charging battery.

[Tony Dyson]

With the CTEK, Desulphation does not happen on AGM batteries as they do not suffer from this problem & is why they are ideal for deep discharge and standing unused for long periods without maintenence.

The "Desulphation" phase is an "if required" phase where the charger can detect the condition. If (as in AGM batteries) there is none, it skips to the next phase or keeps pulsing until charging can start.

About 10 years ago when I purchased my CTEK, I had several emails to and fro with CTEK. I had several (then very expensive) AGM batteries in my off road caravan (for off grid power) and my LandCruiser with an AGM auxiliary battery (also for off grid power).

The image I posted above which is from the CTEK MX5 OM clearly shows a desulphation stage taking place on every battery setting at 15.8v that can last for up to 8Hrs, you're mistaken this is not an option to deselect.

 

[rorywquin]

What specific model is your Ctek?

MXS7. Very topical as I hooked mine up again this morning. Snowflake mode = AGM mode.

 

[rorywquin]

The image I posted above which is from the CTEK MX5 OM clearly shows a desulphation stage taking place on every battery setting at 15.8v that can last for up to 8Hrs, you're mistaken this is not an option to deselect.

No Tony, you are mistaken read my post properly. I did not say it is optional deselect. I said that the charger detects if it is needed - AGM will never need it - if not needed skips to next phase..........................Mail CTEK and ask them if you are still dubious. That chart is a little misleading.

Read the first sentence of Step 1.

 

[jakewise]

I have a question, I currently have a battery charger and if I dont plan to buy a CTEK and decide only to charge my battery, what is the proper procedure of doing it? Aside from charging it slowly (not fast charge), do I need to remove the negative terminal post ?

 

[rorywquin]

I have a question, I currently have a battery charger and if I dont plan to buy a CTEK and decide only to charge my battery, what is the proper procedure of doing it? Aside from charging it slowly (not fast charge), do I need to remove the negative terminal post ?

What does your user manual say? Mine says to use the jump start points ergo, no disconnection of anything.

 

[flowrider]

The image I posted above which is from the CTEK MX5 OM clearly shows a desulphation stage taking place on every battery setting at 15.8v that can last for up to 8Hrs, you're mistaken this is not an option to deselect.

This concerned me to when I first bought a CTEK, I emailed CTEK for advice, several times as they are not very forthcoming, asking about the desulphation phase on an AGM battery and they eventually stated that the owners manual was wrong and desulphation is skipped. I had a quick look for the email but can't find it now!

My MXS 5.0 is 4 years old now so I wonder if newer owners manuals have been updated with this info.

 

[jakewise]

What does your user manual say? Mine says to use the jump start points ergo, no disconnection of anything.

Sorry, I needed to ask as I have misplaced my manual and could not find it. Can you tell me where the jump start points are located

 

[Blobcat]

Sorry, I needed to ask as I have misplaced my manual and could not find it. Can you tell me where the jump start points are located

Usually under the bonnet - +ve will most likely be under a little black plastic lid and a -ve connection will be close by - probably on a suspension strut top

 

[jakewise]

Usually under the bonnet - +ve will most likely be under a little black plastic lid and a -ve connection will be close by - probably on a suspension strut top

So positive clamp of charger will go to the little black plastic lid and negative clamp of the charger can be clamped on any negative ground? When you open that little black plastic lid under the bonnet, all the terminals thereat are all positive?

 

[Blobcat]

So positive clamp of charger will go to the little black plastic lid and negative clamp of the charger can be clamped on any nefative ground? When you open that little black plastic lid under the bonner, all the terminals thereat are all positive?

It should just have a fairly large single connection and yes that’s just +ve. Nothing else will be there

 

[jakewise]

It should just have a fairly large single connection and yes that’s just +ve. Nothing else will be there

Please correct me if I am wrong with what I understood. If I charge my battery, positive clamp of charger will be clamped under that black plastic lid under the bonnet and the negative clamp of the charger will be on any negative ground? I do not charge directly to the battery located at the trunk? Why dont we charge directly to the battery?

 

[Tony Dyson]

No Tony, you are mistaken read my post properly. I did not say it is optional deselect. I said that the charger detects if it is needed - AGM will never need it - if not needed skips to next phase..........................Mail CTEK and ask them if you are still dubious. That chart is a little misleading.

Read the first sentence of Step 1.
View attachment 64474

VRLA batteries do suffer from sulphation issues, herewith an excerpt from a popular resource, "VRLA batteries may be continually float charged at around 2.18-2.27 volts per cell at 25 °C, depending on the type and battery manufacturer specifications. An equalization charge cycle, having a higher voltage low current profile, may be occasionally utilised to partially reverse a battery sulphation condition; some SLA smart battery chargers either manually or automatically perform equalization cycles at infrequent times. Some designs can be fast charged (one hour) at high rates. Sustained charging at 2.7 V per cell will damage the cells."

Smart chargers will simply look for high resistance values of a battery to determine whether or not sulphation is an issue that needs remedy, I said in my earlier statement @ post No 19 "the initial desulphation mode is only momentary but if the charger detects any perceived desulphation and as you can see from the chart I posted earlier, desulphation at 15.8v can last for up to 8 Hrs." There can be a number of reasons for a high resistance reading of a battery and sulphation is only one of them so in the case on an MX5 smart charger it will interpret a high resistance battery reading as requiring desulphation and will invoke the desulphation stage automatically.

