The Toyota Landcruiser Owners Club

Crispin · Posted: Mon Aug 31, 2009 21:42 Post subject:

They are nice and simple in the sense that you open the cardboard box and it's all there and working. But they are so overpriced. I think I spent about 100 on the PC. The ready built ones are 200+ A bit of a premium to pay. The monitors are still expensive, where ever you go Sad

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Crispin
Have Snorkel, Will Swim

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Crispin · Posted: Fri Sep 11, 2009 8:49 Post subject:

Finally got around to finishing everything. Cables all neatly hidden away, rear seats back in place, carpet srewed down and all panels back where they should be. Best part, no spare screws. Pretty impressive.

The PC has been in and working for about 2 weeks now. Just not got around to finishing it off.
Next comes the GPS stuff and then Jon's keyboard type thing.

For the last two weeks I have left the PC on. it goes into standby after 3 hours. Not ever got a gint of the battery being low. Until this morning.....
As I turned the key starter did half a revolution and nudda. DAMMIT. Quick run up to the local garage in wife's car, purchase some jumper cables, back down. The engine (2.0L) note on her car changed when I hooked up the leads. Guess two empty 75AH batteries are thirsty. Had a quick cup of coffee and while the batteries made small talk. Hopped into LC and starter reluctantly turned over. Alfa again protested. LC fired up and all is well.

The reason it went flat? I had left my home PC connected to the car pc so it never went into standby. Something to remember.
What I want to confirm though is the PSU I am using (the one Jon spoke of) should shut everything down when the battery gets to 11.8v. Not sure why it did not. Will give it a test. Stupidly though, I did not actually measure the battery voltage before charging. Could it be that the batteries may have been at 11.8V but did not have enough capacity to turn a cold LC engine?

Live and learn...
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Cheers,
Crispin
Have Snorkel, Will Swim

wildsmith · Posted: Fri Sep 11, 2009 9:20 Post subject:

Might be worth checking your jumper settings on the PSU? Generally the battery voltage is proportional to the remaining capacity but some battery faults only show themselves under load e.g. starter current. Best thing is to connect a multimeter and see what's going on. One or both of your batteries may be warning you winter is coming Wink

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Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

Crispin · Posted: Fri Sep 11, 2009 10:33 Post subject:

The PSU is currently set to dumb mode which will not turn off the PC at all. I assumed even in dumb mode it would still protect against discharge. Will have to re-read the documentation tonight.

While I was doing the wiring yesterday the batteries were giving me 14.2V which actually confused me. I know my meter is about 0.4V out but after half a day of having the radio on, interior lights etc, batteries would not read that high. I was measuring at the cig lighter and not at the batteries. I meant to but crying babies apparently come first...
Will have a poke about tonight.

On the wiring note, there was another thread a while back where everyone was talking about not relying on the chassis as a ground. While waiting for something I had a poke at one fo the screws holding in the gearlever plate. A simple continuity test confirmed it was earth. Actually checking the resistance between it and a known good earth (my cable) showed a resistance of 63 ohms. Between my ground and the ignition barrel was 4 ohms. Anything substantial unfortunate enough to use these as grounds would not work very well. :S
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Cheers,
Crispin
Have Snorkel, Will Swim

Nuclear Chicken · Posted: Fri Sep 11, 2009 10:57 Post subject:

The chassis itself is a good ground. It's the connections to and from it that give the poor results. Wink

On another note, you should be able to measure battery voltage reasonably accurately at the cig lighter. When it's on 'no load', it will indicate as near as dammit the battery volts as there is effectively no current flowing. Of course, if you have a few suspect grounding points with resistances of what you have measured, that's a different kettle of fish altogether.... Shocked

If in doubt, straight to the battery.
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'04 KDJ120R LC5. Died 17th Dec 2010. RIP.

garystockton · Posted: Fri Sep 11, 2009 10:57 Post subject:

That were me - I'm probably paranoid a bit on this - I really don't want any hassles, so consequently I will be running 25mm square earth wire to the charging battery this weekend for my third battery install, along with the mega-fuses on the positive, all cable wrapped and grommeted .... think that'll keep me busy for a while - that and the snorkel of course!!
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I'll be more enthusiastic about encouraging thinking outside the box when there's evidence of any thinking going on inside it.
- Terry Pratchett

wildsmith · Posted: Fri Sep 11, 2009 12:00 Post subject:

