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Blugnomad
15-03-2016, 12:59 PM
Hi,

Does the 2015 Amarok charge at 14.2V or does it drop the charging voltage after the first few minutes?

I'm wondering if I need to fit a DC-Dc charger for the auxiliary battery?

Cheers,

Tony

h100vw
15-03-2016, 01:19 PM
Hi,

Does the 2015 Amarok charge at 14.2V or does it drop the charging voltage after the first few minutes?

I'm wondering if I need to fit a DC-Dc charger for the auxiliary battery?

Cheers,

Tony

The voltage will likely drop as the current output falls. So highest voltage just after engine start.

I would have thought the alternator would be plenty able to charge a second battery. Especially if you don't run it flat first.

Gavin

Blugnomad
15-03-2016, 02:22 PM
Hi Gavin,

A lot of new vehicles drop to 13.2V to save fuel. Some don't, they stay at 14.0 to 14.2V, I'm wondering which group the Amarok is in.

Tony

h100vw
15-03-2016, 05:35 PM
Hi Gavin,

A lot of new vehicles drop to 13.2V to save fuel. Some don't, they stay at 14.0 to 14.2V, I'm wondering which group the Amarok is in.

Tony

You better link me up, I haven't heard this before.

Gavin

Blugnomad
20-03-2016, 12:12 PM
Hi Gavin,

All the 4wd Toyotas ( google diode mod), Nissans (green wire mod), practically anything since about 2010 where the ECM controls the alternator.

Improves the emissions and the advertised fuel consumption and the sales of battery boosters for caravans and auxilary car batteries.

Cheers,

Tony

h100vw
20-03-2016, 04:11 PM
Hi Gavin,

All the 4wd Toyotas ( google diode mod), Nissans (green wire mod), practically anything since about 2010 where the ECM controls the alternator.

Improves the emissions and the advertised fuel consumption and the sales of battery boosters for caravans and auxilary car batteries.

Cheers,

Tony

Never heard of this on a VW but I'll wait to be corrected.

Gavin

Transporter
20-03-2016, 05:02 PM
Hi,

Does the 2015 Amarok charge at 14.2V or does it drop the charging voltage after the first few minutes?

I'm wondering if I need to fit a DC-Dc charger for the auxiliary battery?

Cheers,

Tony

Just connect the voltmeter to the fully charged battery (with the bonnet up), start the engine and observe the voltage.

Blugnomad
28-03-2016, 08:12 PM
Since my previous posts I've done a long enough trip to see that the voltage settles to about 13.8V. Not enough to fully charge an auxiliary battery. Now I need to decide what boost is necessary, as it's almost enough.

Cheers,

Tony

Transporter
29-03-2016, 08:43 AM
Why you don't use 12V to 12V charger? It would greatly extend the life of the second battery. Projects and RedArc are great and even allows you to connect a solar panel.

Blugnomad
08-04-2016, 06:15 PM
That's the next step, I've got a low powered DC-DC but it appears I need at least a 20A.

As Abba sang. "Money, money, money...."

Sherwy
13-07-2018, 11:50 PM
Does anyone know if it's possible to put a smart regulator in the standard alternator?

I'm told the current V6 Amaroks have a 95 A/h AGM battery. As Blugnomad says 13.8 isn't enough to fully charge an AGM.

Cheers,

Sherwy.

Transporter
29-07-2018, 09:26 AM
Does anyone know if it's possible to put a smart regulator in the standard alternator?

I'm told the current V6 Amaroks have a 95 A/h AGM battery. As Blugnomad says 13.8 isn't enough to fully charge an AGM.

Cheers,

Sherwy.

From my experience and I have the AGM battery in mine (2.0TDI), it charges the battery just fine. When the battery is discharged the voltage goes well over 14V even on V6 Amarok and as the battery is close to fully charged the voltage drops. When you see the 13.8V, it’s float charge and sure enough even for the AGM batteries. You don’t want them to be charged at 14.4V at high temperature environment, like under the bonnet. As far as charging a second battery away from under the bonnet, when you use DC-DC charger it will charge even when your battery is at any voltage from approximately 11V.

Sherwy
15-06-2019, 10:11 PM
Hi gents,

I bought a little cigarette lighter volt and temp gauge thingy a while back and have been observing it. It was only a cheap ebay job but there seems to be very little difference between my multi-meter at the battery and this thing so its good enough to get a rough idea of whats going on.

Before start up it always seems to be around the 12.9 mark, but as soon as you hit the unlock button on the key those pesky auto headlights kick in and drain it down to 12.4. I'm sure there's a few other things that get turned on too, I can hear really feint whirring sound if its really quiet. A few second after starting it jumps up to 14 or 14.2 but rarely any higher than that. Depending on the state of charge of the battery it will take anywhere from 10 to 30 minutes before it drops down to 13.8. After running running my camp fridge for 8 hours one day it took about an hour to drop to 13.8. I've never seen it go below 13.8 with the engine running.

So you may need be getting absolute full charge but you would be getting very close, at least 90%. As Transporter says, you don't want the really high absorption voltages if the temp of the battery is up. I am going to run a Lifeline AGM as my auxiliary battery, their specs say 14.4v for absorption charge at 20 degrees and 14.2v at 25 degrees, by the time you get to 50 degrees its 13.8v. For charging I am going to keep it simple and hook it up with one of Traxides' beautiful isolators. USI-160 | TRAXIDE - RV | Traxide - RV (http://www.traxide.com.au/isolators/usi-160.html)
These are one of the best and most full featured isolators on the market and made right here in Oz on the Gold coast. They are smart enough to allow you to pull some charge out of the the start battery before isolating it so you have a significant gain in capacity there. Certainly a hell of a lot more than you would gain from a $600+ DCDC charger getting that last 10% in!

If you are going to install a recovery winch but also want increased capacity for fridges etc then these things really do stand alone as they will detect winching loads and close circuit so the auxiliary battery can help with the winch loads. They monitor both batteries too so if you plug your solar panel or charger into your auxilliary battery it will detect this and close circuit so both batteries get charged. Pretty good for less than 200$!

Cheers,

Sherwy.