CTEK 5.0 Charger and a W212-Questions

[reflexboy]

I'm sure this has been asked many times before but I'm reading conflicting things.
I want to Recond and charge the battery in my W212 using my CTEK 5.0. CTEK says I don't need to disconnect it from the car and to connect it directly to the battery terminals. MB's owners manual says to "Only charge the battery using the jump-start connection point." Which is correct?

Also, in Recond mode, the CTEK apparent kicks out 15.8V but the MB owners manual states: "Only use battery chargers with a maximum charging voltage of 14.8 V."........Which one is right? I'd prefer just to leave the battery in situ but do not want to damage any sensitive electronic stuff.
I'm then also reading stuff relating to where to hook the charger up to with regard to the battery control module (BCM)
These CTEKs are meant to be fit and forget??

Any experience or pointers greatly appreciated.

 

[Mrhanky]

I'm sure this has been asked many times before but I'm reading conflicting things.
I want to Recond and charge the battery in my W212 using my CTEK 5.0. CTEK says I don't need to disconnect it from the car and to connect it directly to the battery terminals. MB's owners manual says to "Only charge the battery using the jump-start connection point." Which is correct?

Also, in Recond mode, the CTEK apparent kicks out 15.8V but the MB owners manual states: "Only use battery chargers with a maximum charging voltage of 14.8 V."........Which one is right? I'd prefer just to leave the battery in situ but do not want to damage any sensitive electronic stuff.
I'm then also reading stuff relating to where to hook the charger up to with regard to the battery control module (BCM)
These CTEKs are meant to be fit and forget??

Any experience or pointers greatly appreciated.

I have always just fitted the quick charge connectors. Never remove the battery just hook it up via the connector and switch to AGM and away it goes.

Never had any issues with my car either in recon or normal charge.

 

[reflexboy]

Just looked at my battery and it's a VRLA battery. So do I set the CTEK to 'Normal battery' or to 'AGM Battery'?

 

[190]

An AGM is a Valve Regulated Lead Acid battery so I would use the AGM setting.

Don't use the recondition setting as besides potential damage to the car that is probably what is called an equalisation mode intended to equalise the state of charge across individual cells in a wet cell battery and may also be designed to address acid strength stratification in wet cell batteries. I'd be surprised if it's even selectable when the charger is set to AGM.

Wet cells can stand high charge voltages for a time and will just need topping up with distilled water, where as if you overcharge a Valve Regulated battery it will eventually vent off resulting in loss of electrolyte which can't be replaced.

Do use the jump start connections.

 

[reflexboy]

An AGM is a Valve Regulated Lead Acid battery so I would use the AGM setting.

Don't use the recondition setting as besides potential damage to the car that is probably what is called an equalisation mode intended to equalise the state of charge across individual cells in a wet cell battery and may also be designed to address acid strength stratification in wet cell batteries. I'd be surprised if it's even selectable when the charger is set to AGM.

Wet cells can stand high charge voltages for a time and will just need topping up with distilled water, where as if you overcharge a Valve Regulated battery it will eventually vent off resulting in loss of electrolyte which can't be replaced.

Do use the jump start connections.

Thanks for the info. The recondition mode is selectable with an AGM battery, but as you suggest, I won't select that. Out of interest, why do you recommend using the jump start connections as opposed to directly connecting the CTEK to the battery posts?

 

[Mrhanky]

Thanks for the info. The recondition mode is selectable with an AGM battery, but as you suggest, I won't select that. Out of interest, why do you recommend using the jump start connections as opposed to directly connecting the CTEK to the battery posts?

The ctek is designed to be used with AGM batteries and this applies to the recon mode also. I have done a recon every year for the past three years with no ill effects on car or battery.

You can use jump connections but Imo that's a hassle and the quick connection is the way forward.

I also charge and recon my mates GTR which has more electrical wizardry than my w211.

 

[reflexboy]

The ctek is designed to be used with AGM batteries and this applies to the recon mode also. I have done a recon every year for the past three years with no ill effects on car or battery.

You can use jump connections but Imo that's a hassle and the quick connection is the way forward.

I also charge and recon my mates GTR which has more electrical wizardry than my w211.

Are your quick connections, connected directly to the battery, and do you have an AGM battery?

 

[Mrhanky]

Are your quick connections, connected directly to the battery, and do you have an AGM battery?

Yes sir on both counts. I have the quick connector permanently connected to the battery. It's the one with the traffic light which shows if the battery needs charging.

My main battery is a Bosch S6 AGM.

 

[190]

Thanks for the info. The recondition mode is selectable with an AGM battery, but as you suggest, I won't select that. Out of interest, why do you recommend using the jump start connections as opposed to directly connecting the CTEK to the battery posts?

In a non permanent charger connection it's safer to use the jump start points and incurs no disadvantage but if you have something permanently wired to the battery then that's fine.

While it is true that a recondition mode can be used with AGM batteries to de-sulphate them, it's a much riskier operation with an AGM because of the potential for overcharging and venting. Any generic advice would have to be don't do it unless the battery manufacturer approves the use of a specific voltage for a specific length of time. Regardless, MB would not approve of using the recon mode with the battery connected to the car.