[mike sevel]

Recently purchased CTEK trickle charger. Two questions:

1. After several hours of charging, the half-battery icon light (active charging) is still on. If I unplug the charger and wait a few minutes and plug in again the full battery icon light is on. Voltage test shows 12.7+ volts. Is this normal?

2. Today I connected the leads to the under hood connections, and, before I plugged it in, the mode light was illuminated. Does that indicate a short in the battery or charger?

Pls advise. Thanx,
Mikey

[tcphoto]

I don’t have that charger but am curious if you used the under the hood connections initially. BMW doesn’t recommend charging a battery from the trunk. Secondly, how old is your battery and did the problem start when the weather started turning cold? If so, it may be time for a new battery.

[AllBlackBimmer]

I use a ctek 3300

Great product.
It may take a few mins before it recognizes the charge of your battery, so don’t plug and unplug and plug back in thinking it will pick it up immediately.

I use the under hood connections and hardwired the quick connect adaptor to positive and negatives post to make connection super easy.

A trickle charger will cycle on and off when your battery gets to like 90% or something so it doesn’t overcharge your battery.

Once again great product, I’ve used mine for 3+ years with great success. I have left my car plugged in for 2-3 weeks at a time before. I have also unplugged it, gone and driven my car, and then came home and plugged it right back in.

Many companies, including bmw, Ferrari, Lamborghini, etc offer “brand specific “ chargers that are literally cteks with a Ferrari sticker on it at 25x the price.
I wouldn’t worry about it. Connect it correctly (under hood), plug it on, put it on correct mode and forget about it.

Edit: just went out and plugged my car in. I connected to the car before I plugged the charger into the wall, the yellow “mode” button did illuminate as it should, and always does. Yours is operating normally, so no worries. Just enjoy extended battery life and no dying from the cold and not being driven!

[ctuna]

5 o 7 hours to top off on my ctek 4.7
Ends up very close to 13 volts.

You are suppose to let it run till the green light is on.

[wdb]

I have a CTEK MUS 4.3 (two actually) and a 2007 E93 328i with gel (AGM) battery. Also a 2007 Z4M Coupe with gel battery. It took the charger almost 10 days to fully cycle through all of its modes and bring the battery back on the M. It still hasn't reached 'trickle' mode on the 328i, but it has made a huge world of difference in terms of what works and doesn't work on the car, how easily it starts, how smoothly it runs, etc. and so on. If you have a gel (AGM) battery make sure you set the charger for it, makes a huge difference.

[nhhiep]

I am using this Battery Tender 3A for my E93 in winter

https://www.costco.com/Battery-Tende...100241973.html

[bluewater328]

I use the BMW branded version for the past 3 years and it's been great. Yes, try and wait till the green battery is illuminated for a max charge. However, in the instructions, I want to say that anything past a certain stage (IIRC it was 4) you can safely drive off.

[SJM67]

i got this battery tender off amazon on black friday for 12.99...has multiple functions and protection for ALL type batteries. used it last weekend to top off my AGM battery ..works awesome.

[wdb]

Repackaged or ripoff CTEK unit.

[nsjames]

a trickle charger is usually 1 amp.

1 amp isn't much. say your battery has a 100ah reserve and it's 50% discharged.

it will take a 1 amp charger 50 hours to charge that battery.


and before everyone jumps on the "it doesn't work like that!" train, this is a very simplified explanation here.

[wdb]

CTEK is a trickle charger only after it gets done reconditioning. Best have it plugged into a proper extension cord.

[AllBlackBimmer]

Originally Posted by wdb

CTEK is a trickle charger only after it gets done reconditioning. Best have it plugged into a proper extension cord.

Great point!
Using these type of devices with extension cords is not always recommended, and if you are using one, make sure it has the correct amp rating!! Something many people don't even consider when using extension cords.

CTEK 3300 is highly recommended and worth the $50 bucks. I would not cheap out and buy a cheap one and risk frying my car/battery/IBS with all the electronics these cars have on them!

[spazzz]

Originally Posted by nhhiep

I am using this Battery Tender 3A for my E93 in winter

https://www.costco.com/Battery-Tende...100241973.html

I use the same one. It charged my 6 year old Optima in my outside daily in 15 minutes yesterday.
Takes the year old 535xi AGM a little longer, well actually a lot longer