CTEK Charger and the X5?
 

I just wondered about the safety of connecting a CTEK MXS 5.0 charger to the BMW X5 engine bay terminals to charge and condition the battery every month or so.

Normally i have removed the Battery completely from the Vehicle and charged it on the workshop bench, then re fitted it.
(I have done this, because of the some of the horror stories i have heard about people killing the Instrument Cluster when Jump Starting etc)

The CTEK puts out 14.7 volts @ 5 Amps for most of its charging cycle
Although its says it can put out 15.8 volts in Desulphation Mode.

Can anyone comment if this is Good Practice to keep our $$$ Batteries in top shape?
Or are there concerns with "In-Vehicle" charging?

Vehicle is driven daily, so it might be a waste of time doing this anyway?

Thank You

Not a CTek user, but I've been hooking up my Battery Tender low amp charger to the engine bay lugs since about Day 10 of owning this '01, nearly 15 years ago.

Never a problem...
GL, mD

Thanks motordavid, that is great to know.
Would you happen to know you Chargers output voltage and current?

Either way, the idea sounds safe enough.
I have noticed in BMW Dealerships, they all run tender leads to the showroom vehicles.
Well, our local dealer does anyway.

As you have done this for 15 years now, have you noticed a better than average life from your Battery?

SD -

No need to worry about voltage.
Just short of the charger going bad, it will go into trickle mode once it get's close to voltage. Then float/maintain. It should no ~cook~ your battery -- under the single assumption that the charger is good.

It's electronics though so things can go bad. Whether in 6 months or 6 years.

FWIW, I do hook up mine to give it a full absorption even now and then.
Look into their quick connects. I have those in all of the cars. So when I want to ~top it off~, I just hook it up via the already installed QC

If you use the car every day the chance of the battery sulfating is nil or none. Battery only sulfate if it sits from non-use.

Only time I use a tender on my X is during the winter when temps drops below freezing.

Oh, my concern wasn't the Battery, it was more any sensitive electrics in the BMW itself, that might not like an After Market charges voltages or pulses.

But from the sounds, seems ok to use.

Thanks upallnight, i appreciate what you are saying, although or X5 managed to kill a Federal Silver Calcium 900CCA 125RC Battery in just under 2 years.

So i am now wondering if this a good way to look after the 860CCA AGM battery i got to replace the calcium unit.

Can/Does the BMW alternator charge our Batteries to a 100% State of Charge?
Given enough driving time that is.

As posted before on this question, you can use a battery tender ("trickle charger") anytime your vehicle sits for an extended period of time. Mine sits on a charger 100% of the time. The constant 100% charged battery will last approx 50% longer than if you let it be drained by the alarm systems, constant demand that our vehicles draw when at rest, and short run cycles. Almost everyone agrees that having your vehicle on a battery tender will keep everything at 100%.

In my own experience, a BMW that sits 90% of the month, when put on a battery tender will have a battery that lasts 8+ years. Without one, the high drains and recharging cycles will kill it off in less than 3 years. AGM batteries will die off much sooner as their construction will not withstand multiple high discharge/recharge cycles. A slow drain over a few weeks followed by a high recharge will kill off a battery quickly. That is why most car batteries die off in three years. Parasitic draws only accelerate the problems, which is why you see lots of postings on this problem... Vehicles that are hard to start due to low battery voltage, often end up with other conflicting symptoms like multiple codes, error/warning lights on, all due to electrical issues and a dying battery. A VERY BAD COMBO and hard to diagnose.

Bigger is better (last longer) when it comes to batteries especially when they weigh in at 58# and you have to dig under everything and drag it out of the rear cargo area. You only want to do it once every 8 years....:bustingup

Now the question I have for the electronic wizards is "what is better for an X5? A battery connected and trickled charged constantly or a vehicle with the battery disconnected from the electrical system but on a tender?" I am beginning to think that having everything activated creates a potential issue long term on stored vehicles. Most car collections use a quick connect at the battery while on a charger standard practice. Thoughts? Or should I move this question to the SAE forum as it is totally theoretical? :popcorn:

RE: "Now the question I have for the electronic wizards is "what is better for an X5? A battery connected and trickled charged constantly or a vehicle with the battery disconnected from the electrical system but on a tender?" I am beginning to think that having everything activated creates a potential issue long term on stored vehicles. Most car collections use a quick connect at the battery while on a charger standard practice. Thoughts? Or should I move this question to the SAE forum as it is totally theoretical?"


^ Not an electrical tech here...old shade tree mechanic, and purely anecdotal.
Fwiw, I have had the '01 X or the '02 VetteVert on a Battery Tender brand maintenance charger for many years.

One of those cars is in the garage, in situ for several months per year.

I don't run the BT 24/7; I simply run it through an old fashion mechanical appliance timer set to come on for ~24 hrs a couple times per week, with the BT alligator clips attached to the underhood lugs, and electrical taped snugly so the passing mouse can't knock off a clip.

Have never had an 'electrical prob'/dead batt in either car over many years of doing this winter regime, to either of them. Whichever car it is, starts & runs fine 5 months after sitting.

I try not to overthink this stuff too much...;)
GL, mD

I've done that trick myself with a Deep Cycle 100AH Camping Battery
Only it was a 24hr timer just set to come on for 1 hour a day (4amp charger)

To answer the question regarding a battery on a daily driver, yes 3 or more weekly runs in a X5 of trips of more than 60 mins, will keep the battery within a full state of charge. Making the assumption that you are driving over 40 miles per hr average. Idling, short trip lengths, stop and go traffic with all the electrical loads on (lights, A/C, Blower motor, wipers, stereo pumping, etc) will NOT charge a battery but will in fact accelerate the drain on the battery. Nor will it allow the engine to burn off all the water (moisture) in the oil pan so the oil separator will freeze up as soon as winter comes back.

Wait, you live in the upside down world of the globe. You are in winter now, sorry. :nanana: