the source is 120V DC with an internal resistance of 40 Ohms. the battery's emf is 10V with an internal resistance of 1kOhms. what can i add to the circuit to improve the charging time?
Answers and Replies
Different batteries types have different charging requirements. What type are you recharging, and what is it, and from what level of discharge is it being charged from?
it's an lithium ion battery.
Lithium is very tricky to recharge. Rechargers on the market rely upon microcontrollers to quick charge, and then to top-off. Lithium batteries tend to be a fire hazard if charged too quickly or are overcharged. They sell little fire supressing bags to recharge them into keep you from burning down your house due to a mishap. They can explode in a very exothermic fireball.
1) I'm suspicous of the 1K Ohm internal resistance value you've given. It sounds way too high.
2) One wouldn't normally charge a ~10 volt battery with 120 volts. To trickle charge you would use some supply, nominally greater than 10 volts, and include a limiting resistor, and cut-off voltage control for lithium.
3) Lithium ion cells output 3.6-3.7 volts. Where does the 10 volts come from?
4) Where do you get 120 volts DC? Rectification of the 120 VAC line gives you 168 volts.
5) Why don't you purchase a charger that won't burn down your mother's house?