Dual Battery TD 150 GXL

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: Dual Battery TD 150 GXL

As usual Derek, you have it all wrong.

First off, from the info you have on your isolators, they CUT-OUT, notice the correct terminology, it’s CUT-OUT, not kick out, but then again maybe one needs to kick yours to get it to work.

Anyway, your isolators cut-out at 12.5v, this means the isolator has allowed about 10% of the cranking battery’s capacity to be used for accessories.

Because the SC80 has a CUT-OUT voltage of 12.0v, this means the SC80 allows around 50% of the cranking battery’s capacity to be used by the accessories.

Another correction of your info. OPEN CIRCUIT voltage readings, as per your chart, are not useful unless the battery has been sitting in a NO CHARGE - NO DISCHARGE state for at least 24 hours not 5 hours and if you had any real knowledge of auto electrics you would know that the chemical reaction in a lead acid battery takes up to 24 hours to settle from when the last charge or load was removed from the battery, and it doesn’t matter how small the load might be, while there is a load your chart is useless because there is still a chemical reaction taking place.

So not only is your OPEN CIRCUIT chart useless, it’s totally invalid because dual battery isolators will have a load on the system while ever the isolator itself is operating.

Folks, the chart below shows the correct voltage levels.

Last but not least Derek, if you actually had any auto electrical experience you would know that there is no known test that can be applied to pre determine whether a chassis return earth will work properly.

If there is a low resistance point anywhere in the chassis route, it WILL NOT SHOW UP using an amp meter, because it only becomes apparent after a load has been applied for some time and the resistance causes heating at that point and this causes the poor earth return. The industry even has a name for it, based on how it works, it’s called a HOT-SPOT.

Furthermore the newer the vehicle, the more chance there is of a poor earth return.

Derek, stick to being a salesman and stop giving out "advice" in a field you haven’t got a clew about.

Oh and one more point, you are actually more likely to find a good earth return through the chassis of a trailer or caravan than you are in a vehicle, but again, if you had any real experience in this field you wouldn’t have got it back to front in the first place.

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

Re: Dual Battery TD 150 GXL

Drivesafe, I find it really frustrating that you change an interesting argument about a technical issue into a personal argument, to the point where moderators have had to lock threads.

In the interests of a good argument that actually answers the questions could we please stick to the technical issue.

A couple of questions:
1. Are the graphs for the same battery type?
2. If I am reading the posts correctly the first chart is for an open circuit battery that hasn't been used for 5hrs, what are the conditions for the second chart? This is useful info for understanding the state of charge of batteries.
3. What is the minimum voltage that a starting battery should be left at for say 4 days? The reason I ask is that if I discharge my starting battery to 50% and then don't start the car for a few days, the voltage will continue to drop due to background load (alarm etc).

Incidentally no-one has responded to my question about the engine vs the chassis as the primary earth point.

[ABR-SIDEWINDER Member Find all posts View Profile Close ABR-SIDEWINDER]

Re: Dual Battery TD 150 GXL

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: Dual Battery TD 150 GXL

So Derek, this proves your an expert, or just so desperate to cover up yet another one of your “advice“ stuff ups.

Hi krypto, while certain individuals parade around making out they are experts in something they actually know nothing about is bad enough and good for an argument, but when the “advice” and some of the products they sell are actually life threatening, I’ll always have a go.

I’m not hear to get sales, I’m here and on other forums, to keep up with how people use or want to use dual battery systems. I then use this info to my business's benefit.

If I can help keep info correct, I do but again, I don’t care if people take me at my word, and they shouldn’t, my posts should only be seen as a basis for them to doing their own research.

Safety comes first no matter what the consequences are and when people continually post up grossly inaccurate info, it needs to be corrected.

If people choose not to believe me, again I don’t care, but if it at least has them thinking and they start doing some independent research, my job is done.

Incidentally no-one has responded to my question about the engine vs the chassis as the primary earth point.

As to your question primary earth point, there is no simple answer because different manufacturers have different alternator to cranking battery earth paths.

