MX3

hi
i'm building a bulb discharger...how many bulbs do i need to make a 20 or 30 amp discharger....bulb specs are 12v 25w(i knoe i have to use #1157 but there no number to this bulb that i bought)......does it draw more amp when using with a 7.2v than a 4.8v pack??anyone please help me...i'm not electrically inclined so i dont know what to use for my 7.2v and my 4.8 vpack ....thanks all for looking and replying

blueboy

If your racing stock motors then you need to discharge at 20 amps; that's 10 blulbs.
If you race modified then you should discharge at 30 amps; so you need 15 bulbs.

David Root

I used 3157 bulbs. They have 2 filaments, and are the newer 1157. They have wires you can bend out. I bent out all thewires there are 2 on each side. Bend them so they stick perpendicular to the bulb. I them put the bulbs in a circle. They just fit. Solder all the wires on one side and all the wires on the other side. Hook a heavy wire to each group of wires. It comes out to 10 amps.

Each bulb should look like thisl _0_

Works great, no jig needed or holder when it is finished.

I paid $7.00 for the box of bulbs.

My packs are performing much better since I started using this.

David Root

daniz24

I heard that Bulbs are not good for NiMH...

Jack Smash

iTrader: (35)

Just remove the bulbs from the battery before they fully go out for NIMH packs.

rctc3

about 10

marvi

iTrader: (82)

i suggest installing a battery cutoff device (i use a deans black box 2) to prevent over-discharging your batteries. i have a homemade discharger with 10 pcs 12v automotive bulbs, plus the black box.