Anyone Use An Adjustable Voltage Regulator?

VeeDubDaySpa · Posted: Sun Sep 28, 2014 9:17 pm Post subject:

PDX-

I just ordered this as I'm going to be running an AGM house battery- just to clarify, you set your voltage to 14.5 (measured at batteries?) then you drive with the lights and heater on to drop the main battery voltage down to 14.2? That way your AGM is still receiving the higher 14.5 volts?

still working well?

Thanks!
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North American Hightop Installer/Distributor
Current stock (5)
Hot Water Systems
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90 Syncro NAHT Vanagon RHINO
86 "Syncro" Van DIAMOND
87 Syncro Hightop WestyCamper ROCKY (for sale soon)
79 bay window OLIVER

uncommonvw · Posted: Thu Oct 09, 2014 7:17 pm Post subject:

I just installed an adjustable voltage regulator from the davebarton.com website.

I'm curious as to the voltage I should set it to while at idle? I currently have it set at 14.2V at idle. It jumps to 15.5V at 3000 RPM with no load on the electrical system. Am I supplying too much voltage off idle? I don't want to cook my batteries.

I'm running a stock type starting battery and a deep cycle marine auxiliary battery using the GoWesty isolator kit (which I've been told to replace with a SurePower or Yandina).

The alternator light stays dimly lit while at idle which I had hoped the new regulator would fix. I will check the blue exciter circuit and grounds next.

Rodknock · Posted: Fri Oct 10, 2014 7:47 am Post subject:

I believe I have my adj. VR set at about 14.5 at the starting battery terminals, and it shows about 14.2 at the auxillary battery, so I don't think you have it set too high. I am using the GW kit like yours (works fine BTW) and a marine deep cycle.

uncommonvw · Posted: Fri Oct 10, 2014 8:25 am Post subject:

I just re-checked the voltage at different locations. I would like to ensure that I'm not over charging my battery.

At idle 850-900 RPM

Starting battery 14.12V
Aux. Battery 13.95-14.06V
Alternator 14.21V

At 3000 RPM (no electrical load) these are the numbers that concern me

Starting battery 16.6V
Aux. Battery 15.82V
Alternator 16.98V

Am I worried over nothing here.

Obviously the alternator is making enough voltage to charge the battery. However, the alternator light is still dimly lit at idle. Think

VeeDubDaySpa · Posted: Sat Oct 11, 2014 4:36 am Post subject:

Popular vendors sell an Alternator Charge Initiation Kit, for $25 it's a plug and play harness to fix the light being on at start up. I bought one but engine is out so haven't got to test it yet...

I'm no expert on DC power but those numbers seem way too high. Here is something found using a google search:
---------------------------
Charging

The charging voltage is very important. Is the voltage too high (over 14.4 V) water will evaporate, explosive gases will develop, and the battery gets warm or even hot. The battery gets destroyed.

- The correct charging voltage is 13.8 V – 14.4 V and the charging time should be 10 – 16
hours.
- The typical (daily) charging should be 14.2 V - 14.4 V
- During charging the battery must never get hot.
- Continuous-preservation charging: 13.4 V for gelled electrolyte and 13.8 V for flooded cells

After full charge the terminal voltage will drop quickly to 13.2 V and then slowly to 12.6 V.
-----------------------------

Perhaps set the regulator to the desired voltage at the 3000 rpm phase?
_________________
North American Hightop Installer/Distributor
Current stock (5)
Hot Water Systems
_______________________________________
90 Syncro NAHT Vanagon RHINO
86 "Syncro" Van DIAMOND
87 Syncro Hightop WestyCamper ROCKY (for sale soon)
79 bay window OLIVER

uncommonvw · Posted: Sat Oct 11, 2014 6:23 am Post subject:

Update:

Turns out there was something wrong with my alternator.

I swapped out the alternator with another one and was getting a steady 13.8V at idle with the stock regulator.

Put in the adjustable regulator and was getting 14.2V at idle and 14.5V at 3000 RPM.

