I'm having a problem determining resistor specs (especially wattage) for my voltage divider circuit [ 27 V to 17.5 \$+-\$ 0.5 V ] on 10 ampere DC supply.
I have an AC (220V 50Hz) to DC (27V 10A) power supply which I want to use to charge a (14.8V nominal) Li-ion battery. Any voltage above 16.8V (full charged) will do, as long as it's not too high. (Should I even consider using 27V directly?)
I have 5 each of [1 Ohm,10 Watt] and [2 Ohm,20 Watt] resistors lying around, can they be used in some combination?
Any suggestions on how can it be done, any inexpensive alternatives?