What you are describing is classic lithium battery voltage sag under load. Cold storage in an unheated garage makes internal resistance spike, so the pack looks full at rest, then the moment you pull the trigger a weak cell dips and the protection cuts output. If it happens with two packs, either both are cold or both are aging. A drill with extra drag can make it worse too. Bring a battery inside to warm up to room temp, then try the drill again. Also spin the drill with no bit for a minute and listen for roughness that would point to gearbox or chuck drag.
A simple routine helps a lot. Keep packs indoors and only pop one into the tool when you are ready to work. Give the tool a 20 to 30 second no‑load spin to gently warm the cells before driving screws. Store batteries around half charge if they will sit more than a few weeks, then top up the day you need them. Do two easy cycles to recalibrate the gauge by charging fully, resting an hour, then running the drill at low speed with light load until it stops and recharging again. Use the low gear for screws and drill pilot holes so you are not hammering the pack with big current spikes. If you can, borrow a known good warm battery from someone on the same system to confirm whether your drill is fine.
If your platform is Craftsman V20 and the packs are simply tired, a fresh higher capacity pack will hold voltage better under load and give you more working time. TURPOW V20 7.0Ah 2-pack has a larger 7.0Ah capacity and you get two packs so one can stay warm while you use the other, which directly fights that under‑load collapse you are seeing.
You nailed it on voltage sag and cold storage. Bringing the packs inside, warming them up, and giving the drill a short no load spin makes a big difference. I used to keep mine in a shed and saw the same full to one bar crash until I changed that routine and refreshed the pack. That pick fits because a healthy beefier pack holds voltage better when you pull the trigger, so the protection circuit is less likely to shut down mid screw.
Solid advice above. Two quick adds: after the charger first shows full leave the pack on it another hour so the balancer can finish equalizing cells, which helps prevent that instant under-load cutout, and try the battery on a low-draw tool from the same platform (light, fan) to see if it holds up there; if it does, the drill is the current hog. In the cold, keep a pack in your pocket or with a hand warmer and wake it with a few short, low-speed pulses rather than one long spin to gently bring the cells up to temperature.
