Message Forums

Its not so much the voltage, as the current capacity, a near " flat " battery will read 12v , remember the current is the driving force , the voltage is only the conductor.

( KITSON COLLEGE , LEEDS 1973 )

If it's a "gel" type then they can be taken down to 20% of capacity. If it's a Leisure battery like the majority of us buy, then it can safely be taken down to 70% of of capacity. Why, have you left something running and now it doesn't want to hold a charge? - You norty person!

The safest way is to make a list of every electrical item that you are going to run. Add up the usage  and see how that will affect your battery capacity. BTW -  It gets even worse if you start using 12vDC to 230vAC inverters.

Got to agree there caulky

Both my Van batteries show around 13.5-13.8 volts when fully charged.

I have a battery in my garage that shows around 12.4 volts but when I connect it to the emgine of one or other of the cars, it wont even turn them over. Just a dull "Clunk"

"Both my Van batteries show around 13.5-13.8 volts when fully charged."

May I suggest that these figures will only show after a battery has been on charge . After a rest period the voltage readings will reduce to between 12 and about 12.7.

Normally 12.3 and above is adequate to start most vehicles.

HTH. 

Quote: Originally posted by EJB986 on 01/2/2008

---

"Both my Van batteries show around 13.5-13.8 volts when fully charged."

May I suggest that these figures will only show after a battery has been on charge . After a rest period the voltage readings will reduce to between 12 and about 12.7.

Normally 12.3 and above is adequate to start most vehicles.

HTH. 

---

You may suggest but you wont be 100%right

As I stated I have a batter that shows 12.4 but it wont even throw the starter over.

Volts count for nothing. Its Amps that do the hard work.