OK. What just happened here?
 

Good morning team.

I replaced the battery on the old girl last week (she's a 2 phase SP, if it makes a difference). I took her out for a spin yesterday evening and after I got back home she refused to re-start to go back in the garage. No pump priming noise and the relays were clicking away madly. Checked the battery, and it was only reading 7v.

Charged it up last night.

Tried it this morning; pump primed as normal, pressed the start button and got an almighty flash off the -tive terminal of the battery!! Nothing's loose. Haven't tried to start it again - although I tried the ignition again and the pump is still primimg fine and all the electrics are all still working.

Any ideas?

Thanks.

I would suggest that even though it would appear that the battery terminals are tight it sounds as if you have a poor quality connection on at least the positive.

It will low small amounts of power to the pump, but breaks down when you put the big load of the starter on it.

The same problem may well cause charging problems.

Chris

Sounds like it's not charging for a start, so the usual - charging fuse could be blown/dirty/corroded or the reg/rec is knackered (you should get around 14.5 volts across the battery terminals when the engine is running - some say around 3K revs but I get that even at idle).

Assuming all you contacts are tight, there is nothing to say that they might not be dirty/corroded and are arcing. It might not be the positive battery terminal either, I reckon it's more likely to be the starter solenoid arcing...again regular suspect for the dirty and corroded arcing syndrome.

If all you charging circuit checks out OK (including a check for burnt connectors and blackened wires) it could just be that the battery is knackered and isn't holding it's charge

OK guys - Thanks for your words, and now for an update:

The battery is 5 days old so I don't immediately suspect it, but perhaps it's just not a good un'.

The flash def came from the neg terminal (my face was only about 12 inches away from it at the time and I nearly pooped myself) - and it also left a grey sooty deposit around the terminal.

I've cleaned up both terminals with a bit of 320 grade and tried re-starting it again....

Success!!! She fired up as normal and I took a reading of 14.4v across the terminals @ 3000rpm so she appears to be charging fine.

As the only thing I did was clean the battery terminals it must have been that - but as I said before, it's a spanking new battery (unless, do Yuasa coat their terminals with something to protect them during storage? The last battery I bought was a Varta).