In dumb mode it's just that - as dumb as a regular ATX PSU Laughing

14.2v means either the engine was running, a charger was connected, or you have bad meter! So long as you have a good connection to the body / chassis that's the best way to do it IMO. A cable all the way back to the battery for every device is just adding even more points of potential failure and may create a longer path with greater resistance not forgetting earth loops, especially in multi battery installs. But that's just what I think and despite being very free with my opinions I'm actually not an expert Laughing

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Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

garystockton · Posted: Fri Sep 11, 2009 12:18 Post subject:

Sory - misleading on my part - only one pair of cables all the way back, then the 3rd battery in the back, with (if necessary) a small fusebox hanging off that for stuff.... At the moment it'll be just the fridge and the inverter Laughing

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I'll be more enthusiastic about encouraging thinking outside the box when there's evidence of any thinking going on inside it.
- Terry Pratchett

wildsmith · Posted: Fri Sep 11, 2009 13:14 Post subject:

FWIW my rear battery's have the negative terminal connected to the body nearby via a nice thick cable and a big bolt. The body shell is my nice high capacity conductor between everything that needs it Wink

_________________
Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

Crispin · Posted: Fri Sep 11, 2009 13:30 Post subject:

wildsmith · Posted: Fri Sep 11, 2009 13:59 Post subject:

I think it's 12.6v for a fully charged battery, 13.8v when the engine is running, higher if it's not fully charged. A brand new good quality battery will struggle to give the stated capacity and if you use it all you will kill it Confused

An older battery is probably capable of around the 80% capacity mark if it's still a good un. A car charging system cannot re-charge the battery to full (reduced) capacity. So after a long run on a reasonably good battery you maybe have 70-75% of the stated capacity available if you're willing to kill the battery and your devices will run on the very low voltage that takes you to ... So I'd say that means only about 50% of the stated capacity is actually available to you for long term usage on an old battery, maybe less. Now stick a big drain on it like the starter and it's a wonder any battery ever works according to my logic Laughing

Some of the higher tech battery's like the Elecsol carbon fibre jobbies I have are able to retain their full capacity and for a long time. The construction of the plates doesn't tend to deteriorate like conventional plate construction. The 4 stage DC-DC or mains chargers can charge your battery to whatever it's full capacity is so in an ideal world an aux battery would be charged via a DC-DC charger rather than a direct connection to the other battery / alternator but they're quite expensive. Mine get's plugged into a 4 stage mains charger (via the towing electrics Very Happy

) to keep the batteries healthy. Obviously just being connected via a relay does work but with reduced capacity as a result.
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Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

Crispin · Posted: Fri Sep 11, 2009 14:10 Post subject:

not sure how old my batteries are so you might be right with the 50% thing. I'll get them tested and fix pc. Went out at lunch and forgot to turn PC off again. Might be walking home.... (wonder if I could jump start of Mark's smart car Laughing

)
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Cheers,
Crispin
Have Snorkel, Will Swim

Crispin · Posted: Fri Oct 16, 2009 23:12 Post subject: It's dead...

Short lived was my LCupter... Crying or Very sad

On Wednesday had to ensure the ABS was working when some *beep* *beep* *beep* *beep* *beep* *beep* woman in a little *beep* *beep* *beep* *beep* car pulled out in front of me. I wish I had a steel bumper.

While there was no impact (I don't think you could have slipped a playing card between my bumper and her door), everything that was once in the back of the car was now in the front. There was also a horrid smell emanating from my seat.
The 'puter, which was under the seat and not able to move, turned off, never to turn back on again. Looks like the motherboard is dead. I have no idea why...
Tried new PSU, memory etc etc. The LEDs on the board come on, nothing else.

Back to the beginning then.
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Cheers,
Crispin
Have Snorkel, Will Swim

wildsmith · Posted: Fri Oct 16, 2009 23:31 Post subject:

Oh dear, that doesn't sound like you will be able to put the magic smoke back in Crying or Very sad

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Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

Crispin · Posted: Fri Oct 16, 2009 23:33 Post subject:

nope - looking for a replacement now Crying or Very sad

Next time, a smoke tight box.
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Cheers,
Crispin
Have Snorkel, Will Swim