Jumpstarting WITH a Trailblazer

[H80N]

Moe
in CV mode I would expect that the same rules apply as laid out by Andy...... HOWEVER!!! In CC mode I personally would not play.. Welders by the nature of welding tend to be pretty robust by design...so would expect the welder to be pretty safe.... but CC mode makes it a drooper... with an open circuit voltage somewhere between 60 and 80 volts.... and I would be very concerned about warping plates in the battery and possibly dielectric breakdown somewhere in the alternator/regulator.... making smoke due to massive overvoltage.. not having tried it... this is just a worst case guess..
hope this helps

[moe1942]

Heiti,

Yes the Bobcat is CC and CV but no meters. I have have inductive amp gauges and amprobes though.

moe1942

[H80N]

Moe
on my chevy/gm trucks when jumpstarting the voltmeter will regularly get to 18v..... to the best of my knowledge... you do not want to raise the voltage... amperage will fall according to how much draw from the system being charged...think you are referring to work being done in watts... and yep higher voltage will probably make more watts (up to the welder/charger limits).... but that is not neccesarily a good thing.... does your Bobcat have a CV mode??
hope this helps
Heiti

[moe1942]

Heiti,

In auto charging systems, if the regulator is working properly(GM) the alt should not put out more than 13.8-14.2. If the battery is in good condition they can handle much more for short periods of time. As Andy pointed out it is a good idea to feed it slowly.

In order to reach the full potential(Amps) wouldn't the volts have to be cranked up high on your TB or any CV source?

I know we are hammering this subject pretty hard but considering the stakes..........


moe1942

[moe1942]

Didn't really put enough info in my question and I'm posing this in general terms, not specifically using a TB..

I'm trying to visualize exactly when and how the leads are connected. Unit off, hook up leads, crank unit and slowly ramp up watching volts/current? Would backfeed before the welder is putting out cause internal component failure? Or would welder be cranked up and be in the run/idle position and then crank the volts up?

Since this topic is out in the light of day it might be a good idea to nail this procedure down before "trying it at home." If done wrong the fire works could be spectacular!!! And too, everytime I assume something my wallet gets lighter...

I'm basing my thinking on the way a battery charger with boost feature works. Connect leads then go to boost.

Hate to be a PITA but I can see where my Bobcat or AEA=200-L could have other uses. Do I dare say electrolysis?


Think I had better duck and cover...


moe1942

[H80N]

Moe
automotive charging systems are pretty imprecise.... and pretty immune to voltage fluctuations.... have seen 12v systems pump 18v into a flat battery.... my greatest concern was protecting the TrailBlazer......
Thanks
Heiti

[H80N]

Moe
never done it so I do not know for sure... My customer asked me the question and I asked you guys..... but If I followed Andy properly..... take an initial voltage measurement.... and slowly ramp up from there... while monitoring Amperage....(gotta warm as well as charge em) ....if Amps spike... then abort... as that indicates internal battery probs....
thanks
Heiti

[moe1942]

Heiti,

What is the sequence of events when using a CV power source for purposes other than welding. I only like fire works on the 4th.




Thanks for the heads up on the rain Don. Can't wait. I want to thank y'all for taking some of the steam out of these systems. Y'all are really gettin hammered in some areas. Took the scoot out for a ride this afternoon to get the oil moving. Fixin to cover it back up......


moe1942

[ASKANDY]

That wasn't a nutty question! I'd say it was "thinking out of the box"

[H80N]

Andy
THANKS.... knew you had probably tried it... and as always a common sense reply.... do not expect to do too much of it but it was an interesting question... 12v systems being nominally 13.8v and 24v systems being nominally 28v (like aircraft power)... would slowly ramp up to, and not exceed these values.... for the given equipment...(have meters and Amprobes so no prob) my business is welding and not road service but it is nice to know that my trusty versatile Trailblazer 301G is good for yet one more thing.... WHAT A MACHINE!!!!
and thanks to all who replied to this nutty question
Heiti

[DDA52]

Re: cold cranking amps

Originally posted by fun4now
. i would have to think heavy equipment batterys would be even hier. .

My 3176 CAT has 3 1000 amp batts in a series. My Cummins M-11 has 4 750 amp batts in series. If one of those batts are bad, there is no joy in the trucking world that day! MY Case 1845c only needs about 750 amps to fire up, freezing, cold or hot.

Don



Moe,
More rain for us tomorrow!

[ASKANDY]

Heiti,

I've done this in the winter when I lived in Wisconsin. Trick is not to put too much voltage over the current battery level. So if the battery is at say 9 volts, start your unit near there and move up slowly to 12-14 volts or some equipment (as you know) runs on 24V. This will not shock the battery. It's not really recommended by the factory cause no way to tell the amp draw from the machine. If amps are rising too quick, it's 'cause a cell in the battery is shorted and battery failure will soon come. We build engine drives with battery charge circuitry in them to take this all into account. So, if you have a volt meter and amp clamp and think you want to take the chance, the answer is yes it will jump some equipment as long as the jump draw doesn't exceed welder capacity.

I was jumping an old malibu winter beater about every 3rd morning.

Good luck!

Andy

[walker]

Just take your ground clamp and hook it to the frame. Then stick an electrode in the stinger and stab the big starter wire connection at the starter. Then have someone start it. I like this method as it keeps the sparks away from the battery. However, you could connect one clamp on the battery and then ground the other on the frame. I would not do this on someone elses equipment due to the liability, I see this method only as a means to get out of a bind.
Oh, also, make sure you know which electrode is POS and NEG, in other words know if your machine is set up DCEP or DCEN.

[fun4now]

cold cranking amps

moe1942 may have a good point most car batteries have 600-800 starting ampsthats what thee cold cranking amps rating is for tells you how much your battery will put out in a starting draww. i would have to think heavy equipment batterys would be even hier. i know in the army our 2 1/2 ton trucks and m113's (armored personell cariers) linked batteries in series for more juce thouse old deasels would use far beond 300 amps on startup in the cold.it might be differnt but i think an amp is an amp. 300 amps weld well because the electrode is small and the power is constant . so although it seems like a lot in starting amps its not.

[moe1942]

Heiti,

Sorry for getting your thread off track. I don't know a thing about the TB so I can offer no help in that respect. IMHO though I would say that 300 Amps is probably not enough juice to crank a cold piece of construction equipment.

Thanks for clearing up my 115/145 comment....

moe1942