5V @ 50A = 250 watts of heat (that's like 4 60 watts light bulbs!!). Your current shunt will be wasting a LOT of power.Thanks for the reply. I forgot to mention that i need exactly 0.1 ohm shunt for 5V drop @50A. The shunts for ammeter has a very low resistance like 0.005 and like that. So if i m going to use ammeter shunt then i have to put a cut in it until it become 0.1 ohms. also i have heard that if shunt temperature goes above 150 degrees then its resistance changes permanently. so by putting a cut in it will increase the resistance but will it increase its temperature? i think the gauge at that cut will obviously be low but also temperature at that point will be high also.
You can use 0.1 ohm resistors, IF...Thanks for the reply but i m not building a heater. I m building a big battery charger. I m fast charging SLA batteries. Some people here are still sticking with old concepts of battery charging but there are new fast charging algorithms on the web now. previously i made 12 amp ,3 stage charger and i experimented it on a 12 Ah battery for 6 months. battery is still healthy. Now i need shunt to have precise amount of constants current that is why i can't use those golden type 0.1ohm resistors.
Have a look here and u will understand. and comment there for my solution. thanks for your time.