bulb discharger question

[tamiya4x4dryver]

If you are using a string of 10 bulbs to make a 20 amp discharger, is that discharging at a constant 20 amps from start to finish? Or, does the amperage drop more and more during the entire discharge process?

[shadowghost1]

It will be constant because all the bulbs are doing are pulling power from the battery.

[loopy]

ummm

the bulbs are a resistive load so as voltage drops so will current flow ;)

[loopy]

to get 30a from a 8.6v fully chgd pack you need .28ohm resistance.

8.6V/30a= .28 ohm.

when it is discharged (approx 6.6v) you will only be getting.......

6.6V/.28ohm = 23.5A

7A difference between fully chgd and safe cutoff V (1.1V/cell). If you were to leave them on the dischgr discharge rate should be proportional to voltage and inversely proportional to resistance until dead flat .(ohms law)

rough maths but correct enough i think?

cheers
geoff :)

[tamiya4x4dryver]

thanks for explaining that!

[Danno]

http://www.the12volt.com/ohm/page2.asp
I found this page really informative , I refer to it before I make an argument !

[highroller]

Loopy explained it better, while the bulb themselves may be rated at 2amp each, the resistance load does not remain constant throughout the discharge.

[tunnelhead]

Where can I find the MPH Products battery discharger? Cool looking one mounted in the tube with fans and battery cut off. Seen it inone ot the recent magazine. Where can you get it? Anyone have a website address for them. Havent been able to find one for them/ Thanks again!