Charging house or chassis batteries

[TommyI1]

1. Does the generator charge both the house and chassis batteries? 2. Does the dashboard radio/DVD run off of the chassis or house batteries. My unit did not come with a separate inside stereo system; however, it does have a speaker selector switch.

[BehindBars]

Forest River makes a wide variety of RVs. Without knowing the year, RV type, and model of your RV, your questions would be difficult to answer accurately.

My in dash radio runs off the chassis 12 volt system. My generator charges both chassis and coach batteries as needed. As for your unknown model, I couldn’t say.

[bikendan]

Originally Posted by BehindBars

Forest River makes a wide variety of RVs. Without knowing the year, RV type, and model of your RV, your questions would be difficult to answer accurately.

My in dash radio runs off the chassis 12 volt system. My generator charges both chassis and coach batteries as needed. As for your unknown model, I couldn’t say.

The OP's profile says they own a 2014 Sunseeker 3010DS Motorhome.

[bubbles]

Originally Posted by TommyI1

1. Does the generator charge both the house and chassis batteries? 2. Does the dashboard radio/DVD run off of the chassis or house batteries. My unit did not come with a separate inside stereo system; however, it does have a speaker selector switch.

The generator has no charging capability; however, it does power the converter, which in turn provides battery charging capability just like shore power and if all your batteries are charged from shore power they should also be charged when on generator.

[TowPro]

depending on which Battery Isolation Module you have, the House charger probably will charge the Chassis battery, but there is logic involved. This is probably your answer.


and Sorry I don't know the answer to where the radio gets power.
Does the radio shut off if you turn off the coach battery?

[bubbles]

Originally Posted by TowPro

depending on which Battery Isolation Module you have, the House charger probably will charge the Chassis battery, but there is logic involved. This is probably your answer.


and Sorry I don't know the answer to where the radio gets power.
Does the radio shut off if you turn off the coach battery?

You analogy is between the engine alternator and/or converter charging not generator/shore power converter charging. The BIM logic may or may not allow cross charging but that logic is not dependent upon shore or generator power to the coach converter.

[ES_FR]

TommyI1,

We would be happy to assist you with this question regarding your Sunseeker. Please contact Kary Katzenberger in our Customer service department through the following personalized and direct link: http://www.forestriverinc.com/Direct...39005811722162.

This direct link is provided for your convenience in order that we may resolve your concerns as quickly as possible. We will strive to respond to you within 24 hours of receiving your correspondence.

Respectfully,
Forest River

[TowPro]

Originally Posted by bubbles

You analogy is between the engine alternator and/or converter charging not generator/shore power converter charging. The BIM logic may or may not allow cross charging but that logic is not dependent upon shore or generator power to the coach converter.

Thanks bubbles, I see my mistake in what I typed.


It should say:


(fixed) For Coach Charger to charge chassis battery:
Chassis battery must be below 12.6v
Coach battery must be above 13.3.
After 1 hour the BIM stops the charging and goes through this same voltage comparison above to see if further charging is necessary. (this prevents over charging of chassis battery)

[bubbles]

Originally Posted by TowPro

Thanks bubbles, I see my mistake in what I typed.


It should say:


(fixed) For Coach Charger to charge chassis battery:
Chassis battery must be below 12.6v
Coach battery must be above 13.3.
After 1 hour the BIM stops the charging and goes through this same voltage comparison above to see if further charging is necessary. (this prevents over charging of chassis battery)

Again, the BIM has nothing to do with the OP's question. The OP want's to know if all the batteries are charged from generator power. I don't know about his unit but if all batteries are charged from shore power then they are also charged from generator power (either one powering the converter with AC volts). The converter outputs charging power (DC volts) for the batteries when on shore/generator power. The BIM may or may hot allow charging of all batteries from when they are being charged by the converter. The converter doesn't care from where it is powered (shore/generator) for it to output charging voltage (DC volts) to batteries. The BIM looks at battery DC voltages only not any AC voltage. This is why the B.I.M. is Battery Isolation Manager. That nomenclature may not be the ideal one instead of maybe, Battery Interconnect Manager because that's what it does; it interconnects the batteries when certain battery conditions are met and then energizes. Isolation of batteries is accomplished when de-energized (static condition). It could go either way though.

