De-sulphating batteries

[Gnash3]

My first post on this site I hope i have chosen the right area.

SL350 R230 2007 65K UK

The batteries are an unknown age and not OE, the health is showing 100% but the charge capacity has dropped to about 70% voltages are in the region of 12.35. Both batteries perform perfectly.

I was thinking about de-sulfating both front and back batteries before the weather starts to turn cold and the car will be stored for the winter months.

Has anybody considered this or even completed the process who may have some advice?

I do know the de-sulphate equipment will pulsate a higher voltage with a smaller current, could this be used with the consumer battery in place and connected without causing any damage to the temperamental and sensitive electronics?

Any comments or feedback would be appreciated.

 

[Germgh0st]

My CTek MXS 5.0 charger has a de-sulphate stage as part of it's battery reconditioning cycle and I use that with the battery in place.

 

[jasonh]

De-sulphating batteries on the car scares me. The voltages are too high for many ECU's - their protection circuits should be kicking in. If that happens then they'll be clamping the voltages and hindering the de-sulphation.

The technical support department of a battery charger company told me (this year) that the de-sulphation mode is low current so it should be safe on the car.

In my opinion how safe depends on the design of every electronic module on the car and not all engineers design everything fully to spec.

If I was doing it I'd leave the batteries in place but disconnect the negative from both batteries. In fact if you leave the batteries disconnected for storage then they'll be good for 6 months, as opposed to 6 weeks connected to the car, before they need a recharge.

 

[190]

Owners manuals generally stipulate a maximum safe charging voltage. Mine says 14.8 volts. Anything above that and the battery needs to be disconnected. Desulphation voltages are typically be in the region of 16 volts so I would disconnect it without question.

 

[ALFAitalia]

12.35v is only about 70% charged.....so it needs a good charge before you can really tell anything. Personally I don't think de sulphating does anything long term.....if its sulphated its reached the end of it life and need replacing. If it does not hold about 12.6 V an hour or two after charging its had it anyway. If it was regularly charged and kept at the correct voltage it should not sulphate in the first place.

 

[Bobby Dazzler]

My first post on this site I hope i have chosen the right area.

SL350 R230 2007 65K UK

The batteries are an unknown age and not OE, the health is showing 100% but the charge capacity has dropped to about 70% voltages are in the region of 12.35. Both batteries perform perfectly.

I was thinking about de-sulfating both front and back batteries before the weather starts to turn cold and the car will be stored for the winter months.

Has anybody considered this or even completed the process who may have some advice?

I do know the de-sulphate equipment will pulsate a higher voltage with a smaller current, could this be used with the consumer battery in place and connected without causing any damage to the temperamental and sensitive electronics?

Any comments or feedback would be appreciated.

Just make sure that it’s not an AGM battery as it will damage the battery. CTEK state that AGM’s shouldn’t be desulphated but still allow you to select that portion on the charger.

 

[Will]

The batteries are an unknown age and not OE

If it were mine and I was keeping it a while, I think I’d consider new batteries.

Quite a lot of sensitive electronics on an SL, sub-par batteries can cause a myriad of issues. Wouldn’t recommended de-sulfating them, I would just replace them with OE ones.