Disabling BIRD-BCC in a Lithium Upgrade

[anand.s]

Hi All -

Long time lurker but first post here on the advice of a fellow member on the Beaver Ambassador Club forum.

I'm in the midst of a Lithium upgrades on a 2007 Beaver Marquis that has the Bird-BCC board;  I'm trying to figure out if there is a hack to save the Boost function / keep the Big Boy connected and disable the functions that close the solenoid.    One idea was to disconnect pin 2 (red wire) and pin 3 (white/orange) from the 8pin Molex (House 12v and 12v Switched ignition) but the engine doesn't start after doing so.    It seems the board may get its power from the red wire.   I'm not sure what would happen if I removed only switched ignition and whether a threshold voltage reading on the house batteries would still close the solenoid.

I'm told there are folks on this form that likely understand the BIRD-BCC better than anyone else on the planet, was hoping to get some sage advice.   I still need to disable the Big Boy no matter what - so best way to do that is also appreciated (current plan is to pull the trigger wires), not sure if I can just pull the 7.5 BIRD fuse on the board.

I'm setting up an alternative charging mechanism - an ignition triggered 60A DC-DC that charges the House bank (1200AH of LifePO4) combined with an ignition-disabled AMP-L-START to ensure charging of Chassis from House on shore and solar.   

Thanks in advance for any advice, and generally for the wealth of information in this community.  Hope to be as useful to others as so many of you have been to me.

Best,

Anand

 

 

[Mark B]

If I'm not mistaken the boost function has an input to the BIRD but is not dependent on it. So if you remove the BIRD like I did the wire continues on to the connection relay that joins the start and house batteries together.

[Mark Holt]

Mark B, this is what I have been told by folks that are doing my Lithium install. The DC-DC Victron basically replaces the bird to limit the amount of AMPs drawn from the alternator. Not an expert but this is what I’m told by installers and Battle Born CS folks.

[anand.s]

Thanks for the comments here, not sure I can remove the BIRD as it is part of the circuit board motley in the rear run box, and the BIRD-BCC board in the 2007 + years also controls the salesman switch.   

 

[Mark Holt]

anand.s, 

Replacing the bird was bad statement. I understood it to be that is works in line with the bird for lack of a better term to limit the AMP draw from the alternator that the Lithium will take in order to protect the alternator from damage from overheating. The Victron product has a 30 AMP limiter. Sterling also has this product in 30,50 and i think 60AMP limit. There are many folks on this forum that are better versed than I. I look forward to their input. From what I understand the most compelling issue when going to Lithium house batts that have alternator charging is to protect the alternator from overheating due to lithium demand. 

[anand.s]

Mark,

You may have just solved my problem, and I might owe you a beverage of your choice!   If I hear your correctly, the DC-DC install does not require me to disable the BIRD.    BIRD combines battery banks, in the case of providing alternator charge to house, when the voltage of the chassis batts are high enough and the house batteries are low - thereby creating a situation where Lithium would draw more current than the alternator should provide in its duty cycle (because Lithium does not naturally limit charging current, and at 1200AH would be very hungry).

SO, this gets me thinking:  If the DC-DC is on, the BIRD would never find the need to engage because a limited current pathway is providing charge (and thereby voltage level that is above the threshold for the BIRD to close the Big Boy)?

Do I not need to disable the Big Boy at all with a DC-DC scenario?

I've installed a 60A DC-DC from chassis > house, and using an AMP-L-START as a 15A DC-DC from House to Chassis (disabled with ignition on) - this way solar and shore also trickle charge the chassis (the BIRD should not engage)

Thanks!

Anand

 

 

[Mark B]

Here is the picture of my bay. Victron DC-DC and the AmpL Start.

[Windsornut]

I added lithium batts. and solar on top to my 02 Windsor.  In the process I bought a LIBIM Lithium batt. mgr.   The great big black relay (1/2 soda can size) was replaced on mine with the LIBIM, along with 1 or 2 other pieces.  LIBIM main job is to direct alternator back and forth between house and chassis batts.  Alternator charging big bank of lithium batts. can burn up from over work.  If you're interested in this idea, the Battle Born batt. guys can help and also Chris can help on these older coaches at  M-M rv electronics dot com  I think.  I think he probably has any parts you may need as well.  The changeover can get a little complicated.  I did a new Magnum inverter as well.  MFFT more food for thought.

[Mark Holt]

20 minutes ago, Windsornut said:

I added lithium batts. and solar on top to my 02 Windsor.  In the process I bought a LIBIM Lithium batt. mgr.   The great big black relay (1/2 soda can size) was replaced on mine with the LIBIM, along with 1 or 2 other pieces.  LIBIM main job is to direct alternator back and forth between house and chassis batts.  Alternator charging big bank of lithium batts. can burn up from over work.  If you're interested in this idea, the Battle Born batt. guys can help and also Chris can help on these older coaches at  M-M rv electronics dot com  I think.  I think he probably has any parts you may need as well.  The changeover can get a little complicated.  I did a new Magnum inverter as well.  MFFT more food for thought.

 

Greg, the libim225 is a solar battery manager. Which is needed when adding solar to the system. In my case I’m not having solar added. It is the other additional pieces you mentioned that Battle Born advised without the libim required for solar. Battle Born advise me that simply changing from lead to lithium does not require the battery management system to change from the BigBoy.

[anand.s]

Thanks guys - I have an LiBIM but I think you also have to bypass the BIRD-BCC which is more of a mess than I'd like to do and I'd lose other functions.  Hence the DC-DC/AMP-L-START.   Mark, have you left the BIRD and Big Boy operational as-is without issue?   My setup works a lot like yours but I was under the impression that the solenoid will still engage which connects the two banks outside of the two DC-DCs.  