Some, and the best way, bolt a decent size earth strap between the engine and chassis and/or directly to the battery.

Many actually depend on an earth return via the motor, transmission and the the transmission mounts. This later set up has been used by many different vehicle makes and is anything but ideal and I have heard of some extreme cases where the path has ended up through the gears themselves and has lead to the tips of gears being burnt. This was in some very old vehicles.

Even when there is an earth strap installed between the motor and chassis and/or battery, some times the strap is totally inadequate but usually, if a manufacturer has taken the time and expense to fit an earth strap, it’s usually a descent one, because it’s not the alternators maximum load they are catering for but the starter motors minimum load they what to cover.

So if you have easy access to where an earth strap is bolted to the chassis, this should be the ideal point.

[ABR-SIDEWINDER Member Find all posts View Profile Close ABR-SIDEWINDER]

Re: Dual Battery TD 150 GXL

Thank you Tim.

You always provide good entertainment.

entertainment = abuse

I love your photo on: http://forums.kombiclub.com/showthread.php?t=16859



I STILL CAN'T FIND A PHOTO OF 'YOUR' PRADO !!!!!!!!!!!

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

Re: Dual Battery TD 150 GXL

Drivesafe no one is enjoying your constant bagging of another forum member, really enough is enough. This forum was not construced for the purpose for which you use it. You certainly not painting yourself or your business, whatever that may be in a positive light!!

[CQ Wal Lurker Find all posts View Profile Close CQ Wal]

Re: Dual Battery TD 150 GXL

I agree with Hutch. Drivesafe - I find the manner in which you stage personal attacks on other Forum users as offensive and unnecessary.

Thank you.

Neale.

[samo Addicted PP Member Find all posts View Profile Close samo]

Re: Dual Battery TD 150 GXL

due to some more nice comments from a certain forum member he has earnd himself a holiday, so i suggest we all be nice to each other and stick to the topic which is a dual battery install in a td150 gxl. If this topic creates more arguments like the other dual battery topic in the 150s section i will lock it as well.

[brogers Advanced Member Find all posts View Profile Close brogers]

Re: Dual Battery TD 150 GXL

Unfortunately, the personal stuff got in the way of what otherwise would have been quite a good "debate"/discussion. Thats exactly why I joined the forum, to hear and discuss various opinions, and a mature debate would have been fantastic on this topic, especially hearing opinions from folk (right or wrong) who have at least had a go, or have some experience with dual batteries....some folk at the place where I work (some very senior and experienced aerospace engineers and Licenced aircraft maintenance engineers etc) have read some comments on the forum and agree with some folk, and roll about laughing at some other seemingly erroneous claims/statements...but unless people post and participate without the seemingly personal attacks on others, it makes it impossible to share and learn and move on....so, in summary, I have actually been left quite confused about some aspects of dual batteries for my Prado...yes, I have at least been able to understand some of the issues....but I have really onl,y created confusion in my mind, and doubts about which way to go....so, please folk, keep posting what you know/think or find out through experience, but its best to not be rude or seemingly attack, disagree by all means, but be polite and respectful....else we will be left with an incomplete debate on the topic, and folk like me will be even more confused than before...

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Re: Dual Battery TD 150 GXL

OK for what its worth here is my view on the whole dual battery subject.

It seems to me a lot of people complicate what is really a fairly simple system. I like to KISS (keep it simple stupid) so after also getting very confused reading loads about the subject here is what I have learned. Of course I have a 120 series.

Isolators? After getting confused by all the options I decided to ask my mates in our 4wd club what they have and whether they have any problem. Every single person answered Redarc and no problems! End of my research on that subject. Would I use a Redarc again if I had my time over? Well they are simple to install and work no problems, however if I was trying to save a few bucks I might even just wire up a $20 solenoid activated off the oil pressure switch.

