Community Forums

Training Wheels · 03-31-2018, 07:21 PM

On my son’s 2014 Newmar Baystar 3215, the chassis battery would not stay lit. I researched and replaced the Battery Isolation Manager (BIM). (FYI: Per the owner’s guide, there is no BIRD on this coach. Newmar quit using that Intellitec product after 2003). The sense board over the door shows good voltage now on chassis and coach; but that’s when plugged in. After he takes it on the road some, we’ll see.

My question: I’m going to replace the OE G24 house batteries w 2 6V AGM Lifeline 6CTs. In series, they are rated at 300Ah, which at 50% SOC, should give 150Ah without recharge. My concern is the 100A rated BIM. The chassis battery will still be G24. While the functionality should work with just a switch out plug-and-play, I’m thinking the current (Amps) difference may fry the BIM.

If you think this is a problem, what alternative isolation-combining system can I use? If you think 12V is 12V and the BIM won’t care, why so?

I intend to contact the BIM’s mfgr, Precision Systems, and see what they say; but I value your opinions based on experience having changed batteries in a Newmar after they quit the BIRD and went with the BIM.

(007, are you out there?)

Jerry

twinboat · 03-31-2018, 07:50 PM

The BIM solenoid only carries the charging amps from the engine battery to the house batteries.

I don't expect that your alternator will send more then 100 amps to the house batteries, while charging from 50% capacity.

Remember, when the BIM closes the solenoid, the alternator output is being regulated by the combined voltage of both the chassis and house battery.

Your house loads and inverter draw do not go thru the BIM solenoid.

Training Wheels · 03-31-2018, 08:06 PM

Don’t understand 3d paragraph.

Jerry

Training Wheels · 03-31-2018, 08:09 PM

Following up:

There’s 2 voltages w rv batteries: The charging voltage, which is usually 14+. There’s also the output which is 12.7 downwards. Which is applicable to the BIM?

Jerry

Training Wheels · 03-31-2018, 08:12 PM

Related:

Anyone know the alternator output on a 2014 F53 V10?

Jerry

Luv2go · 03-31-2018, 09:19 PM

Quote:

Originally Posted by Training Wheels

Related:

Anyone know the alternator output on a 2014 F53 V10?

Jerry

It's 175A according to this brochure.

We had issues with the relay that the BIRD uses after we installed a 2500W inverter. The issue was that when the inverter ran the microwave with the engine running it would try to draw 150A from the alternator and the voltage drop would cause the relay to open, then the voltage would go back up and the relay would close and doing this repeatedly ruined the contacts. Changing the relay to a heavy duty version resolved the issue (the other solution, telling tell DW to not run the microwave while the engine was running, went over like a lead balloon

).

My opinion is you will not have a problem with the BIM 225A relay you have in your coach, it looks a lot like the heavy duty one I used. Here's a picture of the BIM from the Newmar parts website:

FatChance · 03-31-2018, 09:37 PM

The BIRD system extended beyond 2003. Our 2004 MADP has a BIRD.

twinboat · 04-01-2018, 03:50 AM

Quote:

Originally Posted by Training Wheels

Don’t understand 3d paragraph.

Jerry

The alternator and BIM are sensing the chassis battery voltage when the engine is running.

After starting the engine and when the chassis battery reachs 13.2 volts, the BIM connects the house battery to the chassis battery, just like a jumper cable.

If the house batteries are at 50% charge, they are at 12.02 volts. When the BIM closes, current is going from chassis battery to house battery. The voltage drop will be somewhere between 12.02 and 13.4. Your alternator does not sense 12.02 volts, so it will likely never sends more then 100 amps thru the BIM solenoid.

If the house batteries voltage were so low that they did drag the chassis battery below 12 ish volts, the BIM is designed to open the connection. That is so your chassis can maintain the voltage needed for the onboard engine systems and lights. It also protects the alternator from overloading and overheating.

twinboat · 04-01-2018, 03:59 AM

Quote:

Originally Posted by Training Wheels

Following up:

There’s 2 voltages w rv batteries: The charging voltage, which is usually 14+. There’s also the output which is 12.7 downwards. Which is applicable to the BIM?

Jerry

There is a range of voltages on RV batteries, from less then 12 to 14.6.

A battery at 12.0 volts or 50% state of charge, will charge up to 14.6. How long that takes depends on how many amps are pushed into them.

If the BIM solenoid is closed, the voltage on each side will be almost exactly the same, as long as its above 13.4 volts.

If one side is lower then 13.4 volts under normal conditions, the solenoid, or BIM control, is not working.

RetiredBob · 04-01-2018, 10:23 AM

My 2011 Canyon Star has a BIRD.

Luv2go · 04-01-2018, 12:58 PM

Quote:

Originally Posted by FatChance

The BIRD system extended beyond 2003. Our 2004 MADP has a BIRD.

Quote:

Originally Posted by RetiredBob

My 2011 Canyon Star has a BIRD.

Just to clarify, at least on BayStar Newmar switched to the BIM in 2014, a quick check on their parts website (Scroll to the bottom and click the "Parts Inquiry" link) confirms that 2013 was the last year they used the BIRD on the BayStar.