DC - DC Charger Vs Smart Solenoids

[D4Dazz Member Find all posts View Profile Close D4Dazz]

Piggy, it was hardly a personal attack more of an observation. But if I have offended anyone I sincerely apologies. Free to close it down if you like, it's sort of got off track anyway.

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

Can someone tell me, what is the max voltage my alternator puts out? I have a 2007 D4D. is it limited?

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

Yes your 2007 has a low voltage output alternator, voltage will be
in the range 13.5V-13.8V depending on the alternator temperature.

[Dingle Lurker Find all posts View Profile Close Dingle]

Hi MJ and from the voltages you posted up, they are the pre 2013 operating voltages.

I’ve not seen a 2013 Toyota with voltages below 13.6v.

Note, this is just what I have personally observed and does not mean they don’t go lower, but I haven’t see, or heard of lower voltages in new Toyotas.

Anyone with a new Toyota and has the time and patients to check their operating voltages while they are driving, please post up your readings.

Drivesafe,

October 2013 built GXL - Voltage after startup with battery charged the night before 13.87v. Down to 13.5v within 20mins. 13.47v at the 1 hour mark @ 24°C outside temp early morning driving around town. I don't imagine it was very hot under the bonnet.

Cheers

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

Hi Dingle and thanks mate.

There is obviously more to the operating voltages and I think it will take some research to get a better idea of WHY the operating voltages are what they are in different Toyotas.

You say you charged the battery over night. Perhaps this had some effect on what the operating voltage was to be.

The reason I suggest this is that the last LC200 I measured, the owner had just driven constantly for over an hours and we measured his LC200’s voltage while it was idling straight after he arrived.

This was a hot day and the reading was 13.69v.

Dingle, one question for you, where did you take the voltage reading, at the cranking battery terminals or inside the cab?

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

Another data point - After a short 30 min drive home on a 35 deg day the voltage had dropped to 13.8V. My setup has a diode from ABR Siderwinder and as I reported earlier in the thread, reads up to 14.6V on startup on cold mornings (near zero).

Readings are all taken at the 12v socket on the console.

Obviously Toyota allow a large voltage variation.

[Dingle Lurker Find all posts View Profile Close Dingle]

Hi Dingle and thanks mate.

Dingle, one question for you, where did you take the voltage reading, at the cranking battery terminals or inside the cab?

I took the readings at the battery on startup and then from an accessories socket in the cab from then on. I wouldn't have expected any difference as I wasn't drawing any current. Could be wrong - will satisfy my curiosity when I get a chance.

Mine has running lights on permanently (non LED). Potential difference also I guess.

Wishing I had Cityslicker's alternator. What's your address? You'll never know I was there.

Getting about 14.2 with Leigh's diode in now. Only just put it in so not well tested. It's working well as designed but 14.6 or so would be ideal as the camper batteries are a long way away. I've gone with big ass cable so will be interesting when I give it a run at xmas.

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

Hi Dingle and sorry mate but taking voltage readings anywhere other than at the battery terminals is open to many factors effecting the readings.

You can get as much as 1v difference between the battery terminal voltage and the cig socket in the dash.

Also, having 14.6v in one vehicle and getting 14.2v in an identical vehicle actually has nothing to do with the alternator ( or the brand of diode ) but will have more to do with the state of charge of the cranking battery in each vehicle.

I base this OBSERVATION on the feedback from a number of members, including yours and especially yours.

You posted you charged the battery before you carried out the test voltage readings and I suspect you had a lower operating voltage because your vehicle had monitored a fully charged battery at start-up and as such, the battery did not need the higher voltages.

Where as Cityslicker may have had a battery in need of a bit of a charge and his vehicle decided that his battery needed a higher operating voltage to get the battery into a higher state of charge.

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

Leigh,

I've never tried to charge the boot battery with the diode setup. I went with the DC-DC setup a few years before I installed an underbonnet dual battery. I run 13sqmm positive and negative to the boot. I run 25sqmm positive and negative between underbonnet batteries through a Redarc. The issue I was having with a two different underbonnet deep cycle batteries after a deep discharge was after a full day of driving, I'd disconnect the battery and let the settle unloaded for a hour and measure the voltage. I'd get a reading of 12.4-12.5V. I had this on a 2 year old deep cycle and a brand new one. The battery supplier suggested due to the calcium content, after a deep discharge, a slightly higher float voltage or float charging at a lower voltage for a few days would be required to recover full capacity on the battery. When charged with a bench charger, the battery bounces back no problems.

Don't get me wrong, I have no issue with the diode setup. It serves my purpose for the way I use my batteries now. The issue I was experiencing was due to the composition of the battery plates and the lack of knowledge I had when I purchased the battery. If I had an antimony/antimony battery I don't expect that I'd have the issue I came across. Some batteries require longer to fully charge at 14.0-14.2 volts after heavy use.

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

No probs,

I thought from your original post you had tried to charge the boot battery and couldn't charge it.

A boosted alternator charges at around 14.2V - 14.4V a DCDC charger around 14.4V at the same ambient there really isn't much difference.

Agree with a full calcium battery a regular charge with a charger that has a calcium setting would be a good idea. Having said that the manufactures of calcium batteries where worried that the batteries would suffer a premature failures when used in vehicles with charging systems that were not specifically designed for charging calcium batteries this has been found in practical applications not to be the case.

