Just need to understand this a little more.1) Plugged in to shore power, coach and house battery charging?2) Engine running, coach and house battery charging?If this is the case, what is this disconnect relay used for and when does this come into play to separate coach from house battery?Thanks in advance. Lot of expertise here.

My C has a disconnect (manually turns the house battery circuit off when parked for storage) and an isolator (automatically keeps the house electrical system from drawing any power out of the engine battery when the engine is not running).When plugged in, only my house battery charges.When the engine runs, it charges both the engine battery and the house batteries.Your system and number of batteries may vary.

research BIRD - Bidirectional Isolator Relay Delay...the emergency start toggle lets coach battery and/or coach genset connect to chassis batt when BIRD keeps the batts separated if one gets too low

A voltmeter will answer your questions, with much more reliability than any answers on here.

An excellent accessory that allows for charging of the chassis battery from the house batteries while hooked up to shore power or when running the generator is the Ultra Trik-L Start. Easy to install and not very expensive (<$50?). I am very pleased with my Trik-L Start purchase. Trik-L Start

2oldman wrote:A voltmeter will answer your questions, with much more reliability than any answers on here.True! That said, very few US RV's have good battery charging systems, suffering from several problems:-- Battery isolation is by a diode or a key controlled relay. The diode introduces an unacceptable voltage drop and a key controlled relay means that your shore power or solar power does not charge your starter/coach battery. The limitations of a key controlled relay lead to the installation of half measures like the AMP-L-START and the TRIK-L-START; they work, but they cure a problem that should not exist in the first place.-- The wiring between the starter and camper/house batteries is too small to permit a fast charge.-- The "converters" installed in many RV's do not perform a full absorb charge (they drop to float too fast) so even when plugged in, the camper batteries may not get a full charge.-- Solar chargers are nonexistent or too small and yet solar is almost indispensable to assure a full charge. You will note that I am quite passionate about this. There are lots of documents on my website that you may find useful. They, in turn, contain links for further reading.

Class C charging | Good Sam Community

slatsonly
Explorer
May 30, 2016
An excellent accessory that allows for charging of the chassis battery from the house batteries while hooked up to shore power or when running the generator is the Ultra Trik-L Start. Easy to install and not very expensive (<$50?).

I am very pleased with my Trik-L Start purchase. Trik-L Start
2oldman
Explorer II
May 30, 2016
A voltmeter will answer your questions, with much more reliability than any answers on here.
burlmart
Explorer
May 30, 2016
research BIRD - Bidirectional Isolator Relay Delay...the emergency start toggle lets coach battery and/or coach genset connect to chassis batt when BIRD keeps the batts separated if one gets too low
Tiger4x4RV
Nomad
May 30, 2016
My C has a disconnect (manually turns the house battery circuit off when parked for storage) and an isolator (automatically keeps the house electrical system from drawing any power out of the engine battery when the engine is not running).

When plugged in, only my house battery charges.

When the engine runs, it charges both the engine battery and the house batteries.

Your system and number of batteries may vary.

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