This concerned me to when I first bought a CTEK, I emailed CTEK for advice, several times as they are not very forthcoming, asking about the desulphation phase on an AGM battery and they eventually stated that the owners manual was wrong and desulphation is skipped. I had a quick look for the email but can't find it now!

My MXS 5.0 is 4 years old now so I wonder if newer owners manuals have been updated with this info.

I too have contacted CTEK about this issue when the subject came up before on the forum and an interesting statement from them is in stark conflict with MB OM advice with "Regarding charge voltage and desulphation:
Desulphation will only kick in if the battery is damaged with lead sulphate crystals. The crystals lead to higher inner resistance and that will trigger the desulphation mode sending pulses with high voltage and high current. Those pulses are extremly short. For that reason the 15,8 is not counted in in the charging voltage. And for that reason it is safe to use our MXS models to a lead acid battery fitted in a Mercedes.

If you are unsure - I hope you find another brand that can help you better."

I did post the full discussion on the earlier thread but that appears to be lost in the ether somewhere now? And nothing has changed in the CTEK OM my earlier post was taken fresh from the CTEK site.

 

[Blobcat]

Please correct me if I am wrong with what I understood. If I charge my battery, positive clamp of charger will be clamped under that black plastic lid under the bonnet and the negative clamp of the charger will be on any negative ground? I do not charge directly to the battery located at the trunk? Why dont we charge directly to the battery?

Because it’s difficult to get to... the terminals under the bonnet are a direct connection to the battery

 

[rorywquin]

VRLA batteries do suffer from sulphation issues, herewith an excerpt from a popular resource, "VRLA batteries may be continually float charged at around 2.18-2.27 volts per cell at 25 °C, depending on the type and battery manufacturer specifications. An equalization charge cycle, having a higher voltage low current profile, may be occasionally utilised to partially reverse a battery sulphation condition; some SLA smart battery chargers either manually or automatically perform equalization cycles at infrequent times. Some designs can be fast charged (one hour) at high rates. Sustained charging at 2.7 V per cell will damage the cells."

Smart chargers will simply look for high resistance values of a battery to determine whether or not sulphation is an issue that needs remedy, I said in my earlier statement @ post No 19 "the initial desulphation mode is only momentary but if the charger detects any perceived desulphation and as you can see from the chart I posted earlier, desulphation at 15.8v can last for up to 8 Hrs." There can be a number of reasons for a high resistance reading of a battery and sulphation is only one of them so in the case on an MX5 smart charger it will interpret a high resistance battery reading as requiring desulphation and will invoke the desulphation stage automatically.



I too have contacted CTEK about this issue when the subject came up before on the forum and an interesting statement from them is in stark conflict with MB OM advice with "Regarding charge voltage and desulphation:
Desulphation will only kick in if the battery is damaged with lead sulphate crystals. The crystals lead to higher inner resistance and that will trigger the desulphation mode sending pulses with high voltage and high current. Those pulses are extremly short. For that reason the 15,8 is not counted in in the charging voltage. And for that reason it is safe to use our MXS models to a lead acid battery fitted in a Mercedes.

If you are unsure - I hope you find another brand that can help you better."

I did post the full discussion on the earlier thread but that appears to be lost in the ether somewhere now? And nothing has changed in the CTEK OM my earlier post was taken fresh from the CTEK site.

I'm sure you are correct!

 

[jakewise]

Because it’s difficult to get to... the terminals under the bonnet are a direct connection to the battery

So aside from the difficulty factor, we can also charge directly to the battery? And no need to remove the negative terminal of the battery either?

 

[Blobcat]

So aside from the difficulty factor, we can also charge directly to the battery? And no need to remove the negative terminal of the battery either?

Correct, no need to disconnect and in reality much better not to disconnect.
Some of mine are direct to the battery and others to charging points.
I have flying leads off all of them to plug into as I’ve 4 that don’t get much use so all kept up to voltage on conditioners.

 

[jakewise]

Correct, no need to disconnect and in reality much better not to disconnect.
Some of mine are direct to the battery and others to charging points.
I have flying leads off all of them to plug into as I’ve 4 that don’t get much use so all kept up to voltage on conditioners.

Thank you very much for your reply, it surely educated me on that point

 

[DMK/Happy]

Correct, no need to disconnect and in reality much better not to disconnect.
Some of mine are direct to the battery and others to charging points.
I have flying leads off all of them to plug into as I’ve 4 that don’t get much use so all kept up to voltage on conditioners.

That is the 5 star clarification of the discussion.

 

[DMK/Happy]

Charger off,everything back,limp mode gone,,definately was the battery being down a bit,feeling good now. Thanks everyone.

 

[DMK/Happy]

Charger off,everything back,limp mode gone,,definately was the battery being down a bit,feeling good now. Thanks everyone.

Next question is,tipping sound in the middle of the dash above the android unit on start up,and on shut down with key removed, lasts a minute or so and stops,there for a few weeks now before limp mode issue, will I need a diagnostic scan?,interest appreciated.