Second Battery not charging

[Justme]

Not neccessarily... the charging amps are far lower than the cranking amps, you can get charging amps through a partial connection.

 

Bad connections may allow a small current but not a stonking big one, especailly if its an intermittant fault.

 

I think he has replaced the batteries for new as well which dis-counts the batts

 

But thats not what he said was the problem.

 

Problem was stated as the bat was going flat/not getting charged. Not that it was charged but not providing power. If the current (and volts) has been measured to the battery & is ok then its the bat.

 

But like most problems we have not been given enough info to really get to the bottom of this.

 

If it was in front of me I would

 

chec each bats voltage at rest (12.8v is full)

chec each bats voltage under charge (up to 14.4-14.8v once nearly charged)

chec each bats voltage under load

chec the voltage at the alternator when running

chec the amps to each bat & total amps from alt

resistance test each terminal (pref under load so a Volt across the terminal test)

Then I would check the SG of the bats if poss

I would also swap the bats over if I had not found the problem yet.

 

Does it have a split charge relay/diode or are they just linked together?

If it does then test that too.

[Mike Hill]

They are just linked together.

The Batteries were tested before they were installed.I checked the voltage going into the Batteries when charging.

I think it might be the 20year old cable joining them together...

[Dean Lofthouse]

But thats not what he said was the problem.

 

Problem was stated as the bat was going flat/not getting charged. Not that it was charged but not providing power. If the current (and volts) has been measured to the battery & is ok then its the bat.

 

.

 

Sorry Justme, mis read your first line

[Justme]

No worries.

 

So when under charge what voltage are you seeing at the batts?

 

What amps are you seeing going to each batt?

 

As the batts have been changed its likely the cable is faulty but then how was the amps & volts ok?