Good call Dave..

I would put about a 2 amp charger on it leave it over night and see if it charges up.

Put the battery on a charger to charge it right up.. If it was left for a couple of months without a battery maintainer on it the charge on it could have been very low and a 20 minute charge from the quad's system would not likely bring it to anywhere near a full charge. I just did a search on your battery and the recommended battery for your quad. Your battery is woefully inadequate for that machine. It is rated for 120 cold cranking amps and likely only 9 amp hours reserve. Specs for your quad calls for a battery with 210 CCA and 14 Ah reserve. The little battery in your scrambler might start ok when the battery is full charged and in warm weather , but in the cold it is not likely going to do well even if fully charged.