You can use married batteries in another mod that uses married batteries. Just keep the twosome or threesome together.
If batteries are not "married", they will drain and age at different rates, causing one to become inferior to the other(s). The weakest battery is much more prone to be vulnerable to go into thermal runaway when stressed. The goal to "marrying batteries" is to allow them to age equally and at the same rate.
As a battery "ages", it's mAh capacity drops. As the capacity drops, so does the battery's C rating (amp limit). So eventually, your 20 amp battery becomes a 10 amp battery. You wouldn't want to use a 10 amp battery with a 20 amp battery in a two-battery mod. Get what I'm saying?
Why can't you use them in another mod? I use my married batteries in a bunch of different devices.