Batt Q: 200A fuse survives on "+" terminal so starter draws <200A?

[crazypete]

Hi folks!

To make the story short....been looking at getting into racing with this thing and the ihra trunk mounted battery rules make my brain hurt.

They want a sealed battery box (extra $50) with jbolts welded or bolted through floorpan = 2 holes and a remote disconnect switch = 1 more hole and funky lever out the back (holes, $$$ and pita). I hate the very thought of drilling holes in my car.

Well, I just finished reading some thread where some guy used a magna motorcycle battery rated at 180 CCA to start his car. What a great idea I thought. Take my 30 pound battery and about 5 pounds of battery cable running to the trunk out and stick a 10 pound battery back in the enginebay and be done with it.

So I got to thinking...if my 200 amp fuse survives during cranking.....I cannot be drawing more than 200 amps. Hence...anything with more than 200 CCA's should suffice...right?

Now before someone says hawker/odessy , yes they are nice but they are generally 13-15 pounds and $90-100 or so and the dimensions of a hawker 16ep are 7.15 x 3.01 x 6.61 at 13.5 pounds and a magna motorcycle battery is 6 x 3.5 x 5 1/8 at 9.5 pounds and is $40-50....much better priced for a quick experiment, much easier to place.

What do you all think? Am I right with my 200 amp fuse assessment?

Thanks for looking!

Pete

 

[jrichker]

The stock wiring does not include a fuse in the starter circuit. Why did you add one?

As far a current draw, there are ammeters designed to measure the starter current draw. They slide over the wire and don't require any direct elecrical contact. The magnetic field that surrounds an energized starter wire makes them work.

 

[crazypete]

The stock wiring does not include a fuse in the starter circuit. Why did you add one?

As far a current draw, there are ammeters designed to measure the starter current draw. They slide over the wire and don't require any direct elecrical contact. The magnetic field that surrounds an energized starter wire makes them work.

The "fuse" in question is a 200 amp 12 volt automotive "audio" circuit breaker used by some crazy people who run 200 amps worth of stereo equiptment

It was installed as a "reusable fuse" (as opposed to the $40 ceramic ones) for my existing trunkmount battery as a precaution against chassis grounding of the "+" cable.

I am figuring since it has never blown that my hi torque mini starter is pulling less than the circuit breakers rating.

It's one of these:

http://www.cardomain.com/item/LITCB200

Though not that exact brand.

 

[Daggar]

A normal (non hi torque) starter for a Ford small block in good shape will draw roughly 60 amps. It could be as much as 100 amps on a high compression motor. Hi torque starters tend to draw a bit more.

 

[crazypete]

A normal (non hi torque) starter for a Ford small block in good shape will draw roughly 60 amps. It could be as much as 100 amps on a high compression motor. Hi torque starters tend to draw a bit more.

So now I'm confused as to why most factory cars are equipped with these gigantic batteries rated at 500-600 CCA's when the starter draws only 60-100 amps.

Why wouldn't I be able to use, for instance, a mini "lawnmower" or motorcycle battery rated at 200 amps to start the car?

I mean, after that, the alternator takes over anyway and the battery is used primarily to stabilize voltage.

why the big battery in the first place?

 

[Daggar]

The CCA rating on the battery is just one small portion of the electrical supply needs for a car.

The battery's ability to provide a continuous supply of steady power for all the little lights and gismos is also essential. Take for instance, the current draw of a fully loaded GT when the car is off and just sitting in the garage. The EEC stays alive, your radio settings, and a few other odds and ends that don't jump right into memory as I type this.

Your battery is also a HUGE part of voltage regulation for the entire car. Alternators are not rocket science and are not delecate pieces of finely tuned technology either. Voltage spikes, lows, highs, varying out put dependant upon RPM, condition, and even environment can effect their output. The battery takes on the chore of leveling that whole thing out to what is tolerable for the electrical system.

A motor cycle battery on said fully loaded GT for instance, might show some pretty big signs that it's not up the task. Just stepping on the brake and watching lights dim, or switching on the turn signal and watching your dash panel dim and get bright in unison with the blinker, would all be signs that it doesn't have the capacity to regulate the electrical demands that are being put onto it regardless of the output ability of the alternator.

