How many amps to start a 60? (1 Viewer)

[woytovich]

So how many amps draw off of the battery would be typical to start a 60...

...in warm weather?

...in very cold weather?

How about to run the starter with the vehicle in gear going up a steep hill AND starting?

Just curious...

mark

 

[Mace]

What battery, what cables, how long are the battery cables, how hot is it, how cold is it, what starter, how old is the starter, what type of oil, what viscosity of oil, what's the compression, is the engine hot, is the engine cold, is the starter hot, is the starter cold, how old are the bearings, what gear, high range or low range, what viscosity is the gear oil, what type of gear oil, what size tires, low or high range, how steep is the hill, what material is the hill made out of, is the ac on, are the wheels turned, 2wd/4wd...

Essentially, there are a huge number of variables and no such thing as "typical"

 

[woytovich]

Ok Mr. Smarty Pants...

How about under IDEAL conditions... like when the cruiser was new in 1985 (it is a 60), on a clear low humidity day in the late spring, around 70 degrees, slight breeze, fresh oil change just after the 500 mile break-in period?

Failing all of that: How about a RANGE? How about a MINIMUM to turn it over and a MAXIMUM given an old 60 that is in generally good working order - without any "extra" stresses?

Are we talking 50-200 amps or are we talking 300-900 amps?

Or is it really impossible to say other than the MAX is the MAX the battery is capable of and the minimum is...?

 

[CardinalFJ60]

I have no idea...buuuttttt....

...the stock alternator is rated like a measley 55amps...so no more than that I'd assume. However, batteries 'carry' up to 1000 CCA so...really, I'm no help. what's the minimum of those 1000 CCA in the optima do we use or need? that is my question, too.

 

[HJ61 12HT]

I think the starter motor is about 2.5kw.
So with 12V you could pull about 210 Amps average.
Probably more like 400A for a split second as the motor starts and 100A as it turns the engine over...

 

[Mace]

So are you looking for the minimum battery size or what is the end game?

There is no "typical" that is why people tend to buy the biggest battery they can fit in their cruiser. Only way to figure out what your cruiser draws is to actually test it using the equipment on it.

I run 00 welding wire and soldered connections on my cruisers to decrease resistance. Amps available from the battery does not equal amps provided to the starter.

 

[OGBeno]

I think the starter motor is about 2.5kw.
So with 12V you could pull about 210 Amps average.
Probably more like 400A for a split second as the motor starts and 100A as it turns the engine over...

The gasser starter is significantly smaller is kW. Diesels are in the 2.5-3.0kW range.

The 2F is a 1.0kW starter.

 

[woytovich]

The gasser starter is significantly smaller is kW. Diesels are in the 2.5-3.0kW range.

The 2F is a 1.0kW starter.

So 90 amps?

What does the 1.0kW mean on the starter?

 

[woytovich]

So are you looking for the minimum battery size or what is the end game?

Mostly just curious...

BUT it came up because I was thinking about a dual battery set-up...

...and then the idea of mounting the battery(s) in the back of a vehicle (because I have here a long battery cable that came out of a BMW or something that has the battery in the trunk).

And THEN I was thinking that that wire SHOULD be fused and that led me to wonder what fuse size one would need on the wire from the battery to the starter.

Got it?

 

[dsmud4u]

Aren't most of the isolators in the kits rated at 200 amps

 

[lovetoski]

Batteries in back make sense to me. Takes lots of stress off of the front springs. I'd fuse this at least 50% above the max watts of the starter, maybe 100%. That will still be way below the max battery output. I'd also select wire gauge that was above the fuse limit. But, I am a belt and suspenders guy.

 

[TobyB]

BMW runs lots of batteries- in- trunks setups- none are fused. Kinda scary, but then, if it shorts, what's gonna fry? The cable is GIGANTIC, so it probably won't even get warm before the battery blows up. And they use pretty big batteries- bigger than the FJ60 by quite a lot.

Mark, your question really is, what;s the maxumum rating for a crank cycle , Because there's a time factor
to all current limiting devices, and you have to factor that in.
So you might need a 400a semiconductor fuse, but only a 100a motor fuse- since the motor- style fuse
is designed to handle 400a for 90 seconds, THEN pop.

All that said, I bet a 200a marine style circuit breaker would work just fine.

<edit> it would never pop under normal loads, but if the cable shorted to ground, it would pop before anything exploded or melted

t

 

[woytovich]

NOW we are getting at the crux of my question... thank you all.

"...50% above the max watts of the starter, maybe 100%."

"I bet a 200a marine style circuit breaker would work just fine"

Is this given that a 2F starter is a 1kW starter? (90a-ish)

Mark

 

[Elbert]

doubt you would gain any efficiency by moving batteries to the rear cargo area or having a 2nd battery in the rear cargo area that is tied to engine cranking. If you need a 2nd or 3rd battery to power a refrigerator then isolate it and set it up in the rear.

If you need better batteries for engine start...you judge by CCA (cold cranking amps), the higher the number the better the battery. Long runs of battery cables are not efficient. 600CCA is good, north of 600CCA is better.

I know other mfgs have batteries in the trunk and many race cars have them in the trunk...some of those deal with safety rules and then some deal with space limitations.

Yea it would work but what would be the (+ / advantage), dual battery trays are easy to get...the guy "stainless" does a great job of making them and they are generally available. Where you have two batteries under the hood, which if you have a stock engine...is very easy to do and setup.

 

[woytovich]

The goal FOR ME wasn't a rear battery install - although that would be interesting with a rear winch install - it was to determine the necessary fuse to use with a starter.

 

[Elbert]

OEM fuesable link?

 

[Mace]

OEM fuesable link?

Won't even come close to handling the power required..


There is a reason auto manufacturers do not put fuses on the battery cable. They are not needed.

 

[Elbert]

yea... my bad for that.. (don't consider the fuseable link)

I don' know the number but Its fairly high amp draw for the starter...

I have a simple dual battery setup and if one of my cables shorts...its going to be interesting...

 

[woytovich]

I have a simple dual battery setup and if one of my cables shorts...its going to be interesting...

That is one way to put it...

...safety first (or at least second)!

 

[Elbert]

yes...It will be my own little fire hazard...I'm running some fairly heavy gauge welding cable to join the batteries which feed my truck and then power my winch. I assume I will have a nice meltdown if something happens. But to really protect that I would need some really high rated "industrial type" fuses...

I'm sure a starter draws north of 200AMPs and the warn 9000 winch under load draws an incredible amount (you can see the numbers on warns site).

I probably need to hunt down some large fuses but have been too lazy to do so. I might look at one of the large amp rated marine switches next time I swap out the cables so I could potentially turn the power off in case of a accident or issue.