood. aka put it down but dont latch it. the neg terminal isnt touching. but the postivie looks close to the hood. if it touches is that a problem?

[Deteria]

For those that use this charger, does it get very hot to the touch in stage 2?

[kerkiraios00]

Is there a certain model you guys bought or they just make one model ?

[Deteria]

Originally Posted by kerkiraios00

Is there a certain model you guys bought or they just make one model ?

CTEK (56-926) LITHIUM US 12 Volt Fully Automatic Lithium Ion Phosphate Battery Charger https://www.amazon.com/dp/B00EUF6UM8/ref=cm_sw_r_cp_apap_dbsadlgnBsKWX

[tcharged]

I have a Noco G3500 charger with lithium charging capabilities - would this work for my M3 or should I purchase a CTEK?

[parabmw]

I have a porsche dual mode maintainer. Suppose to be rebranded ctek.
This should still work on m4?

[parabmw]

Originally Posted by G35POPPEDMYCHERRY

can you close the hood. aka put it down but dont latch it. the neg terminal isnt touching. but the postivie looks close to the hood. if it touches is that a problem?

Can you close the hood?

[G35POPPEDMYCHERRY]

Originally Posted by parabmw

Can you close the hood?

I found it best two put to microfibers on folded up on the hood latches. this will allow the hood to be slightly open and eliminates the potential of the contact between the leads and hood.

[Alvinized52]

Originally Posted by parabmw

Can you close the hood?

Better if you dont so you dont forget its plugged in. Although i was able to close mine cuz i have carbon fiber hood... but i almost forgot it was plugged in one time. So now i always just leave hood up.

** i have BMW branded CTek charger.

[KevinM]

Originally Posted by tcharged

I have a Noco G3500 charger with lithium charging capabilities - would this work for my M3 or should I purchase a CTEK?

Any lithium battery tender should work, although I'm not familiar with the brand.

Originally Posted by parabmw

I have a porsche dual mode maintainer. Suppose to be rebranded ctek.
This should still work on m4?

Yes. CTEK makes the BMW-branded dual mode charger as well. The only reason I bought the BMW-branded version was that I could not find a dual mode CTEK version.