22-03-2012, 12:51 PM
BATTERY CHARGING
What does Watt Actually means ?
We Answered:
The battery is 1200 mAh, which means milli Ampere-hour.
This means it can supply 1.2 Amp for 1 solid hour at 3.7 volt.
Or 0.12 Amp for 10 hours.
How many Amp is used depends on the condition, and the actual efficiency of the battery depends on how quickly (or slowly) the charge is used.
4.4 Watt of power could charge it in one hour IF
- the charging process is 100% efficient (it is never)
- the charging is done at a voltage higher than 3.7 V (or else, the battery will try to drive the power supply, instead of being charged by it)
The actual charging time depends on the voltage applied (withing limits), and the capability of the charger to provide the required amperage at that voltage. If you have a sufficiently high (and properly suitable; you don't want to zap the battery) voltage, but a low amperage, then the battery will still charge, but a lower rate,
How much voltage is needed and how much amperage can go through the battery during recharge is dependent on the battery and phone design. Don't try to outguess the operational parameter if you don't want to risk burning off your battery and phone.
battery equalisation?
We Answered:
It depends on the individual charger, but the important part is to get the voltage high enough that your batteries equalize properly. Hook it up when your batteries are charged, and take voltage readings on the boost setting of the charger. If you can get the voltage up to about 31-32 volts, it will work.
This may damage the charger - most are not designed to put out a lot of current for very long in boost phase. Can you equalize with your charge controller? Charge the batteries overnight with your charger, then set the output voltage of your charge controller up and do it with your solar panels.