Meetings/20181017
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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
- Use the highest capacity Li-Ion battery available for your radio
- When using the AA adapter
- Alkaline batteries are the worst choice. 'Use as the last resort'
- Energizer Ultimate Lithium batteries are the best choice for single-use batteries
- Extremely low self-discharge (95% of capacity after 20 years)
- Handles high current discharge
- About $1.50 per battery
- Panasonic Eneloop batteries are the best choice for rechargeable batteries
- Relatively low self-discharge (85% of charge after 1 year)
- Can be recharged up to 2100 times
- Handles high current discharge
- About $2.00 per battery
• Never charge from the radio
12V systems 20 hour ratings
- sealed / Gel
- Glass Matte
- LiFePO4 ( very good, light, field chargeable 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
- Portable Operations
- Lead acid batteries are relatively inexpensive, but the trade-off is weight, capacity, self-discharge and overall life; Only sealed lead acid batteries should be used to prevent spillage
- LiFePO4 batteries are less than half the weight of an equivalent SLA battery, has more useable capacity, can sit for long periods of time without losing much charge and has 4 times the life. The trade-off is price, but in the long-term they pay for themselves
- Home / Base Operations
- Weight is less of an issue so lead acid batteries have fewer disadvantages. Never use flooded batteries inside the house due to out-gassing. Need to keep them on a float charge when not in use
- LiFePO4 batteries will have a much longer life and will be easier to move around, but are expensive, especially for occasional use
then Rachel gave an overview of the Menlo Park CERT coms trailer.
all this is in the PDF below.
all told this was an excellent presentation