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Old 10-13-2017, 05:31 PM   #41
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Default Re: Wiring idea for charging house batteries

Originally Posted by OldWest View Post
Why couldn't new switch just be on new wire (move new switch on schematic an inch over to right so nothing between K52 and DC-DC charger? Switch (on/off type, not a choose power source switch) would be at end of the new wire only, right before the DC-DC charger.

So whenever engine is on, there is always power to DC-DC charger (never have to worry about forgetting to switch over to engine power).

Problem with Reverse current?

Engine on, Switch OFF: DC-DC charger powered.by engine alternator.. No power coming from Meanwell converters. No power going to Meanwell converters.

Engine on, Switch on, ShorepowerGenerator on: Two sources of power from engine alternator and Meanwell converters. Does this work or do two sources of power into DC-DC charger create a problem?

Engine Off, Switch On, Shorepower/Generator: Power from Meanwell.Converters.

Engine on, Switch on: PROBLEM? Does power from engine alternator go to DC-DC charger AND in reverse direction into Meanwell converters so a PROBLEM?

Is this where the diode comes into play?

To respond to this, I think both items above you question, I also question.

I don't think running two source simultaneously into the dc-dc charger is a good idea.

And when engine on, switch on, I am not 100% sure either way with this, so was erring on the side of caution to avoid damaging converter.

So, it could work, but I feel there are bad "states" the switch could be in. With the either-or switch, this is avoided. Only one source connected at a time to charger, and in turn, house bank.

As is with wire from Kiss relay, same idea.
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Old 10-13-2017, 05:36 PM   #42
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Default Re: Wiring idea for charging house batteries

Side Notes:

1. Safety re Kissling Relay

Some other posters.here mentioned the high amps the Kissling Relay handles.



Also, one or more posters had loose connections at the Kissling Relay which caused severe scorching in the area.


2. Proper Installation Position of Kissling Relay

Search for OneManVan's posts on the Kissling Relay and how it works. Some wear and tear oe corrosion issues?


The existing vertical position combined with vehicle jostling was apparently not a good way to go.

Don't remember if there was a better installation (horizontal position).

Tapping/rapping with a wood handle was one quick remedy to dislodge stuck Kissling Relay.

Some possibly useful info and photos in this thread.


Note: Some posters may have tracked down a source for the Kissling Relay, but I remember as being a couple hundred dollars. May want to carry a spare or a spare manual switch replacement if relying on the Kissling Relay for more.than the Kerstner air conditioner.


3. Too Much for Engine Alternator: Discharged House Batteries/Sprinter Engine Air Conditioner--Anecdotal

When house batteries were discharged, the Kerstner air conditioner would not work off engine alternator.

But, if house batteries had been charged overnight, no problem with air conditioner.

One theory was that the engine alternator had too much load with both discharged house batteries and running air conditioner (or even making Kissling Relay work?).

Same issie with turning Kerstner AC on first, and then the Sprinter engine air conditioner.

This is all anecdotal and discussions with various Airstream techs.

(Similar story with discharged house batteries and same circuit microwave tripping circuit breaker--no problem with tripping if house batteries already charged.)

4. Harmonic Balancer, Alternator

But, for Sprinters with Sprinter rear air conditioners with extra pulley and belt in engine, harmonic balancer failure is more frequent (and maybe more frequent with Class C 3500 RVs).

And as to alternator, question is still open as to what type of duty cycles our Bosch alternator is designed to handle.


Like waiting for Christmas. What will you do? Lots of photos please.

Last edited by OldWest; 10-13-2017 at 05:59 PM. Reason: Add links.
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