Battery Tricks and tips. Discharging and Storing your LiPo batteries Prepared and Presented By: Max Perez 905 Squadron Cub Meeting November 2014
Disclaimer: The material presented here is for information purposes only. Great care must be exercised when charging or discharging LiPos. LiPos must be handled with care. Mishandling or misuse may cause fire. Use the information here at your own risk. If in doubt, ASK!
Battery Life Battery Life; 200-400 Cycles But- Some people don t get 400 Cycles. Why? How it is charged How it is loaded when flying How it is stored
Battery Life Battery Life; 200-400 Cycles But- Some people don t get 400 Cycles. Why? How it is charged How it is loaded when flying How it is stored
Battery Cost to Operate 6S 5000 Cost $80 If abused, will only last 1 summer Assume 25 Cycles $3.20 per flight 1 Season Assume 100 Cycles 0.80c per flight Assume 200 Cycles 0.40c per flight Assume 400 Cycles 0.20c per flight 2 to 4 seasons
Storage: Target Voltage Battery ruined in one season due to storage: Voltage Too Low Voltage Too high Too Low :Batteries you flew but discharged them too much Too High :Batteries you charged but did not get to fly Storage Voltage: 3.72-3.86 Higher or lower than this will puff the pack while in storage
How to get Storage Voltage Option1: Fly in a manner that when you unplug, Voltage is 3.80 per cell Option 2: Discharge the battery to 3.80 per cell Option 3: IF below 3.72, CHARGE UP to storage voltage Use charger to charge up Charging up to storage counts as a cycle!!
Some handy tools
Some handy tools Intelligent charger
Some handy tools Intelligent charger Alarm and battery meter.
Some handy tools Intelligent charger Alarm and battery meter. Blinky for balancing
Some handy tools Intelligent charger Alarm and battery meter. Blinky for balancing Light Bulbs
Some handy tools Intelligent charger Alarm and battery meter. Blinky for balancing Light Bulbs Ammeter (Multi-Meter)
Some handy tools Intelligent charger Alarm and battery meter. Blinky for balancing Light Bulbs Ammeter (Multi-Meter) Alligator leads
Some handy tools Intelligent charger Alarm and battery meter. Blinky for balancing Light Bulbs Ammeter (Multi-Meter) Alligator leads Parallel charging board
Discharging with Intelligent Charger Discharging using :STORAGE: mode in charger Not all chargers can do this Some chargers on :STORAGE: program only charge UP, but wont discharge DOWN to storage Check to see if you charger can do this. - If not; Need to use :DISCHARGE: mode
Problems with Discharging using Intelligent Charger Problem: Wattage Resistors in charger discharge only to maximum rated wattage of resistor Mine is rated at 5.5Watts The higher the voltage to discharge, the less available discharge amps Watts= Volts x Amps Amps = Watts/Volts 6 cell pack = 5.5w / 24V = 0.2A 2 cell pack = 5.5w / 8V = 0.68A Demo Full 6 cell pack discharging at.2a to storage = 3.0A/.2 = 15 HOURS!
Discharging with bulbs A convenient way to discharge Many ways to use them Bulbs Alone Bulbs with Alarm Bulbs with Intelligent charger I like Sylvania 7443
Bulb amperage- By Elements Demo First element- Running Light 0.43A @12V Second element- Brake Light 1.81A @ 12V Both elements 2.22A @12V
2S, 3S & 4S Discharging Automotive light bulbs are rated at approx 14.7V 5S, 6S Discharging Automotive light bulbs rated at approx 14.7V 2 in series can go as high as 29.4 Demonstration in a moment-but first
Discharging with alarm Light-bulb method has one limitation- When to stop the discharge? Monitoring the volt meter is the only way Option: Use programmable alarm Set alarm voltage 3.75 Demonstration
Discharging with Boost Problems with voltage alarm: Some voltage alarms only increment in 0.1V 3.70 Alarm may be too low- Rebound too low-rebound to 3.72 3.80 Alarm may be too high- Rebound too high-rebound to 3.88 Problems with Intelligent charger on Lipo Discharge: Discharges too slow Discharge only stops at 3.0V/cell; TOO LOW If discharged to 3.0, you need to charge using storage mode-adds 1 CYCLE Solution: Discharge as NiMh and boost with light bulbs NIMH allows you to program stop voltage (alarm) Light bulbs quicken the discharge time Demonstration
Bulk Discharging Discharging 1 pack at a time Time consuming Especially if you have a lot of packs on hand Bulk discharge using Light Bulb and Alarm Method Bulk discharge using the Light Bulb Boost Method Demonstration
Questions?