Turning my PC LITE from IKELITE into a "canister light"

[champ]

I understand the value of having a super bright light on a dive. I have only seen really bright lights in "canister" form. My question is if anyone has just tried a brighter bulb in their standard dive light. I currently use a PC LITE from IKELITE. It has a 7.5 watt, 5 volt halogen bulb and uses 4 C cell batteries. What would happen if I just replaced it with a 25 watt bulb and used 4 NiMH batteries with 4500 mAh each? I think it would give me enough batterie life.

Has anyone tried this? Where did you buy your bulbs? How did it work?

 

[jonnythan]

champ once bubbled...
I understand the value of having a super bright light on a dive. I have only seen really bright lights in "canister" form. My question is if anyone has just tried a brighter bulb in their standard dive light. I currently use a PC LITE from IKELITE. It has a 7.5 watt, 5 volt halogen bulb and uses 4 C cell batteries. What would happen if I just replaced it with a 25 watt bulb and used 4 NiMH batteries with 4500 mAh each? I think it would give me enough batterie life.

Has anyone tried this? Where did you buy your bulbs? How did it work?

You'll only get 4.8 watts out of the 4 NiMH batteries.

What's the voltage for the 25 watt bulb? Chances are it will just be very dim, if it will emit any light at all. You'd probably need 10 cells to get 12 volts which is what the 25 watt bulb is probably rated for.

 

[jtivat]

Go to this site and ask your questions in the MOD section they will give you info on upgrading just about any light.http://www.candlepowerforums.com//ubbthreads/ubbthreads.php?Cat=

 

[champ]

Jonnythan,

A standard C cell battery starts with 1.5 volts but it degrads rapidly (picture a straight line starting at 1.5 volts going to 0 volts over time). A rechargable NiMH battery starts at 1.2 volts but it does not start degrading until the end of it's life (picture a horizontal line that drops straight down after it's life is up). I would need to find a 4 or 5 volt 25 watt bulb. My math on battery life is as follows ... 4.5 (Ah/battery) * 4 (battery) * 5 (volts) / 25 (A * volts) = 3.6 hours.

Thanks for your thoughts,

Champ

 

[jonnythan]

champ once bubbled...
Jonnythan,

A standard C cell battery starts with 1.5 volts but it degrads rapidly (picture a straight line starting at 1.5 volts going to 0 volts over time). A rechargable NiMH battery starts at 1.2 volts but it does not start degrading until the end of it's life (picture a horizontal line that drops straight down after it's life is up). I would need to find a 4 or 5 volt 25 watt bulb. My math on battery life is as follows ... 4.5 (Ah/battery) * 4 (battery) * 5 (volts) / 25 (A * volts) = 3.6 hours.

Thanks for your thoughts,

Champ

The math doesn't quite work that way. You only get 4.5 amp hours at 1.2 volts per battery.. since you're going to be at 4.8 volts, you only get 4.5 amps total (since the batteries are in serial)

Therefore, you're looking at 4.5 Ah * 5 volts / 25 VA = 0.9 hours.

Also, good luck finding a 5 volt 25 watt bulb..

 

[Charlie99]

champ once bubbled...
My math on battery life is as follows ... 4.5 (Ah/battery) * 4 (battery) * 5 (volts) / 25 (A * volts) = 3.6 hours.

Not quite right. 25 watt bulb from a 4 cell (approx 5V) battery draws 5A (5A*5V=25W). The 4 batteries are in series, to 4.5Ah/5A = 55 minutes.

Or another way to calculate is to realize that each battery has 1.25V*4.5Ah= 5.6Watt-hours of energy, therefore the 4 cell pack has 22-1/2 Watt hour capability.

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Aside from low battery life, the head probably isn't designed to dissipate 25 watts of heat.