30 -- Aux Battery +
87 -- Starting battery +
85 (or 86) --- GROUND
86 (or 85) --- Attach to the blue wire that goes to the generator
warning lamp from the voltage regulator.
The blue wire goes from ground to 12+V when the generator spins up and
starts charging. It can be used for all kinds of neat relay stuff like
this charging circuit or a fuel cutoff solenoid or anything else you
don't want running while the motor isn't actually spinning.
Dave is correct, all this does is allow the aux battery to be charged
when the generator is putting out voltage. When the car is off the aux
battery is completely separate from the starting battery.
You will need to run new wiring from the aux battery to all of the
devices you want to run from it so that they are no longer connected to
the main fuse box at all.
When the car is off only those devices connected to the aux battery
will operate and they will only drain the aux battery.
When the key is ON or in ACC position but not running devices attached
to the main fuse box that require "key on" to operate will run from the
starting battery and aux devices will run from the aux battery.
With the car running and the generator warning light OFF (generator
doing it's job) the batteries will be connected together. Both will be
charging and the generator will provide power to both main and aux
circuits.
With your high draw circuits attached to the aux make sure you size the
wires accordingly to take advantage of the 75 amp rating on the relay
to allow the generator to power the circuits AND charge the battery if
you have devices running. I'd use at least a #8, possibly a #6 for (30)
and (87).
For most people who shut down the high draw circuits while driving the
75amp relay is overkill. A $4 30/40 amp relay from the nearest FLAPS
wired with #10 is plenty.
Diagram from GermanSupply on thesamba.com
http://www.thesamba.com/vw/forum/viewtopic.php?t=297050
G2
On Fri, 15 Mar 2013 11:50:05 -0500
"Bert Knupp" <[email protected]> wrote:
> Dave (and all),
>
> The new Bosch Batterietrennrelais is Nr. 0 332 002 156. It has a
> schematic printed on top -- but that doesn't tell me exactly what I
> need.
>
> Bert
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Dave C. Bolen
> Sent: Friday, March 15, 2013 10:34 AM
> To: Vintage VW Air-Cooled Discussion Group
> Subject: Re: [vintagvw] Battery isolation relay
>
> Bert,
>
> Part number for the new Bosch part please?
>
>
> Also, Let's think through your description of how this really works.
> From you explanation of the original relay wiring that has only 4
> terminals, I am not sure that it works the way you think it does.
>
> On the original:
>
> 51 is the feed providing charging power to either of the two
> batteries(or could it only be both at the same time!)
>
> 61 is ground when the generator is off(I am pretty sure)
> and provides a small positive comparison voltage
> when the car is charging(red light on or off comparison
> to the battery charging state).
> I am going to guess that when the charging system was "off" that you
> could pull the equipment battery all the way down and it would charge
> up after you restarted...andthat was about it.
>
> On the other hand...I have never owned one ofthese of a bus with the
> dual battery and don't know how it worked in a late model bus. My
> bet is that both batteries got the same charging current after the
> engine was started, but the equipment battery would give it's all and
> then that would be that till you restarted the car.
>
> Do you have a type2 manual with the same relay described in it?
> Seems kinda weird that VW(or Bosch) would use different devices to do
> the same thing for VW.
>
> Send the part number! Bet I can find a reference diagram.
>
> Cheers, dave
>
>
>
> On Fri, 15 Mar 2013, Bert Knupp wrote:
>
> >
> > Volks,
> >
> > I need some help. Various VW models over the years have used
> > dual-battery systems: campers, sound trucks, fire engines, and
> > police
> cars to name a few. The two batteries are connected via an isolation
> relay (in German it’s a “Batterie-Trennrelais”).
> > The idea is to permit both batteries to charge from the generator
> > or alternator, but to “uncouple” the #2 equipment battery when the
> > voltage
> drops below 11 volts, making sure that the #1 or starting battery
> doesn’t get pulled down by the equipment.
> > For example, in the police cars, it allowed the car to sit working
> > an accident with the blue light, flashers and radio running but the
> > engine off. If the available voltage dropped below 11 volts, the
> > starting
> battery would disconnect so the car could start when done.
> >
> > So I’m recreating the Copbug’s two-battery system. I’ve mounted
> > the #2 battery under the left rear seat and found a 75-amp Bosch
> > isolation relay on-line. The problem: the four terminals on the
> > new Bosch relay
> don’t match the four terminals on the VW factory bulletin for
> police-car wiring. I’m usually pretty good at logicking-through
> circuits, but I’m stumped here.
> >
> > The factory bulletin shows an isolation relay with four terminals:
> > 51, 61, 86 and 87.
> >
> > 61 comes from the 61 terminal on the voltage regulator. Skinny
> > wire.
> >
> > 51 comes from the B+ terminal on the voltage regulator. Fat wire.
> >
> > 86 goes out to the #1 (starting) battery (+). Fat wire.
> >
> > 87 goes out to the #2 (equipment) battery (+). Fat wire.
> >
> > The new isolation relay comes with four terminals also: 85-, 86+,
> > 30 and
> 87.
> >
> > The 30-to-87 circuit seems to be the switch that opens and closes.
> >
> > The 85-to-85 circuit seems to be the coil activation.
> >
> > The 87 and 51 terminals are high-amp screw terminals.
> >
> > The 85 and 86 terminals are low-amp Faston slip-on tabs.
> >
> > But I can’t figure what’s what. Can anybody help me? How do I
> > hook up
> the new relay to do the job?
> >
> > I’ve written to Bosch, but I won’t hold my breath. The last time I
> > asked them for help, the reply came 5 months later – and they said
> > they
> didn’t have information on the old equipment. Aargh!
> >
> > Bert Knupp in Music City USA
>
> --
> Visit the VintagVW archives at
> http://mail-archive.com/[email protected]
> ---
>
>
--
Visit the VintagVW archives at http://mail-archive.com/[email protected]
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