D3 voltage levels.

[drivesafe]

HI folks, I am looking for some feedback on Discovery 3 operating voltage levels.

If any of you have BM2 Bluetooth Battery Monitors fitted to your cranking batteries, when you got a spare moment, could you look back through those graphs and see what were the lowest and highest voltages registered.

The reason for my request is that I am about to upgrade the software in my DT90 and UST-175 isolators, to allow them to be used to charge lithium auxiliary batteries directly from the alternators in D3s.

This will mean no need for DC/DC device when you replace a lead acid battery auxiliary with a lithium auxiliary battery.

I will, in the next week or so, put full details up on AULRO’s Verandah section.

I already have a number of Defender customers who have swapped out their lead acid ( AGM and Wet Cell ) auxiliary batteries for lithium batteries.

If you can help with the operating voltage info, please post it up here.

Note any comments or requests will also be welcome.


Thanks, drivesafe.

[loanrangie]

Is the update to lower the output amps or just change the charge profile ?

[drivesafe]

Is the update to lower the output amps or just change the charge profile ?
Hi and No, I have been testing charging of lithium batteries with a non SMART alternator operation.

While D3s have a SMART alternator, so far I have not come across one that charged at less than 13.5v.

This makes them ideal for charging lithium batteries.

BUT, I am aware of D3s overseas, have charging voltages as high as 15.4v and this is an absolute No-No for lithium batteries.

The Traxide DT90 and new UST-175 isolators have an Over-voltage safety shut down of 15.1v, but this again is still too high.

As I posted above, I have a few customers with Defenders, charging lithium auxiliary batteries with no problems.

But D1s, D2s ( I am not sure about the D2a ) Series, Defenders and Pumas do not operate above 14.7v

I am considering adding a customer selectable Over-Voltage shut down of 14.7v, to be set when ever someone is charging a lithium auxiliary in a D3.

I would still like to know the maximum voltage reached with Australian D3s and more importantly, how long they operate at the highest voltages.

[DiscoDB]

Tim - I looked through all the trends that my BM2 has recorded, and from what I can see my ‘08 D3 always charges between 13.7-14.1V. Most of the time is probably around 13.8-13.9V.

I am more surprised I don’t see any higher voltages when charging (when the engine is running).

Edit: should note - I do have an 80W solar panel and this wired via the 15A fuse at the rear compartment but I am sure once the engine is running this contributes very little.

[BradC]

On a cold start when the temps are < 5C I often see charging setpoints on the GAP of > 15V, but in practice I've never seen much above 14V.

[scarry]

I can see my ‘08 D3 always charges between 13.7-14.1V. Most of the time is probably around 13.8-13.9V.

As did my D4 2.7,which i believe had a similar system and no smart alternator.

The 3.0L D4 was different.

[loanrangie]

I have seen 14.5V on my D3 but generally high 13 to low 14's.

[drivesafe]

As did my D4 2.7,which i believe had a similar system and no smart alternator.

The 3.0L D4 was different.
Hi Scarry and the D3 and 2.7 D4 do have a version of a SMART alternator.

The primary difference is that the D3/2.7 D4 voltages never go down below about 13.5.

But unlike Variable voltage alternators, as found in Toyotas and the likes, where they do not monitor the cranking battery, D3s and 2.7 D4s do actually both monitor the cranking battery and adjust the charge algorithms to best suit the charge needed based on the condition of the cranking battery.

[Narangga]

I have seen 14.5V on my D3 but generally high 13 to low 14's.

Tim due to the issues I've had over the last couple of weeks the BM2 currently does not have much to offer. I too have had 14.5V on the live readings on the Nanocom (used while on longer trips) and regularly the same sort of consistency like loanrangie & DiscoDB. HTH.

[RANDLOVER]

Can't we just get this info from China? Bluetooth Battery Monitors That Also Monitor Your Position, Without Asking | Hackaday (https://hackaday.com/2023/06/27/bluetooth-battery-monitors-that-also-monitor-your-position-without-asking/)

[DiscoDB]

Out of interest, went back over 3 years of data - which picked up the lockdown periods.

