D4D charging voltage

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

Hey dutchie thanks for the info, it makes perfect sense.

[Monty Lurker Find all posts View Profile Close Monty]

D4D Voltage output

Hi alll D4D owners.
I have a January n08 build D4D GXL Auto with Option Pack 2. Output voltage is rarely betty than 13.3 Volts. This seems low but is concistant with others readings.
Any one with a good story from Mr Toyota?
Monty

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

Hi Monty,

Sounds similar to what most of us are seeing. The local Toyota dealer was surprised at the low voltage and suggested I talk to their off site auto electrician. The auto elect said he thought it should be around 14.2 - 14.5 volts when the alternator was boost charging. He suggested I get the details of the side of the alternator so he could check the alternator against the manufactures specs. One thought was that Toyota is using an alternator with a lower voltage regulator.

Currently I am sill trying to get the details off the side of the alternator. Not a lot of room on the alternator side of a D4D. Obviously you need to have little Japanese fingers and arms to work on that side of the motor!!! :wink:

If some one can read the detail plate on the side of the alternator and post the details it would be greatly appreciated

John

[Monty Lurker Find all posts View Profile Close Monty]

D4D Charging Voltage

Hi All,
Just checked Prado Manual on CD and voltage should be in the range 13.2 to 14.8. Mine is at the very lower limit. The good book says replace the regulator if under load an unsatisfactory voltage is obtained. Will take this up with Toyota dealer and I am sure he will send me away and then I will head for an opinion from my auto electrician. Will advise

Monty

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

But is it causing a problem or are you just worried about it? Have a read of this. I cant find anything that states it's fitted to D4D Prados but like I have said earlier, I doubt all of you have the same "problem". At idle, an alternator working flat out would be one of the highest loads on the engine and because of the low RPM any load on the motor makes it run uncleanly. I'm not sure if this makes too much sense but I honestly think you have nothing to worry about.

http://www.radiolocman.com/news/new.html?di=2603

Matt

[leachy_9 Advanced Member Find all posts View Profile Close leachy_9]

The charging system on the D4D is designed to replace the charge used during engine starting which it can achieve with 13.2V -13.8v. What it does not do is FULLY recharge the battery. At this charging voltage the battery will only be recharged to approximately 80% of its total capacity. But the battery is sized so that at 80% charge the battery is more than capable of starting the vehicle. However, not fully charging the battery will decrease the life expectancy of the battery.
From a Toyota point of view, so long as the battery is recharged enough to start the vehicle and the battery lasts the 3yr warranty period then the design requirements are satisfied.
From an owners point of view this means the battery will need to be replaced more frequently then if the vehicle charged up to 14.4V, which is an inconvenience rather than a tragedy.
Where the real problem occurs is when you add an auxiliary battery. Typically auxiliary batteries are deep cycle, used to power fridges, and it is most desirable to have these batteries 100% charged to allow the maximum run time before the fridge cuts out you need to recharge. The only way to fully charge a battery is with an absorption voltage of 14.2v-14.6v (depending on the battery type). Clearly this is not possible by simply paralleling up the aux. battery via whatever solenoid. Thus to fully charge an auxiliary battery in a D4D some type of voltage converter is required. The products that I know of are:

Redarc BCDC-1206. This is DC-DC boost converter with a 3-stage battery charge output, which is exactly what is needed in this situation. The only issue I had with this is the relatively small 7A output.

Arrid Twin Charge: Again this is a DC-DC boost converter, but with a 25 Amp output. From the limited literature available, several phone calls and a shop visit I was unable to get (in writing) whether the output is a true 3 stage charger or simply a constant boosted voltage. Thus I was not willing to use this product.

The third option is to run an inverter to power a three stage battery charger. There are hundreds of inverters and three stage chargers on the market to choose from.
This is the setup I use: A 1000W pure sine wave inverter, 30amp i-charge battery charger and a 110AH DC-series Fullriver AGM auxiliary battery.

Leachy

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

OK, problem understood. It is not a warranty issue or design flaw. Just a design that doesn't work with the intentions of PP members. My apologies but I didn't really see it as a problem that a dealership mechanic should have to try and 'fix'.

