[chbot] Have I killed my bot battery?

[Carl Ranson]

So I left my bot's electronics running on the bench overnight and my
battery is down to 7 volts (its a 12v SLA)

I've just put it on the charger and nothing happened.

The charger I have is a jaycar one (http://tinyurl.com/ytlhkx) and I
note that many of the chargers on their website have a note "These
chargers will not charge a totally flat battery".

Is it possible that 7v is low enough to make the battery non-detectable
to the charger? Is there any way to trick the charger into detecting it?

thanks team.
C