For a race only application, I think it's a great idea! Then again, there arent nearly as many electrical demands and changes as there would be in a full dress street car. Nor would there be the same constant changes in supply and demand on the electrical system when you're running just quarter mile at a time at WOT.

 

[crazypete]

Well, I am running a carbureted car so no EEC, electric fuel pump, electric fan.

I still have a full complement of lights, wipers, horn and a decent stereo system with amp but the entire car is routed through 4- 30 amp fuses (no fusebox, I rewired it a while ago) so I cannot be drawing all that much juice.

So lets say I go to autozone tongiht and grab me a motorcycle battery, hook it up, start the car, hit the lights, wipers, turn up the stereo, honk the horn while standing on the brake and if it doesnt burst then I'm good to go?

I'm all excited about all the weight reduction this will produce and my ability to carry a spare again for those longer trips.

 

[Daggar]

You could certianly try that and see how it goes. As an alternative, I might run a regular car battery on every day that I wasn't at the track. Just toss your motorcycle battery in before going to the start line.

Seems like the best of both worlds since you're probbaly not going to run any of those accessories you listed up there on your way down to the traps. hehe

 

[crazypete]

you're probbaly not going to run any of those accessories you listed up there on your way down to the traps. hehe

And race without music?!?

Thats just crazytalk!



Naw....I must be getting older though....or maybe because I just moved into an apartment and "lost my garage" but I cant really be jiggling stuff around as much as before. I've even had the crazy thought of <GASP!> leaving the catted midpipe in place after my inspection and leaving my pcv system hooked up. Moving the battery back into the enginebay is kind of my way of turning it back into a "regular commuter car".

Plus that factory battery tray is long long gone, I can lash a small battery in place without it looking totally ghetto but a fullsize would be just too much.

What I will do is if any such battery passes the turnsignal-honk-wiper test, I'll drive around on it for a week or two in the trunk hooked up with the original fullsize before doing the final swap.

 

[Daggar]

Ok... come back to this thread and report your findings! I'm thinking it might be of a lot of interest to the other weekend race warriors as well!

Good Luck!

 

[crazypete]

So I ended up getting a powermax GTX20-BS battery for a honda goldwing (a nice big fat cruiser bike).

It's dimensions are 6.8 x 3.4 x 6 and it weighs in at 13.6 pounds...a little heavier than I thought[SIZE=-1] but it has 260 CCA's and 18 amp hours (some online sources list it as 300 CCA..not sure the discrepancy). It's not a dry cell so it will have normal winter operation. Price 88 bucks, not the el-cheapo battery I was looking for but it's miniscule and has a CCA rating almost comparable to a small car battery.

Now....

I just have to say...

Motorcycle batteries are cool!!!

OMG, They ship dry and you have to like peel the top open and insert these funnels and fill each of the 6 cells with acid, let it "cook" for 20 minutes then drive these plug strips into place.

Apparently, they also come completely discharged. Even though the entire battery was warm after the filling, it apparently has no charge. I hooked it up with jumper cables in "jump configuration" and drove to work this morning (the ground cable fell off so it didnt get much charge). I shut down everything and tripped the breaker with the key "on" and it barely measured a volt or two.

It's sitting here with me at work and I'm using the only charger we have...a 5 hour AA battery charger using alligator clips..the lights on, so the charger thinks there is a battery there and it is feeding it...maybe it will pick up a bit of charge by tonight then I'll hit it with a real trickle charger.

I'll let you all know.
[/SIZE]

 

[Daggar]

So you're using a charger that's only cpable of a volt and a half? I don't think that's going to work. lol

 

[HISSIN50]

Every new motorcycle battery I ever got was supposed to be trickle charged (2 amps) only! You really shouldnt charge it full blast (setting the charger on 10 amps, 'start', etc). That said, people have reported dealers charging a new battery with more amperage.

Some mocyc batteries were famous for popping and never working again (if you search, you'll find volumes - it was a big deal for awhile). They're kinda fragile.

