Battery Boost Circuits

(This is a thread of my messenger many years ago – you will be able to notice text communication is quite difficult. sometimes even verbal expression will not specify the need, We need clear drawings and specs)

Sam: I was going thrugh some IC like MAX8880/MAX8881, can u help me with using that with input from my batteries?

dapj: let me see

Sam: It’s datasheet says that Supply current [Iin] = 10uA max does it mean it will draw a max of 10uA from my battery?

dapj: it looks like it will work from 2.5 to 12V and it can give you a 5v out 200ma

Sam: Exactly!

dapj: is 5V enough 200mA too, but it cannot boost voltage

Sam: my concern is with my input. What about using rechargeable batteries [4×1, 2100mAh] to act as input to this IC. will it consume 10uA if I do so while my load to the output may vary from 100mA to 200uA

dapj: if you want 5V you need to feed this atleast 5.5V this chip does not consume anything (the uA is Standby consumption )but it is not a voltage doublet or a charge pump

Sam: OK, I need to feed it anything between 5.5 -12V, Do we get recharge battery near about 2V, 2100mA

dapj – a 12 v battery can be recharged when 11.8V is reached it may charge upto 12.8 V in Li ion

Fast, smart NiCD/NiMh battery charger – The MAX713 is designed for NiCd batteries, while the 712 is for NiMh batteries.