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

just4mrg
Explorer
Jun 01, 2016
Just wanted to thank you all for the education in charging systems. I now feel I have the knowledge and understanding of the relationship between the chassis and the starting battery. Thanks again !!
time2roll
Nomad
May 31, 2016
cgmartine wrote:
Can someone enlighten me? Does the BIRD do the same job as the Trik-L Start?
BIRD is bidirectional.

TLS is one direction and would be an addition to an isolator that already allows alternator to charge the house battery. TLS allows the converter to charge the chassis.
DiploStrat
Explorer
May 31, 2016
This is an excellent intelligent relay. https://www.bluesea.com/products/7620/ML-ACR_Automatic_Charging_Relay_-_12V_DC_500A

Has the advantages of high capacity and remote control. Blue Sea makes marine grade components.

There are, of course, many others one could use.
DrewE
Explorer II
May 31, 2016
cgmartine wrote:
Can someone enlighten me? Does the BIRD do the same job as the Trik-L Start?

Effectively, yes, though they are quite different gizmos. The BIRD is basically a fancy battery isolator/combiner based around a relay (or solenoid, if you prefer that term) with control electronics that will engage it whenever either side is at a charging voltage or when the emergency start switch is pressed. This means that it lets the alternator charge the house battery, and it lets the converter charge the engine battery.

The Trik-L-Start is more a DC powered low-amperage battery charger. When the house battery side is at a charge voltage, it lets up to five or so amps flow to the chassis battery side. Unlike a BIRD, it's current limited, but it only works in one direction on its own. Generally it's installed when there's some rather less fancy form of battery isolator in the RV (one that only serves to charge the house battery from the alternator).

With either case, the system will quite effectively keep the chassis battery charged when plugged into shore power.
Sfla2
Explorer
May 31, 2016
Bobbo wrote:
Sfla2 wrote:
slatsonly wrote:
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
Don't understand why u need a chassis bat charger, as its not being used at all when pluged in. u can leave u car sit for mo. , will still crank

I installed a Trik-L-Start because my chassis battery would run down every winter even though the RV was plugged in 24/7. When I killed the battery, after about 3 winters, I replaced it and installed the charger. The battery never ran down again. That was 6 years ago.
sorry abt what i said as u can see i'am in Fl not use to COLD winters also use rig all yr
cgmartine
Explorer
May 31, 2016
Can someone enlighten me? Does the BIRD do the same job as the Trik-L Start?
Bobbo
Explorer II
May 31, 2016
Sfla2 wrote:
slatsonly wrote:
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
Don't understand why u need a chassis bat charger, as its not being used at all when pluged in. u can leave u car sit for mo. , will still crank

I installed a Trik-L-Start because my chassis battery would run down every winter even though the RV was plugged in 24/7. When I killed the battery, after about 3 winters, I replaced it and installed the charger. The battery never ran down again. That was 6 years ago.
time2roll
Nomad
May 31, 2016
just4mrg wrote:
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?

1) maybe, plug in and check the chassis battery after 48 hours of no use. 13.2+ is being charged.

2) all motorhomes charge house and chassis batteries from the alternator.

Relay could be a BIRD to charge either way when a charging source is detected.

Could be a cut-off switch to remove parasitic loads from the house battery during storage.

Could be a boost start that temporarily connects the house to the chassis to start the main engine.
Sfla2
Explorer
May 31, 2016
slatsonly wrote:
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
Don't understand why u need a chassis bat charger, as its not being used at all when pluged in. u can leave u car sit for mo. , will still crank
DiploStrat
Explorer
May 30, 2016
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.

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