Is this CTEK charger faulty?

[Paul Goff]

The constant charge voltage for lead acid batteries is 2.3Volts SMOOTH DC (No AC ripple) per cell at 20 degrees centigrade
So 13.8 VDC for a car battery. Some temperature compensation is ideal, usually 0.030VDC per cell per degree centigrade, this would be inverse to temp, so rises as temp drops.

Given the above, the battery can be left on charge permanently, it will regulate it's own current draw. A 13.8VDC regulated power supply will, if it has enough ability to supply current, charge a dead flat battery given time. A typical supply unit of say 13.8VDC and 10Amps rating will easily charge a completely flat 100 Amp Hour Battery of any type, Ignition & Lights (car), Deep Discharge, Standby, Traction etc within a day.

Intelligent automotive chargers usually, in the interest of achieving a faster charge time, have three automatic modes. The first two provide a higher voltage, typically 14.5 ish and 14.2 ish followed by a permanent trickle of 13.8. and can therefore be left connected permanently.

Is 14.7 a problem? That depends on how long it stays that high for and how much current the charger can deliver. If for no longer than a few hours after initial charge start, and/or max current rating below about 5A, then that's fine. The charger should change to the lower voltages as the battery voltage rises with the level of charge. Even if it does not, the battery will merely self regulate at a slightly higher current than ideal, this is not likely to cause any damage even for a couple of weeks!

Desulphate regimes are a different matter! Not a battery damage one, it's probably worn out anyway. These modes should NOT be automatic as they often involve pulses of voltage approaching 30V! and must therefore be carried out with the battery completely disconnected from the vehicle and ideally, removed entirely.

Of course the voltages and temperatures I am referring to are at/of the battery, the voltage displayed by the charger may not accurately reflect that!

Also the voltage presented to the battery by the vehicles own charging system is of no relevance, that is raw DC, as unsmoothed as it can be, and will easily cook the battery if unregulated! The alternator can deliver a HUGE amount of current.

 

[Arzaam]

The constant charge voltage for lead acid batteries is 2.3Volts SMOOTH DC (No AC ripple) per cell at 20 degrees centigrade
So 13.8 VDC for a car battery. Some temperature compensation is ideal, usually 0.030VDC per cell per degree centigrade, this would be inverse to temp, so rises as temp drops.

Given the above, the battery can be left on charge permanently, it will regulate it's own current draw. A 13.8VDC regulated power supply will, if it has enough ability to supply current, charge a dead flat battery given time. A typical supply unit of say 13.8VDC and 10Amps rating will easily charge a completely flat 100 Amp Hour Battery of any type, Ignition & Lights (car), Deep Discharge, Standby, Traction etc within a day.

Intelligent automotive chargers usually, in the interest of achieving a faster charge time, have three automatic modes. The first two provide a higher voltage, typically 14.5 ish and 14.2 ish followed by a permanent trickle of 13.8. and can therefore be left connected permanently.

Is 14.7 a problem? That depends on how long it stays that high for and how much current the charger can deliver. If for no longer than a few hours after initial charge start, and/or max current rating below about 5A, then that's fine. The charger should change to the lower voltages as the battery voltage rises with the level of charge. Even if it does not, the battery will merely self regulate at a slightly higher current than ideal, this is not likely to cause any damage even for a couple of weeks!

Desulphate regimes are a different matter! Not a battery damage one, it's probably worn out anyway. These modes should NOT be automatic as they often involve pulses of voltage approaching 30V! and must therefore be carried out with the battery completely disconnected from the vehicle and ideally, removed entirely.

Of course the voltages and temperatures I am referring to are at/of the battery, the voltage displayed by the charger may not accurately reflect that!

Also the voltage presented to the battery by the vehicles own charging system is of no relevance, that is raw DC, as unsmoothed as it can be, and will easily cook the battery if unregulated! The alternator can deliver a HUGE amount of current.

very interesting info, my BMW branded but CTEK made charger has a desulphate mode built in which it does for a few seconds before it starts charging, I have no control over the steps just have to choose battery type. it also came with a connector that the dealer installed in the boot and I just plug the charger into that, does that mean that desulphate mode is dangerous? as its being done with the battery still connected to the car?

 

[ajlsl600]

dont know why, ctek on eng battery never gets hot ,one on consumer does , guess its working harder, maybe telling me that that battery is on the way 0ut ?

 

[Paul Goff]

very interesting info, my BMW branded but CTEK made charger has a desulphate mode built in which it does for a few seconds before it starts charging, I have no control over the steps just have to choose battery type. it also came with a connector that the dealer installed in the boot and I just plug the charger into that, does that mean that desulphate mode is dangerous? as its being done with the battery still connected to the car?

Morning Arzaam,
I have been looking up the spec and instruction sheets for CTEK chargers and they are quite a sophisticated piece of kit!
The initial desulphate cycle is pulsed 15Volts ish, I assume that this Voltage is selected in order not to pose a risk to vehicle electronics.
The downside is that, at that low a voltage there won't be all that much desulphating going on! Not that it is going to be an issue with a battery that is healthy enough to easily start the car, and can therefore be assumed not to be sulphated.

CTEK seem to have produced chargers that cover every eventuality regarding maintenance chargers that can be left permanently connected. They are expensive though.

CTEK away my friends, all is good!