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

About a month ago I posted the following question on another forum (4WD Action). This was an 'Ask the expert' section that was then answered by Alan Johnson from Piranha Offroad Products. I posted the question over a month ago but only yesterday did they post answers.

[i]Question:

Gilbo
I am looking to buy a dual Battery management system for by late 2007 model D4D Toyota Prado. However I have seen several posts on the internet that indicate me that the charging voltage for some new vehicles has dropped considerably.

A couple of tests on my vehicle after a bit of running showed a voltage of 13.6 volts. Others I have heard from are getting less than 13.4volts after the engines are run for quite a long time. My investigations seem to indicate that most battery systems change to charge the auxiliary battery at around this level. I am nervous that the auxiliary battery will not charge correctly. Especially when I may only stop for a short period then the relay may not even trip to the auxiliary battery at all.

I have noticed that Redarc have changed their product to trip at lower voltages as a direct result in these changes in charging systems (discussed on their July 2006 newsletter from the company)

Are my concerns unfounded or are there adjustments that can be made to the Piranha products to cover these situations? Everything else I read and hear about the Piranha system makes me think this is the system for me – apart from this voltage cut over situations.

I also talked to a guy the other day (who confused me with science) about the use of ‘Boost Converter’ to increase the amount that a battery can be charged to from a standard car alternator. I didn’t really understand. Are there possibilities using this equipment?

What do I have to do to a standard alternator to get it to charge a battery to close to 100% capacity? I am concerned that I need to run the vehicle for a reasonably long time if I discharged a battery to say 60% (after being in the same camp for a day). How do I get the largest amount of charge into the battery (without doing the battery any harm)?

Thanks for your help

Regards,
Simon

Answer:

Since approximately 1990 the standard accepted industry charge rate has been 14.2 volts

We have spoken to our representative from VACC, they recommended 13.2 -14 volts is a normal rate. We have also spoken to the Marketing Director Australian Pacific of Exide Technologies, he recommends 14.2 volts is a normal rate. We have been trying to contact Toyota Australia and have left messages, but we have not received a response to this date.

A boost converter should not be required unless the battery you choose as your aux has a specific change requirement, ie calcium or spiral AGM that simply go to sleep unless charged at 14.2 volts minimum. Most wet cell batteries will charge at lower voltage, eventually. However, the question is why 13.4 is this in fact correct or is it just your car. Is this a problem specific to one car or is it a Prado problem or is in fact a Toyota standard specification for this vehicle.

If in fact the charge rate is as you indicated is correct, I can not at this point determine, if you have a problem. We will keep you posted.

Seems to me like what we are say at PP is not the norm and there is a problem (yes, as mentioned before, not a problem for the vehicle - just a problem for all of us that want t decent charge in an auxiliary battery)

Other comments??

I will try to send copies of this whole thread to this person to get some more comments from him. I'll try to get to him direct. Anyone see a problem with this approach or mind if I copy their posts to Piranha?

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

Okay, found this on the net today while web shopping for a new fridge:

http://www.engelaustralia.com.au/cgi...%20Accessories

The Engel 12 Volt in car Battery Charger, which according to Engel is:

..."an electronic battery charger designed to charge lead acid batteries from a 12 volt DC vehicle battery. The charger uses its unique boost charge feature, stepping up to a charge rate allowing the auxiliary battery to properly charge and with its voltage sensing feature via the ignition circuit ensuring the main battery is not depleted while the vehicle is not running."

RRP; $139.95

Could this be used in conjunction with an existing Dual Battery System to boost the charge of the second battery? Installation seems relatively easy and the price is reasonable.