I remember others using a bike battery in the past but never heard back as to how it really did.

Good luck Pete.

 

[crazypete]

Some mocyc batteries were famous for popping and never working again (if you search, you'll find volumes - it was a big deal for awhile). They're kinda fragile.

How can you tell if it has popped?

I kinda trickle charged it at 6 amps overnight but it is showing "good" voltage: The voltage read 9 volts across terminals (bad) but then again the primary battery read 9 volts as well so I think my voltmeter needs recalibration and this baby is charged up as much as the main battery.

It was a disappointing first shot. First the car didnt want to kick in this morning on the main batt (which is unusual for this car) and then she didnt want to idle even fully choked (also unusual). She seemed to be running a bit rough too so when I hit the starter with only the motorcycle batt in place and it turned over only once or twice per hit, I wasnt that disappointed.

The connections running between batteries arent all that great either....the jumper cables are kinda funky looking and the ground isnt that great to boot.

Bottom line: I'm off in NY this weekend so I'm gonna let it charge at 2 amps then use the jumpers directly to the starter relay to see what this little batt is really capable of. Heck, somone had gotten this to work on a 160 CCA batt....this 260 should be cranking something major

 

[HISSIN50]

How can you tell if it has popped?

Because it's like someone cut your positive battery cable. It's an internal battery failure.

Sounds like a plan with charging it. A real voltmeter might be a good thing to pick up while in the city.
Good luck Pete.

 

[crazypete]

So in the end...it was a roaring success!

So I let it trickle charge at 2 amps for 2 days and when I got back, it was flowing next to zero amps, so it was fully charged.

I attached in place of the main batt and it gave a few tortured turnovers.

No good.

So I crawled under the dash and attached a jumper cable alligator thing to the feed side of the the starter relay and the other side to the motorcycle batt +. I then went from exhaust flange to - side with the other alligator thingy and POW! Cranks like a raped ape, full voltage. Did the honk and wipe with the lights on while standing on the brake, signaling and subwoofing loud rapmusic. The voltmeter moves a bit but then again, it does the same with main batt.

So in the end, if you have short wires and good ground, the little guys do the job just as well as a fullsize battery.

Tore my trunk battery cable out, ran a short wire to the enginebay, passenger side and made the ground to the exhaust bolt permanent. It aaaalmost fit behind the shock tower on the passenger side but not quite so it went in front of it.

Drove around for 2 hours yesterday, did at least 6 back to back cranks and this little battery shows no signs of giving up.

I have a trunk again!! Now I can race without silly trunkmount battery rules! Weeeee!



Thanks for the input guys! Happy motoring

 

[crazypete]

So during my "car needs to pass inspection" tuning then "car wont start" adventure yesterday, I must have cranked this baby for 2 minutes nonstop and it never showed signs of slowing down. I cranked it for half a minute....my father cranked it for a minute with me trying to set the timing.

I cranked it again and started 15 seconds in.

These little batteries are TOUGH!

I dont think my big batt ever did this much cranking!

 

[crazypete]

So on this lovely frozen morning of single digit temperatures, I thought I would give an update on the motorcycle battery situation.

It is....hands down....the single most resilient battery I have ever placed in any vehicle I have ever owned. Even my monster diesel truck batteries and top of the line car batteries have gone dead at one time or another but not the GTX20-BS. It was slightly slower cranking on mornings like this but it has never so much as hesitated and it has never gone dead even once even under hard long cranking.

For all those thinking these batteries are marginal, they most certainly are not. I dont know if they use a different kind of acid or something but I cant say enough good things about this little battery

It weighs a fraction of the normal battery and is 1/3 the size to boot!

 

[HISSIN50]

Pete, I wish the motorcycle batteries in my bikes did half as well as the battery in your car. Good stuff mang.

 

[crazypete]

Well, I finally killed it. While rewiring things, I let the alternator wire fall and ground and a HUGE spark later, all power was out. I attached a spare battery with jumpers and power came back on. I recharged the little guy but it wont even hold enough juice to roll the windows down after charging overnight.

So they are tough little batteries but once they "pop", they are toast.