What battery? My battery is mounted in the cargo area so I didn’t want a wet cell battery, I chose an AGM 100ah after looking at size, weight and cost. I didn’t worry about in depth calculations about usage as this can change dramatically if you change setups after the install, also I place more importance on charging than usage. I read lots about not connecting different types of batteries, and varying opinions on this. In the end I decided electricity is electricity and it doesn’t care what type of battery it is going into (just my uneducated opinion). So far the AGM along with the standard Toyota battery and a wet cell in the camper trailer everything works fine.

Cabling? I followed some advice from Drivesafe on this one, although he has contradicted this advice in this thread.

[ Drivesafe wrote in another thread:
Two batteries mounted side by side, 6mm auto ( 4.5mm2 ) with a 35 amp maximum continuos safe working capacity, 6mm auto is the minimum size but this cable will work fine.

Two batteries mounted anywhere in the engine bay, 8B&S ( 7.9mm2 ) with a 65 amp maximum continuos safe working capacity.

With a battery or two, mounted anywhere else in the vehicle or in a camper trailer or caravan, 6B&S ( 13.5mm2 ) with a 90 amp maximum continuos safe working capacity.

Note, for a single battery mounted in the rear of a vehicle, 10mm2 cable will work, but if you decide to add another battery or down the road you also want to charge a battery in a camper trailer or caravan, then you need to replace the 10mm2, so it makes more sense to run 6B&S in the first place.]

So I used 6 B&S cabling running an earth lead all the way between batteries as well. I won’t embarrass my self by telling you how small the wiring to my camper trailer battery is, but even with wiring that is way smaller than recommended it still charges no worries.

Having the D4D I decided to buy one of LieghW voltage boosters. Whether I really needed this or not I don’t know, however for $35 and 5 minutes to install, it certainly doesn’t hurt and it does add about half a volt to the charge. Money well spent (I think)

DC/DC chargers? I couldn’t work out why I needed one so I didn’t bother.

Charging! I tend to drive most days so I find that the alternator keeps up the charge no problems, even when I ran a 47 litre ARB fridge and a 39 litre Autofridge as a freezer for 8 weeks going to Cape York and back. The couple of times we stopped for extended periods (4 days) without driving much, where both in cities so I just got a powered sight and hooked up my $20 battery charger when we were at camp. If I was to be stopping for extended periods in the bush then I would look into solar.

I think that pretty well covers it. My best advice though is not to over complicate things. Use decent cabling, isolate the second battery, and choose the correct battery for the location. Inside the vehicle avoid wet cells and under the bonnet be aware of the heat and the affect that may have.

Cheers Andrew

[gregbme Junior Member Find all posts View Profile Close gregbme]

Re: Dual Battery TD 150 GXL

My two cents worth..........
AJ120, you hit the nail on the head applying KISS.
Yes, I also consider charging to be of at least the same importance as discharge.
Rule 1 Fit the biggest battery you reasonably can, and ensure it is very securely clamped without distorting the casing. A big killer of batteries is vibration.
I was coming out of the Bungles many years ago, and noticed my voltmeter fluctuating. Stopped, then swore. Battery had cracked at the +ve post and
leaked battery acid all over the bonnet, mudguard, and a bit on the A pillar. Respray req'd. Hope you get a laugh outa that one. Still don't know why
the heck it happened.
Rule 2 Understand how the system you choose operates. A bit of research and a few questions can save a lot of heartache when you're out in the bush.
Rule 3 Use cabling as recommended by an experienced, respected auto sparky.
Rule 4 Be realistic in your expectations regarding battery capacities and the devices you run from them.

My Prado?
I am about to install a manual switch (earths). Probably the only owner here with one of them, but I don't care.
I can see and control where 100% of the charge/ discharge is going. Plus I have installed one of Leigh's voltage boosters.
In maybe 25 yrs of using this method I'm comfortable with it. Make a rule to never parallel batteries. One reason is if one battery is losing a cell, it rapidly discharges the other. Same goes for charging. Out of habit, I also carry a multimeter and test light when travelling. That way you will likely never need 'em.
I will also run my B&S 6 cable from batt 2 (40A CB to +ve, cable to batt -ve) under the car and maybe inside the chassis rail to the Anderson plug at rear to charge my camper trailer batteries. Cable is inside convoluted tubing.