This is prior to adding solar, but during the lockdowns my battery voltage regularly dropped below 12v as the car was parked up for many many weeks at a time.

Even on a cold morning start with the battery below 12v (as low as 11.7-11.8v), the BM2 only logged a peak of 14.1-14.2v after restarting. Actual peak may be higher but this is not seen on the daily trend graphs.

https://uploads.tapatalk-cdn.com/20230719/64f388810c5f75d26c6703df716dd68a.jpg

The graph above was the day before the start of a 2 week lockdown. I did a trip out of Melbourne but had to be back that evening when the lockdown started. Was just a typical short snap lockdown that lasted many weeks.

From what I have read, the only real time the generator will ramp up the voltage is for very low temperature operation where I have seen reports of &gt;15v being observed.

So having a high voltage cut off setting for cold climate use to suit a lithium auxiliary battery sounds like a great idea.

And no - the battery did not survive the lockdowns (not quite true - it was replaced but still does light duties in the garage).

Edit: I should add - the example above does not show the auxiliary battery which was fully isolated with the engine off, but holding 12.9v at the time even after extended periods of no use. As soon as the USI-160 did energise, I am sure there would have been some good current flow from the auxiliary to the cranking battery.

[shack]

Hope this helps.

Running 75 litre dual zone fridge freezer which is responsible for the discharge.https://uploads.tapatalk-cdn.com/20230721/1cfc5cb5cd8eaf39633cca713a4f7d91.jpghttps://uploads.tapatalk-cdn.com/20230721/cdcb01fb7a6cf828ea2efbca5a1ae9ed.jpghttps://uploads.tapatalk-cdn.com/20230721/07a36cc360ffaf0db86ca56493ad5667.jpg

[drivesafe]

Hi Shack and thanks for those graphs.

Where are you located?

And is this a D3 or D4?

[simonmelb]

Hi Tim,

Confirming D2a max voltage I have seen is 14.61V.

This is measured using my Victron MPPT 75/15 solar controller connected to my AGM battery in the rear of my D2a. It has a new OEM Denso alternator which feeds the rear battery via an SC80 and fully thick cable as per your recommended setup.


Hi and No, I have been testing charging of lithium batteries with a non SMART alternator operation.

While D3s have a SMART alternator, so far I have not come across one that charged at less than 13.5v.

This makes them ideal for charging lithium batteries.

BUT, I am aware of D3s overseas, have charging voltages as high as 15.4v and this is an absolute No-No for lithium batteries.

The Traxide DT90 and new UST-175 isolators have an Over-voltage safety shut down of 15.1v, but this again is still too high.

As I posted above, I have a few customers with Defenders, charging lithium auxiliary batteries with no problems.

But D1s, D2s ( I am not sure about the D2a ) Series, Defenders and Pumas do not operate above 14.7v

I am considering adding a customer selectable Over-Voltage shut down of 14.7v, to be set when ever someone is charging a lithium auxiliary in a D3.

I would still like to know the maximum voltage reached with Australian D3s and more importantly, how long they operate at the highest voltages.

[shack]

Hi Shack and thanks for those graphs.

Where are you located?

And is this a D3 or D4?D3, and I think it was at or near Innamincka.

[drivesafe]

D3, and I think it was at or near Innamincka.
Thanks and do you remember the outside temperature, in the morning?

[shack]

Thanks and do you remember the outside temperature, in the morning?Wasn't terribly cold, maybe 3-5°.

[drivesafe]

Wasn't terribly cold, maybe 3-5°.
Thanks again Shack, and between the low temperature and the fact you were running your fridge 24/7, the SMART alternator operation is well within what I would expect.

That is a great bit of info Shack and it confirms the need for an over-voltage shutdown function to be added to my isolators, allowing them to be used safely when charging a lithium auxiliary battery.

Thanks to everyone for your info and it will be of great assistance while doing my latest upgrade.

Nothing like first-hand info and great feedback.

Only on AULRO!

[SeanC]

186301

2008 TDV6