Jim

[leachy_9 Advanced Member Find all posts View Profile Close leachy_9]

Jim,

After reading the literature on the Engel unit my first question is what is the output?
At the bottom of the spec sheet it states "batteries that have not been used for extended periods will require a full cycle charge with a 240 Volt AC charger".
This indicates that the output of the Engel unit is just a simple fixed voltage, boosted above the nominal 12V supply. It would be fair to assume the output voltage is around the 14.4V mark which would improve the charging in a D4D. But since the rated input current is only 10Amps then the output current will be even less, probably about 8 to 9 Amps. Which is fairly low and it would take quite a while to recharge a battery that is at a low state of charge.
Bottom line: It would work but be slow to recharge (too slow for my needs at least).
Before installing one, I’d want to see a lot more information about the output of the unit, especially if using seal batteries.
I’m also skeptical of a product that makes claims like “The charger uses its unique boost charge feature” when there is nothing new or unique about boost converters.
I’d suggest that the Redarc would be a better solution as it has a true 3 stage output. – (still too slow for my needs but maybe ok for others)

Leachy

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

I've found that the new D4D will charge at a higher rate if a battery is discharged. I've seen mine up to 14.2 volts.
It seems to me that this newer logic in the Prado charging system makes independent battery management systems even more important than in the past. Unfortunately they are more expensive to buy but they don't work like the more widely used dual battery systems.
The more widely used systems charge the main battery and then open the circuit to the second battery, charging both at the same time. The problem with this is that it charges to the maximum of the weakest battery and forgets about the extra needs of the better battery. The end result is that the second battery may never get a full charge. It can be significantly down.
I run a Rotronics independent system that independently manages three batteries (the main, a second under the bonnet and one in the camper). They have two battery systems too. They also have the lower cost systems that I spoke about earlier. There may be other brands that do this too. By the way, I have no affiliation with Rotronics. The benefit of the independent system is that it switches the charge between each battery individually so that it has the full attention of the car charging system. It monitors each battery on a needs basis. This means that each battery is charged optimally instead of being dragged down by other weaker batteries in the system.
This system is much smarter and seems to get around the problem of lower voltages in the newer Prado charging system.

[leachy_9 Advanced Member Find all posts View Profile Close leachy_9]

The Rotronics is a good system that does work and for anyone looking to pay someone to install an off the shelf system it is a good option.
But I found that for the same dollars I was able to go the inverter / 3 stage charger route. This has the benefit of having 240VAC available in the car and providing the abiltiy to charge the battery from any 240VAC source (generator, caravan park etc.)

Leachy.

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

We seem to be skirting around the problem.

The fix may be as simple as changing the electronic regulator in the alternator. A few “we are not happy comments” to Toyota may be useful.

John

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

The Rotronics is a good system that does work and for anyone looking to pay someone to install an off the shelf system it is a good option.
But I found that for the same dollars I was able to go the inverter / 3 stage charger route. This has the benefit of having 240VAC available in the car and providing the abiltiy to charge the battery from any 240VAC source (generator, caravan park etc.)

Leachy.

Leachy this is also going to be my next move on the DB system. My current setup with redarc is only charging to 80% of cap, which realistically given that you should only discharge down to 50% is far from ideal. I've already got a CTEK so I'll be heading down this route soon.

Unless it is causing the cranking batteries to go flat or discharge them down to an unacceptable voltage range I'm sure Toyota aren't going to be too worried about your auxillary battery going flat. As long as they satisfy the relevant requirements which they are, why would they cop a heap of $$ in warranty claims when there isn't really a problem in the running of the vehicle? It's your modification to the car, if it doesn't work the way YOU want it to I'm sure they're not going to bend over backwards for you. It's like putting on bigger tyres that rub and sending it back in for a warranty claim to fix the problem...

Besides, how many cars on the road actually charge a battery more than 80% of capacity? As others have said the charge voltage will vary depending on the amount the battery is discharged. You really need to test it properly while in normal driving conditions and trend the data to get an accurate reflection of whats going on.

With modern electronics who knows how it's being controlled. The new VE commodores had a similar problem with the charging of the battery and a software patch was required to rectify the problem, so I'm not so sure that changing out the regulator will fix it.

Anyhow there's my 2.76 cents worth!

[leachy_9 Advanced Member Find all posts View Profile Close leachy_9]

We seem to be skirting around the problem.

The fix may be as simple as changing the electronic regulator in the alternator. A few “we are not happy comments” to Toyota may be useful.

As Crammy suggests making any modifications the vehicle's charging system / voltage regualtion is likely to cause Toyota to reject any warranty claim that has anything to do with vehicle electrics / electronics and in a D4D that includes engine and transmission.

Leachy.