11.9 volts

MikkiJayne · #1 3rd July 2019, 12:07 PM

It sounds like something is eating a lot of power when it shouldn't be then. The battery terminals certainly should not be warm. Is the terminal itself connected ok? A bad connection to the battery post could cause a resistance which then generates heat. Its quite common for people to over-tighten the terminals which crushes them, then they can't seat on the battery post properly. Is the top of the terminal flush or below the top of the battery post?

Have you had a look in the access panel above the battery to see if the main fuse is also getting warm?

johnny_quattro · #2 3rd July 2019, 01:56 PM

Quote:

Originally Posted by MikkiJayne

It sounds like something is eating a lot of power when it shouldn't be then. The battery terminals certainly should not be warm. Is the terminal itself connected ok? A bad connection to the battery post could cause a resistance which then generates heat. Its quite common for people to over-tighten the terminals which crushes them, then they can't seat on the battery post properly. Is the top of the terminal flush or below the top of the battery post?

Have you had a look in the access panel above the battery to see if the main fuse is also getting warm?

I'm going to check the car shortly for its daily starter test. Terminal connectors are on solidly with no movement. I'm fairly sure (from memory) that the terminals are both level with the battery posts. Will check the main fuse as suggested. Thanks, MJ.

johnny_quattro · #3 3rd July 2019, 06:20 PM

It's the simple things in life that count.

Battery terminals were level with the top of the battery posts but the voltage was still low with the engine running. My positive battery terminal (and the post) were warming up rather nicely which proved in my non-electrician's mind that there was some resistance causing the problem. I went to the effort of checking for parasitic drain whilst I was there, even though that wasn't the root cause of the problem. Nothing out of the ordinary when I checked the mA draw on the multimeter.

Took both terminals off the battery and inspected the battery posts. I noticed that there was a vertical ridge on both terminals which you could feel with your finger, let alone a nail. I suspect that this may have been down to the local grease monkey over-tightening the terminal - this may have been due to the work done where the local garage replaced my fuel pump recently. I managed to remove the ridge that was present on both posts and then applied some copper grease to the terminals.

End result - was able to start the car without my jump pack for the first time in a week or so. I checked the voltage and was now seeing 13.6V with the amp/stereo pounding away. Checked the posts after 10-15 mins of idling, and both terminals were 'cold'. I've just been on a good run in the car, with some spirited driving as they say. Famous last words and all that, but I think it's now sorted. Motto of the story - always double-check connections even if the terminal connections appear to be well secured to the battery posts.

ainarssems · #4 3rd July 2019, 08:08 PM

Glad to hear it's sorted but copper grease on battery terminals, first time I hear it. I normally file battery terminals and cable clamp inside shiny, attach and then apply general or anti corrosion grease on the outside after assembly.

johnny_quattro · #5 4th July 2019, 09:42 AM

Quote:

Originally Posted by ainarssems

Glad to hear it's sorted but copper grease on battery terminals, first time I hear it. I normally file battery terminals and cable clamp inside shiny, attach and then apply general or anti corrosion grease on the outside after assembly.

My tube of copper grease must be about 20-25 years old now, only about half the size of a tube of toothpaste so therefore used sparingly but with great effect.

tc4332 · #6 7th July 2019, 07:01 PM

I was taught to use Vaseline.
I keep a special "garage use only" pot in the garage.
Of course I also use it when messing with water hose connectors.

johnny_quattro · #7 13th July 2019, 09:52 AM

I started to have problems again where I'd left the car overnight and it would start up fine, but if I drove the car and left it for 10 minutes, it was flat as a pancake and only hinted at turning the engine for 1/4 of a second before the click of death from the starter motor solenoid. An auto electrician was employed and the subsequent load test of the battery (after being left on charge overnight) showed almost complete failure - 300 amp load was placed on the battery but before it had got to 180-200 amps, the voltage was showing as low as 8.4V-8.5V. Battery was therefore toast and a letter on headed-paper was given to me so that I could go and get a refund from Harry Halfords.

The auto-electricians involved mentioned that they had dealt with a fair few customers over the last year or so that had had issues with starting their cars and a high percentage of them were Yuasa Silver. Suffice to say, Johnny G now has a Bosch battery.