Getting a completely dead battery started again can be a bit tricky. We've updated our charging methods over the years, but your unit has very old firmware on it, so it's not using the newer methods.
If you still want to try, plug the battery back in to the D10A. Power up the D10A on pins 1&3 for about 2 minutes. Pull the power to the unit. Then plug it back in for about 2 minutes. Repeat this a few times. This should get the battery back in action. You'll then need to keep it plugged in and on for a day.
Your other option is to build up a harness to update the firmware in the unit.
You can tell if the battery is charging by bringing up the VMETER info item. This will have an "I" voltage, which is the internal battery. If this starts reading something besides 0, we've detected the battery and are charging it. It's totally dead at about 14V and charged at 16V.
As a note to you and other customers, please don't ever try and charge the battery yourself. It's a Lithium-Ion battery, and you can't just hook a voltage up to it to charge it. You need a complex mix of current and voltage control to do it properly. The battery does have a self-protection circuit built in to prevent abuse or any big problems, so it's not a huge deal, but just hooking 12V to it won't do anything, especially since the battery needs 16.8V to charge.
If all else fails, you can always mail us the battery and we can test it and charge it for you.