Connecting Batteries with DIFFERENT Capacity in Parallel - What Happens?!

LiTime 48V 100Ah LiFePO4 Battery: https://www.litime.com/products/48v-1... LiTime Discount Link — Use Code MATT for 8% Off: https://www.litime.com/discount/Matt?... Can you connect two batteries of different sizes in parallel? In this video, I put that question to the test using real-world gear, real measurements, and a practical DIY solar setup. This is one of the most common questions in RV solar, off-grid power, solar sheds, and backup battery systems. Maybe you already have one battery and want to add another. Maybe one battery is older, larger, smaller, or from a different brand. The question is: when is it okay, and when is it a bad idea? In this video, we look at what happens when batteries with different capacities are connected together, how current flows between them, and what risks you need to understand before mixing battery sizes. 🔋 IN THIS VIDEO What happens when battery capacities are mismatched The risks of mixing new and old batteries How current flows between unequal batteries Why voltage matters before connecting batteries Safe wiring and best practices When mixing batteries may be okay When mixing batteries is a bad idea What to watch for in DIY solar and RV systems If you are building a battery bank for solar, RV power, an off-grid cabin, a solar shed, or backup power, this video will help you make a safer and smarter decision before connecting batteries in parallel. ⏱️ CHAPTERS 00:00 Intro - Mixing Battery Sizes 00:21 Why Mix Battery Sizes? 01:54 Mixing Battery Size Problems 05:55 Safe Ways to Mix Different Sized Batteries 08:52 Best Practices for Mixing Batteries 10:59 Recap and Review 🔧 FREE + PAID RESOURCES 🔹 Signature Solar: Discount Code MMS50 https://signaturesolar.com/?ref=jizqdwzt 🔹 Shop Solar Kits: Coupon Code MATTHEWMCINTOSH101 — $101 Off https://shopsolarkits.com/discount/MA... 🔹 LiTime: Use Code MATT for 8% Off https://www.litime.com/discount/Matt?... 🔹 Recommended Solar Equipment / Parts List: https://mattmansolar.com/start 🔹 FREE Solar Diagram: https://classes.mattmansolar.com/join... 🔹 Full Fridge Build Plan: https://mattmansolar.com/build 🔹 1-on-1 Solar Help / System Review: https://classes.mattmansolar.com/cons... 🔹 In-Home Solar Review: https://mattmansolar.com/review 📺 COMMUNITY / CONTACT Become a Member:    / @mattmansolar   Buy Me a Coffee: https://buymeacoffee.com/mattmansolar Join the Discord:   / discord   Live Stream Playlist:    • DIY Solar Live Streams   Newsletter / Bonus Content: https://mattmansolar.substack.com/?r=... Email: [email protected] 🤝 SUPPORTERS / PARTNER LINKS Bluetti EU: bluettieu.pxf.io/kObr53 Bluetti US: bluettius.sjv.io/EEVoa4 Jackery: https://jackery.sjv.io/19z9Ma Energy Monitor: https://refoss.net/?ref=Msolar 🎥 TOP RELATED VIDEOS Don’t Build a 48V Battery Bank with 12V Batteries Without This Part:    • Don't Build a 48V Battery Bank with 12v Ba...   State of Charge: LiFePO4 Battery Questions and Answers:    • State Of Charge 35 Questions and Answers L...   Build a DIY Solar Battery and Save $1000's:    • Build a DIY Solar Battery and Save $1000's   I Built a 15.5kWh DIY Battery — Way Cheaper Than You Think:    • I Built a 15.5kWh DIY Battery (Way Cheaper...   Full Off-Grid RV Solar System Setup:    • Full Off-Grid RV Solar System Setup — Pane...   🎥 RELATED PLAYLISTS Understanding Solar:    • Understand and Using Solar System Components   Solar RV Projects:    • Complete Solar System Tour in My RV: Inver...   Solar Shed Series:    • Solar Shed Panel Tuning - Setup for the Be...   💡 Some links may be affiliate links. As an Amazon Associate, I earn from qualifying purchases. Always verify voltage, chemistry, state of charge, BMS limits, wire size, fuse sizing, battery age, and manufacturer recommendations before connecting batteries together. #LiFePO4 #BatteryBank #DIYSolar #OffGridSolar #RVSolar #SolarBattery #LithiumBattery #BatteryParallel #BatteryTips #SolarStorage #48VBattery #BackupPower #MattManSolar