CTEK D250SA Issue

[Rosco1200]

Following on from my previous post please see the two plots of the CTEK D250SA output as monitored on the CTEK Battery Sense connected to the new AGM battery, does anyone have idea why the Voltage appears to be rising to 15volts before dropping back to 14v then 13v, I understood that the maximum output in AGM mode should be 14.7volts. Does it suggest a fault on the D250SA output, do you think 15v will damage the new AGM battery?
Appreciate any help or advice!

 

[t0mb0]

View attachment 317370View attachment 317371

Following on from my previous post please see the two plots of the CTEK D250SA output as monitored on the CTEK Battery Sense connected to the new AGM battery, does anyone have idea why the Voltage appears to be rising to 15volts before dropping back to 14v then 13v, I understood that the maximum output in AGM mode should be 14.7volts. Does it suggest a fault on the D250SA output, do you think 15v will damage the new AGM battery?
Appreciate any help or advice!

It’s a bit hard to see the exact voltages on that plot but the most likely explanation is the temperature compensation if your device has a temperature probe? Mine is also running 14.7v nominal but I can see it getting towards 15v when the battery is relatively cool.

 

[t0mb0]

To elaborate on the above, according to the CTEK 250SA manual the temperature compensation is 23mV per 1°C away from 25°C. Therefore, if the temperature is 15°C then you can expect a charging voltage compensation of 0.23V so you're up to 14.93V already if you've specified 14.7V nominal. I would imagine this caps out in reality rather than keeping on going so maybe it caps out at 15V?

Does this make sense, was it relatively cold when it was charging? And is your temperature sensor correctly attached to your battery?

 

[Rosco1200]

To elaborate on the above, according to the CTEK 250SA manual the temperature compensation is 23mV per 1°C away from 25°C. Therefore, if the temperature is 15°C then you can expect a charging voltage compensation of 0.23V so you're up to 14.93V already if you've specified 14.7V nominal. I would imagine this caps out in reality rather than keeping on going so maybe it caps out at 15V?

Does this make sense, was it relatively cold when it was charging? And is your temperature sensor correctly attached to your battery?

Thanks for your reply, the readings were taken over the past two days, yesterday around 8deg, today nearer 12deg. The voltages were also measured with a multimeter that correlated with the CTEK Battery Sense display and yes the battery temperature sensor is attached to the leisure battery. As you say maybe the voltage is up because of lower temperatures. More other thought/concern was whether any damage was done to the D250SA output when charging the previously dead AGM battery before I swapped it?

 

[t0mb0]

Thanks for your reply, the readings were taken over the past two days, yesterday around 8deg, today nearer 12deg. The voltages were also measured with a multimeter that correlated with the CTEK Battery Sense display and yes the battery temperature sensor is attached to the leisure battery. As you say maybe the voltage is up because of lower temperatures. More other thought/concern was whether any damage was done to the D250SA output when charging the previously dead AGM battery before I swapped it?

It’s unlikely a duff battery damaged the CTEK and it appears to be operating within its stated parameters with respect to the temperature compensation. You could always contact CTEK though if you want some reassurance.

 

[Dellmassive]

Looks fine to me.