New Battery?

[lateconvert]

Read the archives and I'm 98% certain the battery's a gonner, but thought it worth checking against the combined knowledge of PH's.
Friday morning the driver's door wouldn't open, but passenger side would so I was able to get in.
No sign of the engine turning over.
Put on charge (automatic charger); it started out on 9amps. Left it for 23 hours at end of which time it wouldn't go below 2amps.
Both door locks now work, lights OK, fuel pump ticking, red warning lights off, etc, but not a sign of engine turning over.
Checked voltage at battery which is 10.5volts.
Do we think it's simply dead battery, or should I check alternator, fuse link, starter motor, anything else before I invest in a new battery?

[T88CAN]

10.5 volts should be enough for the engine to TRY and turn over, does it try at all? If not try your other options

[the dodger]

Are you de-arming the immobiliser? If the battery has gone flat the alarm has probably gone to sleep and won't de-arm on the blipper. Use the emergency plastic doo-dah. Re-set alarm by disconnecting battery for a half a minute.