Logic check please.

[PhilandMena]

I want to put 15 Volts into my cab battery (de-sulfhation charge) without causing any harm to the numerous circuits and fuses that are attached to it. My simple logic is to disconnect the negative terminal connection resulting in no earth and therefore no circuit ? Then attach my CTEK charger and charge accordingly.
Do I have it right. No guesswork please, I need a competent response to confirm or otherwise.
Thanks in advance.

 

[Jev88]

Sounds fine to me. You have broken the circuit to the habitation.
Take both terminals off for complete isolation?

 

[DBK]

You might want to check the CTEK charger negative isn't connected to the chassis. I don't think it will be but worth checking. Use a multimeter on the Ohms setting to check between the charger output negative and the negative cable detached from the battery. If there is you need to disconnect the battery positive.

 

[PhilMary]

Just a heads-up. Check you radio will still work after it is isolated before you disconnect the battery as a code may be needed.
Phil

 

[Lenny HB]

Tight arse just buy a new battery if its getting dodgy not worth the effort.
You will just have to forgo a few €1 beers.

^{_{Subscribers  do not see these advertisements}}

 

[chaser]

What's the problem with taking both terminals off, sure then.

 

[TheBig1]

By removing the ground wire, there is no circuit to back feed. Provided you use an external charger to do the desulphating of course

Make sure the ground terminal is insulated away from the terminal post and dont reconnect until at least an hour after finishing charging

 

[tonyidle]

One terminal is enough. Charger will obviously be connected only to the battery.

 

[PhilandMena]

You might want to check the CTEK charger negative isn't connected to the chassis. I don't think it will be but worth checking. Use a multimeter on the Ohms setting to check between the charger output negative and the negative cable detached from the battery. If there is you need to disconnect the battery positive.

Thanks. I don't know how to do that. I've used the charger before with the battery connected without any issues but this is the first time I will be putting 15 volts into it.

 

[PhilandMena]

By removing the ground wire, there is no circuit to back feed. Provided you use an external charger to do the desulphating of course

Make sure the ground terminal is insulated away from the terminal post and dont reconnect until at least an hour after finishing charging

Why an hour ?

^{_{Subscribers  do not see these advertisements}}

 

[PhilandMena]

One terminal is enough. Charger will obviously be connected only to the battery.

correct !

 

[PhilandMena]

What's the problem with taking both terminals off, sure then.

I'm lazy and it involves multiple connections on the positive terminal.

 

[PhilandMena]

Tight arse just buy a new battery if its getting dodgy not worth the effort.
You will just have to forgo a few €1 beers.

Up Yours! It is a new battery, well 2 year old. It's not dodgy either, just a bit of maintenance. I suppose your getting a tan now too !

 

[DBK]

Why an hour ?

The battery will retain the high voltage for a while, it needs time to recover.

 

[TheBig1]

As above, the charging voltage will remain high after you disconnect the charger, The battery may also have produced some hydrogen gas as it was charged and a spark reconnecting could ignite it

I have heard tales of airbag ECUs failing when a battery was reconnected and also when jump starting from other vehicles. An expensive fault to fix

^{_{Subscribers  do not see these advertisements}}

 

[PhilandMena]

Just a heads-up. Check you radio will still work after it is isolated before you disconnect the battery as a code may be needed.
Phil

Yes No problem with that.

 

[tonyidle]

What's the problem with taking both terminals off, sure then.

I'd take the battery into house, in a room as far as possible from the motorhome, just to be 100% certain.