[TowPro]

Don't get hostile here bubbles. My ignored user list is getting to big. Original question was 1. Does the generator charge both the house and chassis batteries? We all know the generator runs the DC charger to charge the battery. I was answering his question based on the results of what is in my 2019 Forester MH. The 2 batteries are separated by a BIM, which has logic as to when it allows one side to charge the other. So yes the BIM has everything to do with the generator charging the chassis battery.

[TowPro]

I based my reply on what I have learned from Precision Circuits.

The documentation shows step 5.
5. Charges
a. Coach Battery from Alternator
b. Chassis Battery from Coach Charger
I followed this up with a phone call to an engineer at Percision Circuits where I was told:

If one battery system is below 12.6v,
and the other battery system is above 13.3, it will connect the 2 systems so they can charge.
this election takes place every hour.
also in order for the Coach to charge the house you will need Positive applied to the IGN terminal as well as ground.
most of this accept the actual voltage is listed in that document.


The BIM is not a relay, it is a moving switch that does not consume power when connected or open (top of page 2 in document linked above)

12.6V is around 75-80% charged for an AGM, which should be enough charge to start the coach but not enough charge to hurt the batteries.

When I was learning how the system worked, first I called Forest River and was told that neither battery system could ever charge the other with an added note that went something like "don't you know you could over charge your batteries that way?"


Now I Assumed that same BIM was used on all Forest River Motor Home products, which might not be true.

[bubbles]

Originally Posted by TowPro

I based my reply on what I have learned from Precision Circuits.

The BIM is not a relay, it is a moving switch that does not consume power when connected or open (top of page 2 in document linked above)

Really. Continue reading the specifications under your reference. The relay is a latching type relay (switch) much like a battery disconnect relay wherein when switched the coil power switches to another position for activating in the opposite direction. All relay configurations do not require power to remain in a state and the BIM is one but it is a relay as stated in the specifications that uses a coil to activate (switch). Yes, not true; all FR motorhomes do not use a BIM. I'm done.

[TowPro]

Here is my reference. (right off the top of Page 2)
Operation:The Battery Isolation Manager opens and connects the two 5/16” copper terminals by means of a sliding contact. Each time BIM changes ON/OFF state, the contact instantly switches. The BIM remains in the ON or OFF State, without coil power.

were done here now.

[ScottBrownstein]

Originally Posted by bubbles

Really. Continue reading the specifications under your reference. The relay is a latching type relay (switch) much like a battery disconnect relay wherein when switched the coil power switches to another position for activating in the opposite direction. All relay configurations do not require power to remain in a state and the BIM is one but it is a relay as stated in the specifications that uses a coil to activate (switch). Yes, not true; all FR motorhomes do not use a BIM. I'm done.

when is a relay...a relay? Normally, in past designs, battery Isolation switches were solenoid switches that were powered continuously when batteries were parallelled. Frankly they are the most failure prone element of a BCC. They get hot when energized for days or weeks or months. Precision had a solution that would hit the coil with full 12 volts then back it off to something like 3.5 volts to hold and thereby reduce heating.

This latest revision from Precision has replaced the conventional isolation manager relay with a bi-directional switch that is powered to switch state and then stays in that state until powered again, like a battery disconnect Trombetta solenoid switch. In addition, the Precision BIM will parallel batteries when one is being charged and the other could use some charge. It will do it for a while and then drop back for a while and test again.

Neat, simple, powerful. It does decide if the converter charges the chassis or if the alternator charges the house. It does it all.

Is it a relay? Who cares. I have never seen a relay with a "sliding contact." Was a disconnect switch a relay...who knows? It works...and Precision is using it for all kinds of things...

[TowPro]

Its a great application.

but because of the built in safety mechanize designed in to the BIM, it will never 100% charge a battery across the BIM.


(again, from the documentation)

The BIM monitors the battery voltage of both the chassis and coach batteries over long periods of time. If it senses a charging voltage, it connects the two batteries together. If the charging system is drastically overburdened, the batteries will be isolated, however, if the BIM sees a long term charging of both batteries it will allow the batteries to remain connected and allow the charging system to do its job. Once the batteries have charged for one hour, the BIM will isolate the batteries to prevent overcharging, and will only reconnect the batteries for charging if one of the batteries drops to approximately 80% charge, and the other is being charged. This long term monitoring of the batteries prevents the annoying relay clicking that exists in simpler isolation modules today. The BIM does not guarantee 100% battery charge, but prevents harmful battery charge levels