Apollo glider resurrected- battery question

Looking to trying a spot of thermal flat field in the summer , possibly entering a comp or two.
I've found a Pete Kessel Apollo glider which has. Multiplex 600 motor. The battery used was a 7 cell ( 2/3 sc )) in line 1200 nicd about 6 inches long.
I was wondering if a 2S lipo would be a suitable battery, when I came across on HK an "airsoft" battery about the same shape which it says is a 2S lipo. Apparently it is used in some sort of gun!
Would this airsoft battery work as an ordinary 2S lipo and would it be suitable for use in the Apollo...?
It is cheap enough to try out, but I didn't want to get something that might be unsafe.

Knowledgeable advice appreciated
Thanks

Hi, Dave.

You should contact Chris Hague about this. He runs the 600RES activities, for which the Apollo was designed. You can reach him on 07967 three oh six 201.

Dave - I have no experience running a Ni-mH ESC from a Lipo but suspect you would need to be able to reconfigure the ESC to recognise Lipo voltages. Otherwise it will not provide electric motor cut to protect the BEC power to your radio.
If you have selected Airsoft batteries because the size suits your model, provides the capacity and discharge rate you need - i see no reason why you could not use them -

Thank you Phil and Kevin.
I spoke to Chris who was helpful. However he hasn't used lipo with that motor.
Further research on the esc shows it cannot be configured for lipo. I'll get a nimh battery and go from there. I may in future change motor, esc and use lipo, if I think it's worth it.
HK seem short on 8.4 nimh batteries , and component shop isn't a lot better, I can get a 1600 but 1200 seem rarer than hens teeth
Anyway, thanks again for your assistance

Do not get a NiMH.

I'm just heading out but will be back in touch later this morning with better advice.

If it were me I'd buy a 2 cell lipo that weighs about the same as the 7 cell NiMH it's replacing. Look at the zippy compact range from Hobbyking.. I'm in my phone now so cannot easily look for you. A 2 cell lipo is going to be as cheap or maybe cheaper than a NIMH. It will also have so much extra capacity that you'll never reach a low voltage cutoff. As such, the existing ESC will be fine.
At a later date you would probably want to replace the heavy and inefficient brushed motor (and controller). This is also a cheap fix.
There is someone in the WSA flying an Apollo but I can't remember who. He would be able to advise on motor and ESC but get yourself up and running with a 2 cell battery first