Leigh

[Kel Lurker Find all posts View Profile Close Kel]

I am also looking into the DC Charger and Isolator world. And another point that REDARC brought up was that 'current sensing' in new vehicle electrical systems means that all additional electrical accessories must be grounded to the vehicle chassis or body, not to the main battery negative terminal. I am guessing that if you don't the ECU will sense too much current and automatically lower the alternator voltage to save fuel and emissions? That could mean that these diode boosters may not have an affect as the ECU could interoperate it as too much and even turn the alternator off?

Whats peoples thoughts on this?

Heres a link: http://www.redarc.com.au/images/uplo...-sept_2012.pdf

Hello Warnsie

I've gone down the track of the Redarc DC/DC charger. You're on the money regarding changing alternator output according to load detected by the vehicle computer. The redarc charger I purchased has the prefix LV in its model number. This means "low voltage" allowing the charger to maintain its output of 40amps (I plan to service a large caravan battery bank) from input voltage from as low as 9v. This is to cater to reduced output of modern vehicle alternators. I had wanted to connect the charger to the negative terminal on the starter battery (along with the positive wire on its respective terminal). I was advised to stick to the manual and connect the charger negative lead to the vehicle chassis. The reason for this was that it could then read the electrical load being produced by the alternator and adjust its charging accordingly. The connection I had proposed would mean the charger would have been reading what was happening in the vehicle battery only which had not relation to the output of the alternator.

Although I didn't need the LV charger for my Prado (120 series 2003) its alternator is not one of the smart modern ones, I bought the charger for possible use with some more modern vehicle in the future.

Kel

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

A boosted alternator charges at around 14.2V - 14.4V a DCDC charger around 14.4V at the same ambient there really isn't much difference.


Leigh

Hi All

I keep seeing these figures, however my boosted alternator produces 13.7v - 13.8v (once hot) as reported on the scanguauge, and are nowhere near the often stated 14v+.
The diodes working as it's 13.1v - 13/2v without it, but these 14v+ numbers are well outside the range of my 150 VX Petrol, 2010 build.

I'm charging 1 x 105ag AGM dual battery in the boot, and 2 x 105ah AGM house batteries in the tug, with 160w solar to give them all a drink. We also have a couple of C-tek chargers off mains when power is available.

We head off on a 12 month lap in a few weeks so will see how robust the system is then, and look into DC-DC chargers if needed along the way.

Trev

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

Hello Warnsie

I've gone down the track of the Redarc DC/DC charger. You're on the money regarding changing alternator output according to load detected by the vehicle computer. The redarc charger I purchased has the prefix LV in its model number. This means "low voltage" allowing the charger to maintain its output of 40amps (I plan to service a large caravan battery bank) from input voltage from as low as 9v. This is to cater to reduced output of modern vehicle alternators. I had wanted to connect the charger to the negative terminal on the starter battery (along with the positive wire on its respective terminal). I was advised to stick to the manual and connect the charger negative lead to the vehicle chassis. The reason for this was that it could then read the electrical load being produced by the alternator and adjust its charging accordingly. The connection I had proposed would mean the charger would have been reading what was happening in the vehicle battery only which had not relation to the output of the alternator.

Although I didn't need the LV charger for my Prado (120 series 2003) its alternator is not one of the smart modern ones, I bought the charger for possible use with some more modern vehicle in the future.

Kel

The above does not apply to any Toyota model, only a cou[ple of vehicles use ECU controlled alternators such as the
Mazda BT50

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

Hi All

I keep seeing these figures, however my boosted alternator produces 13.7v - 13.8v (once hot) as reported on the scanguauge, and are nowhere near the often stated 14v+.
The diodes working as it's 13.1v - 13/2v without it, but these 14v+ numbers are well outside the range of my 150 VX Petrol, 2010 build.

I'm charging 1 x 105ag AGM dual battery in the boot, and 2 x 105ah AGM house batteries in the tug, with 160w solar to give them all a drink. We also have a couple of C-tek chargers off mains when power is available.

We head off on a 12 month lap in a few weeks so will see how robust the system is then, and look into DC-DC chargers if needed along the way.

Trev

Trev your vehicle would be an exception then, the only time I would expect to see such a low voltages with a booster fitted, would under very high ambient temperature conditions, in which case the alternator is doing exactly what it should do or if you have a faulty alternator.

[katrx7 Junior Member Find all posts View Profile Close katrx7]

no charge

Trev your vehicle would be an exception then, the only time I would expect to see such a low voltages with a booster fitted, would under very high ambient temperature conditions, in which case the alternator is doing exactly what it should do or if you have a faulty alternator.

gday guys, interesting forum, just wondering how I can determine voltage from alternator (not mech minded - just like getting the car dirty), as I think I might have a faulty alternator due to scratching noise when car moving, and the fact there is no charge going to 2nd batt??

the primary is at 13.8v when warm, car not on batt register's 12.5v

2month old century marine 730 now at 11.9v when engine running with no change after 3-4hrs driving

I run the projecta dual batt charger, 6mm copper, earth to chasis??

I just replaced my 3yr old batt thinking the batt was dead, but it turns out it could be something else??

any help would be greatly appreciated (remember your talking to a 12v dummy)

in a dilemma as were heading away soon and wont be able to have cold beers in the back