Meetings/20181017

HMB Radio Club

Rachael Kiroshita, an engineer from Menlo park ( KK6DAC ) has spent the last few years working on battery supplies for emergency situations. This has involved a lot of field testing and experimentation. In this meeting ( open to all ) she presented her findings )

Batteries

• Alkaline - Long Shelf Life. Not good for many radios due to the radio's high current requirements. May leak, damaging equipment
• NiMh - Much better. examples: Enerloop / Tenergy. Good energy density. don't leak nice constant discharge over time, slightly lower voltage.
• Primary Lithium - Very Very long shelf life. Don't leak. These are not rechargable. Those are Lithium Ion.
• Lithium Ion - pretty good will run 9 hrs in testing until there is a voltage drop off. With months charged on a shelf they will lose very little power.
• Regular AA batteries - only as a list resort

solar panels - "Powerfilm" have worked the best in her testing

with BaoFengs

• with standard battery pack 6 hours
• extended pack 12 hours
• AA compatible battery pack
  • regular akaline batteries 50 min
  • Lithium Primary batteries 13 hours
  • enerloop batteries 6 hours

AA format chargers - xtar dragon Vp4, Nite Core d4, Maha

12V systems 20 hour ratings

• sealed / Gel
• Glass Matte
• LiFePO4 ( very good, light, field chargable with proper charger )

use a state of charge monitoring charger to avoid damage to battery

Lead / Sealed / Gel @ 50 watts: 4.5 hours 25W 7:45 hours LiFeP0 @ 50W: 6:15 hrs, 25W 9hrs