Grid Heater Capacitor

[jwgary]

Do you think that a capacitor placed in the circuit for the grid heater might not cause the lights to dim when it cycles? I'm talking mucho capacitance like 1 Farad. Stereo shops sell these to keep stereos from dimming lights and so they have enough power. Has anyone done this? Is it really worth it? (probably not) Just a thought.

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B I G O R A N G E AMBER-FIRE (BURNT ORANGE) / BRITE SILVER 2001(. 5), 2500, SLT, Q-CAB 4x4, SWB, AUTO, 3. 55, LSD, TOWING PACKAGE
ADD-ON'S: LINE-X, 1/4" STEEL LONGHORN HITCH COVER, WESTIN NERF BARS, YELLOW-TOP OPTIMAS

 

[PRout]

No way. The reason the lights dim so much is the voltage drop when the heater starts suckin' juice. It pulls a hell of alot of current. A cap wont have the capacity to smooth that out. I do have to admit that Im not too impressed by the output of the alternator. Its rated for over 100 amps, but Ive had other ones, 60, 90, 150, that all seemed to have a better output. I dont believe its rating at all.

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2k, 30k miles, QC, SB, 4x, 6sp, 3. 54, 285/75r16 bfg/at, stock air cleaner (reliable), silencer ring "in" (runs better), Sunnybrook 28' fiver, 16,780 lbs. 18mpg (unloaded), 12-14 mpg (loaded). VA, DD1's, PS Boost module & elbow, BD brake... also, Nitrous Oxide piped direct into the block (stealth - to keep the warranty), 10 gallon per minute fuel pump, ECM right out of Don Garlit's Top Fueler (he gave it to me) (for letting him ride in my truck), Super Modified DD1 Injectors ("Hand Honed" with a 1/4" reamer & my 12v Makita). More BOMBING to come. .

 

[Patrick Hayden]

The reason a cap works with a stereo is that the current demands for the stereo are short but very strong. The cap fills in the very short time that the stereo draws lots of current. The heater grid is a long constant draw. The cap would not help this and deffintly not worth the $125-$200 for a 1 farad.

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98 12v 2500 2wd auto #5 plate "ported air box" full gauges and plenty of smoke

 

[Pete Peterson]

Its easy to check the output of the alternator at any auto electric shop. I have check my first two trucks and they held what they were rated at. The first one was a 94 with a 122 amp alternator from the factory, it load tested the 124 amp at charging voltage of 14. 1 volts. It put out 148 amp at battery voltage. I ttok it off and installed a 160 amp alternator cause my CB amp at the time was close to 2,000 watts and the heater grid pulled my big alternator down just like the factory one. That heater grid is just one great big short accross the battery terminals. I just don't start out the drive way until its through cycling, then I turn on the headlights and take off. Pete

[This message has been edited by Pete Peterson (edited 02-22-2001). ]

 

[CCahill]

Once the engine starts, and runs ,say 5 minutes... do we even need the grid heater ? Can we put in some kind of switch, or timer to limit draw. . Is this why so many trucks have a short battery life ? Just thinkin'

 

[Pete Peterson]

CCahill, good question, but I have never had the heater grid cycle that long. Normally it stops when there is a little heat in the motor. I always plug my truck in if there is a outlet handy. Pete

 

[madams]

I'm with Pete . . Usually a few mins is all thats noticable.

Anyone have the specifics as to what temp or time interval the heaters kick out?

Michael

 

[Cooker]

It funny this question was asked, because I was just thinking about this myself. What I have decided is that in theory it will work, but 1 Farad is not nearly enough. A 1 Farad cap is maybe rated for a short burst of 60 - 80 amps, and the grid heater is around 100 amps. Ok so why not 2 - 1 Farad caps? That would put us in the right range as far as reserve capacity, but as someone already pointed out, the caps are only good for a couple of seconds at most. When cold, my grid heater draws for 4 - 8 seconds at a time.

You could theoritically use caps to have enough reserve capacity to withstand the 4-8 seconds of the grid heater, but the cost would be so expensive, it's not worth the little benefit received.

As far as the grid heater operation, as designed, I think it stops operating when the intake temp reaches 59 degrees or you travel over 20 mph.

 

[PRout]

You already have 2 giant capacitors. . your batteries. Adding caps wont make a dent.

Its like pete says, that heater will be like a direct short across those caps. They will be sucked clean in milliseconds. His 2k rf amp probably pulled about 200 amps on a keydown (enough to melt 6 gauge wire) and your heater isnt too far from that. Sorry, just the truth.

[This message has been edited by Shortshift (edited 02-23-2001). ]

 

[joel]

I think the grid heaters are only supposed to cycle for 3 minutes. I could be wrong, but you don't need an on/off switch for them, just drive; when you hit 18 mph, they cut out automatically.

 

[illflem]

joel,that's how my 12 valves work,but I wait for them to stop before driving,figure the engine needs to warm a little. Some 24 valve folks have talked about their's running much more and also coming on again on a restart after the engine is warmed up. If that is the case I think I'd want a cutoff switch/relay.

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95' 25004X4,AT,Driftwood,Banks Stinger,Warn fender flairs and running boards(work truck)
95 3500,5 speed 3:54,BD E-brake,Driftwood,Banks&Psycotty,34,000 GCVW apple and tractor hauler(works harder truck)

 

[Bigramguy]

I have rewired my headlamps with relays to my aux battery mounted under the truck,with an isolator. No more flickering lights,and the lights are much brighter. This battery was originally installed for my stereo system,as the amps would get distorted when the grid heaters came on. Found it works great for the headlamps too.

I'm not sure on the specs,but I found in really cold weather,the grid heaters would cycle almost all the time,especially when the truck isn't really working very hard,or when idling at a stoplight.

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1997 2500 CC 4X4,Auto

[This message has been edited by Bigramguy (edited 02-23-2001). ]

 

[Michael Hughes]

On my 99, the grid heaters never come on after I pass 18MPH. I never thought it was that big of a deal, by the time I get to the blacktop, I have gone over 18 and they stop
cycling.

I have had them cycle if I stop somewhere and start it back up when it is real cold outside.

Do the grid heaters on the 12 value engines work different?

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1999 2500 ST LB 4X4 Metallic Red, 5-speed, 3. 54 gears, LSD, camper and tow package

 

[Cooker]

Bigramguy,
I've thought about relocating the batteries and or installing another under the bed for the same reason you did. Where exactly did you mount it, and is there enough room for 2.
Thanks,Ryan

 

[Bigramguy]

The batteries are hung off the pass side,just under the back of the cab. Made a steel angle iron frame,and used two marine battery boxes. Yes there is enough room for two. I'm thinking of moving the two front batteries back there two,because when the stockers died,I used two group 31 transport batteries (with custom trays) that weigh over 100 lbs apiece. I run very close to my FAWR with all my gear,and the 200+ lbs off the axle would help,as well as aiding traction in the rear.

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1997 2500 CC 4X4,Auto

 

[Diesel Freak]

Shortshift is right...
but it sure would be cool to have a buddy work on your truck and mistakenly discharge your cap bank with his fingers while poking around inder the hood #ad

ouch that would hurt!