I don't know if you can do it with your charger (and there is risk involved) if you can put your charger at the minimum amount of charge amperage that is, and tell it is a NiMH battery...if you can tell the charger you have two of them, even better. You may not have a choice here......let it charge for a couple of minutes (be ready to turn off power incase something goes wrong (which it shouldn't but stay there and monitor!!)).
You might be able to "fake" the charger out that you have two NiMH batteries there, if so. Give it a couple of minutes to put some juice into the battery, then stop and try to charge it normally like you would for an Emoli (in my case with a Triton2, a LiPo).
I was very cautious when I did this with one of my big emoli batteries that died very quickly initially. You can bet after I got it to "take" the correct charge, I cycled the battery a few times. Because I didn't mark that particular battery, I don't even know which one it is......so it did recover.
YOu can do it, just be very careful. Watch your equipment, safety glasses, and all that. I do not recommend you charge your emoli battery all the time as a NiMH or maybe a couple as lead acid at 6 volts (for two of them) when the go flat. It is not good on anything and would not be recommended anywhere at anytime by anyone so just be ultra careful.....did I mention be careful? You have alot of money invested in batteries, chargers and the lot......for fun, maybe try this, if not, pitch 'em and get a couple of new ones.
Better yet, go to Tyler Tool and order a 18 volt battery pack of your own NEW, virgin Emoli's to play with. They will have some charge and will love you for freeing them from a horrible life as a power tool versus a majical life of illumination......
Bob E.