By York R/C Club
Introduction
Colder air means longer throttle-on times and stressed batteries. A LiPo stored at the wrong voltage or temperature will puff, self-discharge, or lose punch by spring. This guide shows the exact voltage, temperature, and routine that keep packs healthy all winter.
TL;DR — Balance-charge to 3.80 V/cell, store packs between 45 °F and 70 °F, check voltage monthly, and log internal resistance. That’s 90 % of winter LiPo care.
1 — Why Autumn LiPo Care Matters
- Cold, dense air demands longer throttle—stressed packs can swell in flight.
- Li-ion chemistry ages faster outside 40–90 °F; details in Battery University: What Causes Li-ion to Die?
- Storing fully charged packs plates lithium and steals capacity.
2 — Pre-Storage Checklist
| Task | How-to | Goal |
|---|---|---|
| Balance charge | Use storage mode or stop at 3.80 ± 0.02 V/cell. | Prevents lithium plating. |
| IR log | Record mΩ/cell with the ProgressiveRC LiPo IR tool. | Spot aging cells early. |
| Visual & smell test | Check for swelling, pinholes, vinegar odor. | Discard unsafe packs. |
| Label date & capacity | Blue tape + Sharpie on balance lead. | Know when it was stored. |
| Connector wipe | De-ox spray or 91 % alcohol on XT60/EC5 pins. | Stop winter corrosion. |
3 — Choosing a Storage Environment
| Option | Pros | Cons | Notes |
|---|---|---|---|
| Indoor closet (60–70 °F) | Steady temp | Takes space | Best if housemates agree. |
| Fire-safe box in basement (50–60 °F) | Extra fire barrier | Higher humidity | Add silica gel, vent monthly. |
| Insulated garage cabinet (45–55 °F) | No indoor clutter | Temp swings | Use a USB temp logger; keep off concrete. |
Never store packs directly on a concrete floor—moisture and temp swings ruin shrink-wrap and leads.
4 — During-Storage Maintenance
- Monthly voltage spot-check; top any cell below 3.70 V back to 3.80 V.
- Swap desiccant packs when indicator dots turn pink.
- Re-test internal resistance in January—retire any pack up > 10 mΩ.
- Rotate packs 180° in the box monthly to distribute electrolyte.
- See practical tips in Flite Test: LiPo Safety.
5 — Optional Winter Upgrades
| Upgrade | Benefit | Cost |
|---|---|---|
| 12 V heating pad (100 °F) | Pre-warms packs at field | $18 |
| Cellog 8 monitor on box lid | One-touch pack scan | $12 |
| Silicone balance-lead caps | Stop oxidation | $6 / 10 pcs |
Already worked through your Fall Flying Checklist? These upgrades pair perfectly with that routine.
6 — Spring Wake-Up Procedure
- Bring packs indoors 24 h before first charge; let condensation evaporate.
- Balance-charge to full at 1 C, then storage-charge once to wake chemistry.
- Compare IR to autumn log; any cell > 35 mΩ or Δ > 40 % → trainer duty or disposal.
- Flight-test with gentle circuits before high-amp 3D punch-outs.
7 — FAQ Quick-Hits
Can I store LiPos in a fridge? Only if it stays above 40 °F and packs are double-bagged with desiccant—condensation is the enemy.
Is 3.85 V/cell better than 3.80 V? Either is fine; consistency matters more than the exact number.
Do LiPos self-discharge like NiMH? Much slower, but extremes of cold or heat accelerate it—hence monthly checks.
Graphene LiPos? Treat the same; IR rises more slowly, but over-voltage storage still plates lithium.
Conclusion
Treat your LiPos with the same respect you give your airframe and radio gear: correct voltage, clean connectors, steady temps. Follow this autumn routine and your packs will greet spring at full capacity and low internal resistance.
Happy flying! — York R/C Club
Published October 24 2025
Internal links: Field Repairs • Fall Flying Checklist
External (no-follow): Battery University • Flite Test LiPo Safety