Thanks to Jay Brown (thatvwbusguy) and Dave Barton (www.davebarton.com) for explaining what was happening.

madspaniard · Posted: Sat Oct 11, 2014 9:10 am Post subject:

VeeDubDaySpa · Posted: Sat Oct 11, 2014 10:27 am Post subject:

uncommonvw · Posted: Sat Oct 11, 2014 6:14 pm Post subject:

TommyBoyGomes · Posted: Sun Oct 19, 2014 8:23 pm Post subject:

For those of you who have been using the adjustable voltage regulator now for some time, have you seen any negative long term effects anywhere in the electrical system? Thanks.
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1969 Squareback, 1776cc
1990 Vanagon Multivan

vanonimous · Posted: Mon Nov 10, 2014 11:16 am Post subject:

I've used adjustable regulators on other then Vanagon (still Bosch) systems for years now and my experience is I am usually just counteracting a symptom and not addressing the actual problem. Like for example a battery that won't take or hold full charge or to high a resistance on slip rings, failed diode on the bridge, high resistance wiring and such. Still it is OK as temporary solution but on a perfect running charging system it shouldn’t be needed.
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If happiness is being a mechanic, owning a Vanagon is nirvana.

Lighting upgrades: https://www.thesamba.com/vw/forum/viewtopic.php?t=578291

VeeDubDaySpa · Posted: Tue Nov 11, 2014 1:31 am Post subject:

noganav · Posted: Tue Nov 11, 2014 1:45 pm Post subject:

I just installed an adjustable voltage regulator, then had an electrical fire at the main terminal of my alternator.

Coincidence? Sort of. I probably only needed the adjustable because I was losing volts to a poor wire in the first place. With some new 6AWG to the starter, I didn't feel the need to put the adjustable back on the new alternator.

I'd say if your system is losing so many volts that you need to worry, look at the condition of the wires first and mess with the alternator second.

vanonimous · Posted: Sun Nov 16, 2014 12:31 pm Post subject:

Classic example of counteracting a symptom instead of addressing the problem. I wish I could have my doctor see that perspective.
-> KevbOliver I have never used AGM in parallel with lead acid batteries but they should have the same charging requirements, no? I use standalone AGMs on my bikes and they seem to work great.
Where does your output voltage cut off? Go past 14.5VDC and you'll be boiling off H2O molecules out of a vented lead acid battery it will probably not be good for it.
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If happiness is being a mechanic, owning a Vanagon is nirvana.

Lighting upgrades: https://www.thesamba.com/vw/forum/viewtopic.php?t=578291

TommyBoyGomes · Posted: Sun Nov 23, 2014 6:07 pm Post subject:

Just wanted to provide a before and after report of my adjustable regulator install for the archives:

I used the voltage regulator module from aircooled.net, which has alot of nylon/plastic parts instead of the original metal parts that come with the alternator's regulator. It's also physically smaller than the original metal one and there's about a 1/2" gap between the body of alternator and the perimeter of the aircooled.net regulator (vs. about a 1/4" gap on the original one). I'm hoping this isn't an issue?

I have the gowesty auxiliary battery set-up in my van, but everything else including the wiring is all stock VW. Here are the voltages I was getting with each setup:

With original Bosch voltage regulator (non-adjustable):
Main Battery @ idle = 13.99V
Main Battery @ 3000 rpm = 14.01V
Main Battery @ 4000 rpm = 14.02V
Aux Battery @ idle = 13.61V
Aux Battery @ 3000 rpm = 13.66V
Aux Battery @ 4000 rpm = 13.66V

With the adjustable voltage regulator installed (after I adjusted the setting a little bit upwards to get 14.5V at the main battery):
Main Battery @ idle = 14.48V
Main Battery @ 3000 rpm = 14.49V
Main Battery @ 4000 rpm = 14.5V
Aux Battery @ idle = 14.0V
Aux Battery @ 3000 rpm = 14.01V
Aux Battery @ 4000 rpm = 14.01V

I was a little surprised that the voltage didn't change much when the engine was rev'd. Is this normal?

So all in all this adjustable regulator increased the charging voltage batteries by about .4V. While I know that my AGM aux battery would also like to see 14.5-14.7V during charging instead of 14.0V, that's a different project for a different day.
_________________
1969 Squareback, 1776cc
1990 Vanagon Multivan


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Anyone Use An Adjustable Voltage Regulator?
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