Defender 19j charging electrics

Help - my 19j 110 has suffered from a lack of charging.
I had assumed that the alternator was knackered and have been charging from a trickle charger over night to keep it usable until I can organise a replacement part.
Yesterday I ran out of charge and couldn't turn it over, luckily I was parked on a hill and bump started it. Once I lifted the clutch and turned the key there was a surge in power which allowed the starter to crank and started the car.
I've also noticed that whilst running with lights and wipers etc that they are fine, even though I couldn't get the car to start.
The battery seems to be fine and holds charge once topped up.
Is this the behaviour of a duff alternator or could it be something as simple as a power cable from the alternator to the battery becoming disconnected?
The weathers been crap here and I’ve not had the opportunity to investigate fully being late by the time I get home from work. Just wanted some opinion before I ordered a new part.
Thanks in advance for your help

is the battery actually flat - ie have you checked it with a multimetre t or is the car just not starting ?

It sounds to me that possibly something like your starter solenoids jamming.... how ever i would check all the earths and i would test for power at the starter as a starting point.

get down screwfix and get a cheapo multimeter and look on youtube for how to use it ... .will save you a heap of grief guessing....

Yeah i've checked over with a multi meter and the battery is def loosing charge after a few starts, its just that there appears to be power coming from the alternator whilst running which runs everything, but its not charging the system.

Just wondered if anybody had had a similiar issue in the past, or if it was known to occur frequently.

I think you're right about checking the earth points.

Am I right in thinking the alternator connects to the starter, the a cable goes off to the car electricial system and one goes off to the battery positive terminal?

Thanks for the reply

That's not quite how it works. (And you shouldn't be touching the key when bump starting). The battery is connected to the starter (very thick cable), and also powers all your lights etc. When the engine is running, the alternator should be putting out around 14 volts, which it sends to the battery, charging it. After starting, the battery voltage will drop a bit but should recover fairly quickly. If the alternator is charging, you should read around 13.5/14.5 volts at the battery when the engine has been running for a while. If you can see 14 volt at the battery, it's possible that the battery is losing it's ability to hold charge well. I'd swap with a known good battery to test it. If you're not seeing 14 volts, the alternator may be at fault. Also check that the earth connection to the starter/engine block.

Start with the basics. Have you checked the battery terminals and clamps for corrosion and tightness? Then check that the wire from the battery to the starter is tight at the starter end.

5 minutes with a multimeter will tell you all you need to know.
Common one is the female lucar terminal being a slack fit on the back of the alternator.