Optimate or C-Tek car battery charger?

[TheChamp]

Just over 12V with the car running doesn't seem right, turn on all lights, demister etc and test again. If the voltage drops any further you definitely have an issue.

Something was most probably on at the time.

 

[Foxhound5366]

Something was most probably on at the time.

Well I'd turned the aircon and car radio off, but the LED daytime running lights can't be turned off. Could that explain it?

 

[TheChamp]

Well I'd turned the aircon and car radio off, but the LED daytime running lights can't be turned off. Could that explain it?

No, the voltage drop should be very minimal on LED, maybe some other interior lights or some other auxiliaries. Going from 14V to 12V is a massive drop so it must have been something significant.

I usually put the multimeter on the windscreen and monitor it from the inside while the car is running, I know the fan, aircon and radio are the biggest culprits. There must be a couple of things running in the background on your car.

 

[ProfA]

Well, we're in the final stage of charging and nothing has blown up yet:
View attachment 996106


One little tip is that some cars have a dedicated "negative connection" to attach things like this charger or jumpstart cables to, like this (on my Polo there's a bolt marked with a - sign). Apparently if you try it directly to the battery's negative terminal you can fry your car's electronics:

View attachment 996108

Utter nonsense. That negative post is only there because some batteries are difficult to get to. My merc has separate negative and positive terminals away from the battery. I have charged numerous times directly on the battery with absolutely no issues.

 

[Foxhound5366]

Utter nonsense. That negative post is only there because some batteries are difficult to get to. My merc has separate negative and positive terminals away from the battery. I have charged numerous times directly on the battery with absolutely no issues.

So you're speaking based on your experience as a trained mechanic? Or based on "I did it and nothing bad happened"? Not saying you're wrong, but not saying that "I played Russian Roulette dozens of times and I'm still here so now I see it as a safe children's game" is sound logic

 

[ProfA]

So you're speaking based on your experience as a trained mechanic? Or based on "I did it and nothing bad happened"? Not saying you're wrong, but not saying that "I played Russian Roulette dozens of times and I'm still here so now I see it as a safe children's game" is sound logic

have been charging like that for 10 years. you are talking sht.

 

[Foxhound5366]

have been charging like that for 10 years. you are talking sht.

Wasn't me who said it, dipshit. Try reading, you might get somewhere. The VW Master Technician who came over was the one who shared that little tidbit ... and maybe he's full of **** too lol.

 

[ProfA]

Wasn't me who said it, dipshit. Try reading, you might get somewhere. The VW Master Technician who came over was the one who shared that little tidbit ... and maybe he's full of **** too lol.

well then you are both talking sht dipsht.

 

[Def-e-nition]

C tek . Period.

Works like as bomb.

 

[The_Traveller]

Utter nonsense. That negative post is only there because some batteries are difficult to get to. My merc has separate negative and positive terminals away from the battery. I have charged numerous times directly on the battery with absolutely no issues.

it would be wise to tell us which Merc model this is .

A y2k model is very different to one of the later gen’s .

 

[ProfA]

it would be wise to tell us which Merc model this is .

A y2k model is very different to one of the later gen’s .

w203.

 

[The_Traveller]

w203.

touché

Foxhound's Polo(ny) probably has much more electronics than your Merc.

 

[Foxhound5366]

well then you are both talking sht dipsht.

Ok dude, I realised I could check the owner's manual and found this:


Soooo ... I don't know if "incorrect condition evaluation" could lead to damage or malfunction for the electronics, but it DOES seem clear that one shouldn't connect directly to the negative terminal and there actually may be some negative consequences if you do that.

 

[ProfA]

touché

Foxhound's Polo(ny) probably has much more electronics than your Merc.

You base this tidbit of info on what exactly?

 

[ProfA]

Ok dude, I realised I could check the owner's manual and found this:

View attachment 1013548
Soooo ... I don't know if "incorrect condition evaluation" could lead to damage or malfunction for the electronics, but it DOES seem clear that one shouldn't connect directly to the negative terminal and there actually may be some negative consequences if you do that.

Doesn't know the difference between jumping a car and charging the battery on a car. Perhaps you should quit now.

 

[Foxhound5366]

No, the voltage drop should be very minimal on LED, maybe some other interior lights or some other auxiliaries. Going from 14V to 12V is a massive drop so it must have been something significant.

I usually put the multimeter on the windscreen and monitor it from the inside while the car is running, I know the fan, aircon and radio are the biggest culprits. There must be a couple of things running in the background on your car.

So I left the car off the charger overnight and started the car and measured the voltage and you'll be delighted to see the alternator is charging the battery now:

 

[Foxhound5366]

Doesn't know the difference between jumping a car and charging the battery on a car. Perhaps you should quit now.

Ok Profa, you must be right. Now jog on.

 

[AfricanTech]

Aaaaaaand final update, she works.

Charger in maintenance mode:
View attachment 996162

After disconnecting charger, with only a 1 hour top-up, battery was at a perfect 12 volts (up from 11.7 before).

did you have to put it in any specific mode or just 'plug and play'

I'm on the cusp of deciding between this and the Optimate 5

Have a Nissan Qashqai that's been standing throughout lockdown so ja....

 

[Neuk_]

I am late to the thread but I have both an Optimate and CTEK, well a Ferrari rebranded CTEK which is basically an MXS3.8. Both work great, I use the Optimate on my MkI Golf pretty much permanently and the CTEK is used when we go away and leave one of our daily drives at home for a few days. I'll support CTEK in the future as they make great products and a good friend is the local distributor.

 

[Foxhound5366]

did you have to put it in any specific mode or just 'plug and play'

I'm on the cusp of deciding between this and the Optimate 5

It's just plug and play. So after loadshedding it comes right back on and keeps going. Apparently if you've got a luxury car battery (Absorbent Glass Mat - AGM) then you need to change into a different mode, but for my Polo's EFB battery it just goes directly into charging. It's worked well all these months and the car hasn't had another flat battery, so problem solved I guess. I chose it after I saw a guy online talking about how his device had been going for years.