My qualification?
Certainly not claiming to be an expert on electrics, but am a qualified automotive mechanic. However, I have been out of the game for over a decade, so modern electronics are rapidly leaving me behind.
Must stress I am not preaching or trying to sway anyone's opinion, but some people can get very confused with all the information and fear campaigns.
Just trying to demonstrate how simple and stress free a good dual battery system can be. We're in it because 4wd camping is meant to be fun!!!!

So cheers, don't stress because it ain't rocket science, and have fun out in the bush.

Greg.

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: Dual Battery TD 150 GXL

I also carry a multimeter and test light when travelling.

Hi folks and apologies for getting off subject ( and the reason for my forced vacation ), and note, I am apologising for getting off subject and not for what I posted.

Enough of that.

Hi gregbme, mate, do yourself a big favour and this goes for everyone else with a test light.

Throw the thing in the garbage. They are one of the most dangerous tools you can use around a modern vehicle.

If you have your ignition turned on and you are using a test light to find wires, if you test any of the wires associated with the Safety Air Bags system, you can trigger the air bags.

While this is not only expensive, it can be very lethal. There have been a number of deaths in the US, caused by test lights being used to look for wiring in and around the dash.

Stick to using a digital multi meter, just so much safer.

[scottydooo Lurker Find all posts View Profile Close scottydooo]

Re: Dual Battery TD 150 GXL

Hi All

I'm new to the Prado Point forum and was really hoping that someone could help me out with a dual battery issue. I am currently installing a dual battery system in my 150 series petrol. Components are:

- Redarc BCDC 1220
- Interstate SRM-24 85Ahr deep cycle battery (lead acid)

I connected the system and have been monitoring for the past week with the fridge connected to an engel socket installed in the cargo area (57L engel combi). Worked great for the first few days but now there doesn't seem to be enough power to kick over the compressor in the fridge so I assume the battery is dead and not charging.

When I turn the car on, the redarc is in boost mode, moves through absorption and into float mode very quickly (15 min). Still no go with the fridge. I ran a couple of quick tests. Testsed the fridge to AC power, all good. Tested the fridge direct to cranking battery, no problems, Tested the fridge direct to Aux battery close to the engine as opposed to the cargo socket in case of voltage drop, did not start. So I'm ruling out the fridge at this stage and focusing on the wiring of the setup.

I'll be getting a multimeter in the morning and report back on readings but I'm convinced its the way in which I've earthed the system. For those that may be able to help, heres what I have done:

- Power connected from the main batt to redarc input, 8g wire, 30A AGU fuse close to main batt.
- Redarc earthed directly back to main batt, 8g wire.
- Redarc battery config wire secured to -ve terminal on aux batt.
- Redarc ingnition/sense wire connected to 12v acc wire for drivers side wiper motor.
- Redarc power output connected to Aux batt, 8g wire, 30A AGU fuse.
- Aux batt earthed to body next to air filter, 4g wire.

So the unit sits in standby fine when the car is off and correctly recognises the battery type. It also turns on when the ignition is switched on. So I believe that the connections to the redarc are ok but I'm questioning how its all eathed (particularly the aux bat to the body).

No shorts or blown fuses (except for my brain) so if anyone has installed one of these before and can assist or let me know how their setup is wired I'd love your assistance.

Appologies for the diatribe, but heading to Fraser for easter and keen to get it sorted.

Cheers

Scott

[ABR-SIDEWINDER Member Find all posts View Profile Close ABR-SIDEWINDER]

Re: Dual Battery TD 150 GXL

I'll be getting a multimeter in the morning and report back on readings but I'm convinced its the way in which I've earthed the system.

Hi Scott

You need the multimeter and as you back probe the wiring you will find the fault, it may just be a bad connection or crimp.

Regards

Derek

[D4D Addicted PP Member Find all posts View Profile Close D4D]

Re: Dual Battery TD 150 GXL

Wow, how did I miss this thread :wink: