FLAT <span class="highlight">battery</span> vs DRAINED <span class="highlight">battery</span>.

Submitted: Sunday, Apr 03, 2011 at 15:42

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Member - Phil 'n Jill (WA)

Well I finally made the cardinal mistake of hooking up the van without checking the frig setting and absolutely drained every last vestige of life from my 650 CCA battery, in my haste to get an early start on Satdy morning to get to a mate's workshop t fit an aluminium sheet over the boot area.

No excuse, should know better. But now I am concerned about the consequences of (heaven forbid) - copping this situation in an isolated area.

I have always felt comfortable with my 1900 am Jump Starter pack as backup, which I have only used previously on my 4 cyl Mazda and the odd family vehicle.

I hooked this up Satdy morn and had lights and momentary turn of the motor before getting the dreaded 'Click click click'. Now that was showing 13 v but no use on this occasion.

Called the son out of the sack to get the rescue Patrol over here, Hooked up my reasonably heavy duty cables and with his motor running - achieved the same result - so he kicked in his 2nd unit - still no difference. Noticed the cables were quite warm when removing them.

RAC to the rescue - boot load of battery backup - tried his straight off - same result only diff was his cables were HUGE and they were fairly kicking, which he suggested was indicative of how flat the battery was.

Problem overcome after he continued to 'power up the battery for a few minutes' before having another go. He also suggested we may have achieved the same result if we had run the Patrol across to the Paj for 'a while'.

Anyhow - as I was now an hour overdue at the workshop I expressed my gratitude and hit the road. My quandary now is, what would have occurred if I had a 2nd battery (isolated) would that have got me going? Considering the Patrol had two linked up (admittedly by jumper leads) I am now pondering my options.

The Paj doesn't have much room for a decent 2nd battery and in this case the Jumper pack wasn't up to the job - I am wondering whether I need to be carting a gen-set around 'just in case'. It seems to me that there are differing degrees of 'Flat Battery'.

Please factor in the knowledge that I belong to the group that believes 12v power is in the realms of 'black magic'

Thanking you in anticipation.

Regards - Phil

Phil 'n Jill (WA)

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Reply By: Mike DiD - Sunday, Apr 03, 2011 at 16:02

Sunday, Apr 03, 2011 at 16:02

When I jumpstart a car, I connect the leads, then run the engine at fast idle for several minutes to put charge into the flat battery.

The tiny clamp contact area on jumper leads would glow red and weld in place if it had to feed the 200 to 400 amps to the starter.

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Follow Up By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 17:50

Sunday, Apr 03, 2011 at 17:50

Point taken Mike Ta.

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Reply By: Notso - Sunday, Apr 03, 2011 at 16:06

Sunday, Apr 03, 2011 at 16:06

The big problem here is that you are trying to charge a battery from absolute dead flat at the same time as trying to start the engine.

Even if you had a fully charged second battery it may still have trouble starting with a dead flat main battery but as the RAC fella said give it a few minutes to whack a bit of charge into the flat battery.

So it would be a matter of suck it and see, and maybe carry a means of charging the battery with you.

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Follow Up By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 17:54

Sunday, Apr 03, 2011 at 17:54

Would that mean you could do the same with a 2nd cranking battery on the Paj - just switch the spare over to allow that to 'top up' the main - or would you expect it to just crank the motor over totally disregarding the flat main?

Rgds - Phil

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Follow Up By: Notso - Sunday, Apr 03, 2011 at 18:03

Sunday, Apr 03, 2011 at 18:03

Yes well it may have enough in it to do that, but I've never tried it with a dead flat "drained" battery hence my suggestion to have a means of charging your battery, eg a Genny.

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Follow Up By: Notso - Sunday, Apr 03, 2011 at 18:05

Sunday, Apr 03, 2011 at 18:05

Actually, you'd be better off swapping the second battery to the main position and the flat one to the secondary position then starting the vehicle. Assuming that the Isolator won't switch over to the secondary until the main one is charging.

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Follow Up By: Skippype - Sunday, Apr 03, 2011 at 19:38

Sunday, Apr 03, 2011 at 19:38

Notso
That would be the way to go....swapping over the second battery to the main position...
Skip

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Reply By: Allan B (Sunshine Coast) - Sunday, Apr 03, 2011 at 16:14

Sunday, Apr 03, 2011 at 16:14

Phil, I gather that the van is connected directly to the cranking battery at all times when the van is plugged-in to the Paj.

Maybe what you need is an isolating solenoid relay that only connects the van when the Paj engine is running.

Is there a battery in the van?

Cheers
Allan

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Follow Up By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 17:44

Sunday, Apr 03, 2011 at 17:44

Hi Allan

Yes the van frig only I believe is connected by dedicated Anderson plug.
There is a battery in the van and this was unaffected - that is a deep cycle AGM to service the rest of the van and has an ABR charging system which has been absolutely spot on.
I guess if a solenoid works on detecting when the engine is running that would solve the problem, rather than relying on my memory to disconnect and reconnect - drove out of one town in SA once and got to the edge of town before I remembered the lead hanging off the back - fortunately found the six to seven pin on the way back in - no damage done.

Thanks for the tip - Phil

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Follow Up By: Alllan B (Sunshine Coast) - Sunday, Apr 03, 2011 at 17:56

Sunday, Apr 03, 2011 at 17:56

Hi Phil, I guess that the fridge in the van is a 3-way, (12v-240v-LPG) and I would think that it has been wired so that the Paj can supply 12v to the fridge when on the road. This type of fridge draws large current when on 12v and relies on the vehicle alternator to provide the power which is only of course whilst the engine is running. Accordingly the feed to the Anderson plug at the rear of the Paj should be via a heavy-duty relay or solenoid which disconnects this circuit when the ignition is off.
An auto electrician could set this up fairly easily.

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Allan

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Follow Up By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 17:59

Sunday, Apr 03, 2011 at 17:59

Thanks again - will make that a priority I reckon - much safer.

Cheers - Phil

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Follow Up By: Member - Rod N (QLD) - Sunday, Apr 03, 2011 at 20:03

Sunday, Apr 03, 2011 at 20:03

You could also use a "Fridge Switch" motion sensing switch which isolates the fridge unless you are moving.

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Reply By: MEMBER - Darian, SA - Sunday, Apr 03, 2011 at 16:51

Sunday, Apr 03, 2011 at 16:51

I'm with you Phil (re the magic) - it's mostly bluff on the part of those professing knowledge about electric things - none of them have even seen an electron.

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Follow Up By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 17:57

Sunday, Apr 03, 2011 at 17:57

Won't even venture there (electrons) Darian - but I am planning to visit the Milstream in your pic, next visit - long overdue.... P

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Follow Up By: Mike DiD - Sunday, Apr 03, 2011 at 18:12

Sunday, Apr 03, 2011 at 18:12

So why do you think the ELECTRON Microscope was invented ?????

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Follow Up By: Notso - Sunday, Apr 03, 2011 at 19:01

Sunday, Apr 03, 2011 at 19:01

I don't think the electron microscope can actually see electrons!

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Follow Up By: Mike DiD - Sunday, Apr 03, 2011 at 19:33

Sunday, Apr 03, 2011 at 19:33

I don't think it's April first today.

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Follow Up By: Member - Bruce C (NSW) - Sunday, Apr 03, 2011 at 20:31

Sunday, Apr 03, 2011 at 20:31

Its magic alright that is why they call it electrickery !!!

At home and at ease on a track that I know not and
restless and lost on a track that I know. HL.

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Reply By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 17:47

Sunday, Apr 03, 2011 at 17:47

Thanks for all these responses - sorry bit slow getting back, just came down from clearing the gutters for our first deluge (we hope) later in the week.

Will wade through them and work out the best solution - some good tips there.

Happy travelling - regards, Phil

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Reply By: Member - Barry (NT) - Sunday, Apr 03, 2011 at 19:04

Sunday, Apr 03, 2011 at 19:04

Hi Phil

I think the best thing to do in your situaion would be connect the jump start battery direct to starter solenoid, start the car and let the car chage the battery and avoid the problems you had.

Sounds like all electronics survived this episode,,, maybe some luck involved here.

An easy way to do this is disconnect the + terminal and connect to jump battery so that you can reconnect to the + terminal to the battery as soon as the car starts. This way you don't break the circuit. Care need but possible.

cheers Baz

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Reply By: Member - Phil 'n Jill (WA) - Sunday, Apr 03, 2011 at 20:33

Sunday, Apr 03, 2011 at 20:33

Hi All - back again - couldn't get to the thread when I last tried - so off to Bunnings again for more gear to get the stone guard project completed - done now, which is just as well as we are running out of light here.

I am overwhelmed at the very helpful responses - thanks to all contributors again. I have some helpful tips now on overcoming the initital problem and how best to deal with the recovery process as well. Much the wiser now - on this issue. Standby for the next vexing chapter in my life dealing with vehicles and the things that make 'em work....

Cheers - Phil

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Reply By: Member - Bucky - Monday, Apr 04, 2011 at 04:45

Monday, Apr 04, 2011 at 04:45

Phil

Do not know just how many sets or you beaut jumper leads I went thru, from when I started driving.

Finally got caught with the 4x4's, as my "el-cheepo" ones were not good enuf, but I got put right by the mechanics at work.

I went heavy duty multi core wire. Almost as fine as hair, and basically no loss of power, even over 3 meters of lead. my only regret was I never got them made up to 5 meters. I paid $150, but another forumite did inform me that he had his made up, basically the same for approx $40, but he was in the know
Amazed at the difference in jump starting power from the leads alone.
Turned out to be welding lead, with extra heavy duty clamps, fully "swagged in".
There is basically all wire, and not like the Repco, Autoharn, "all plastic" leads.
Will hand them over to my grandchildren, when I go into the old folks home, in 20 years.

As far as isolators, and the wiring up of camper trailers, are concerned, Derek Bester from Sidewinder website
Has brilliant articles on how to wire up, and is backed up with good equipment.

There is also some very informative articles on power and electrics on this forum.

Cheers
Bucky

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Follow Up By: Member - Phil 'n Jill (WA) - Monday, Apr 04, 2011 at 08:55

Monday, Apr 04, 2011 at 08:55

Thanks Bucky - another useful tip - I too long ago, gave away the basic small wire leads, but your setup sounds like the ultimate. My leads have been good enough for quite a while, but there is always remove for improvement.

And yair - I'm a fan of Dereks gear too - his charger system is everything I hoped for and the diagrams I got at the time were most useful.

Have a good one.... Phil

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Follow Up By: Member - Bruce Y (Vic) - Monday, Apr 04, 2011 at 10:07

Monday, Apr 04, 2011 at 10:07

The leads that you buy from places like K-mart, Supercheap, etc are what are referred to as booster leads NOT jumper leads. The purpose of these leads is to connect two vehicles together, using the charging system on the running vehicle to charge the stranded vehicles battery to the point where it can start itself. Even if the leads look fairly thick slide the insulation back on one of the clamps and look at how thick the actual copper component is, you'll be amazed.

Years ago, (When stuck) we used to do a similar thing by putting the two vehicles bumpers together (Steel not plastic) to connect the negative side of the batteries together, and any wire we could lay our hands on (sometimes fencing wire) to connect the positive sides of the batteries, then leave the running vehicle at a fast idle for a few minutes before attempting to start the other.

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