Thanks for the lead to Chris at M&M - will try to call them tomorrow.

Anand

Edited March 23, 2022 by anand.s
add pics

[Mark B]

My coach doesn’t have a “Big Boy” but it does have a similar relay that connects the two battery banks. The only thing I have left to operate that relay is the booster button on the dash. I removed the old trickle charger and the BIRD. Mine looks way less complicated! LOL

[Bob Blackmon]

If you only want to remove the BIRD's (PB6 board) ability to combine the batteries and retain the Big Boys ability to combine for boost only, no problem. Terminate both control wires to the Big Boy. Run unswitched 12VDC + to one side of the Big Boy. Cut the wire, in 2004 it was org, in p4 of J1 on PB6 and go to the other terminal on the Big Boy. PB6 is mid level on the right side and has 2 yellow buttons and 2 fuses. The board will retain all other functions. 15 minute solution to your problem.

Rear Run Box.pdf

Edited March 23, 2022 by Bob Blackmon

[anand.s]

@Bob Blackmon

Thanks for this - elegant solution.   On the 2007 the boost is P4 on J2, but this solves my problem.   12V House (fused) to one side of the Big Boy, and remove P4 and connect it to the other.  Maintains the board, the boost switch, and disables the BIRD closing the Big Boy.

Will report back when I try it later this week.

Thanks

Anand

[Bob Blackmon]

46 minutes ago, anand.s said:

@Bob Blackmon

Thanks for this - elegant solution.   On the 2007 the boost is P4 on J2, but this solves my problem.   12V House (fused) to one side of the Big Boy, and remove P4 and connect it to the other.  Maintains the board, the boost switch, and disables the BIRD closing the Big Boy.

Will report back when I try it later this week.

Thanks

Anand

Confirm it is ground from the switch

[vito.a]

Many Monaco/Beaver owners are replacing the Intellitec battery isolation system with a Blue Sea ML-ACR.  The Blue Sea system is guaranteed for life and gives you total control over joining the chassis and house battery systems.  

Link to install thread:  https://www.irv2.com/forums/f115/replace-big-boy-with-blue-sea-ml-acr-468617.html

I assume your coach has the Leece-Neville 270 amp alternator.  You are short changing yourself with only a 60 amp DC- DC charger when you have 270 amps available.  

I realize many of the lithium experts say you must protect your alternator, but they assume you have a standard automotive alternator.  Some of the large Monaco coach owners are successfully using lithium batteries with the big Leece-Neville alternators.  They are just insuring the battery bank is not deeply discharged before starting the engine.   

Hope your system works well for you. 

[anand.s]

Vito - 

Thank you for the deep insights here and visibility on others' experiences, I am grateful.

I've thought about the ML-ACR and saw that post.  Seems like it is unnecessary now that I'm only looking for boost capability, thought the ML-ACR seems like a great improvement to the current setup.   I, too, hope this works well for me.

Unfortunately, I have the Leece-Neville 200A alternator despite the C-15 motor 😞

Will keep you all posted

[Bob Blackmon]

I have the ML ACR and can talk you through it. With the ACR you can turn it off from your seat so you can have the benefit of your alternator. No idea why the picture is sideways.

Edited March 23, 2022 by Bob Blackmon

[waterskier_1]

I performed a similar mod (same functionality, but left it so I could revert back in seconds) as Bob Blackmon recommended back when I had Lifeline AGM batteries.  I did it because I didn't want 14.4 volts sitting on fully charged AGM for hours as I drove from one location to another.  I have 1400 Watts of Solar of which the original 100 Watt panel is dedicated to the Chassis Batteries and the remaining 1300 Watts to the House Batteries.  I felt no need for additional charging from the alternator for the house batteries, since I only travel in the day (even though some days may be cloudy, I've never had a problem).  I did want the BOOST Function though.  

Now that I have added LiFePO4 House Batteries, I have disconnected the BOOST Switch also.  The last thing I want to do is destroy my expensive LiFePO4 batteries trying to start my main engine.  Monaco states my starting requirements for my DD Series 60 (but basically the same for Dynasty and up) is 1900 CCA (two 12 volt 950 CCA) batteries.  If I were to attempt to draw 1900 Amps from my 585 Amp-Hour LiFePO4 batteries, the internal BMS would shut things down (that's how I have it set) but if you don't have a good internal BMS, you would destroy the LiFePO4 batteries.  All the spec's I've seen for this type of battery shows the maximum discharge current to be 1C where C is the Capacity of the cells.  That means you'd need close to 2000 Amp-Hrs of LiFePO4 batteries to meet the starting requirement Monaco states.  I doubt many have that much, and likely still wouldn't choose to use their very expensive LiFePO4 batteries as starting batteries.  I've read that some manufacturers are trying to develop some sort of Lithium Starting Battery, but haven't seen any on the market yet.  And that still would be a dedicated starting battery.

I think the reasonable solution (the one I would employ) is if you find yourself needing to BOOST, use your Toad (Towed) vehicle.  Absent that, call your roadside assistance company for help.

  Rick N.

[anand.s]

Thanks Rick - 

I suppose I could just hold the boost for 30 seconds and get a surface charge to the Chassis rather than starting off the Lithium.  I do have 1200AH and a 300A BMS but don't trust the cheap batteries.  I've never used the boost switch to be fair, just trying to keep it intact in case I sell and want to revert to SLA or AGM. 

Anand

[waterskier_1]

If you just want to temp disable the function, simply disconnect the small wires to the Big Boy and tape them. 

[granvillebarker]

I totally agree with Rick here, remove that green wire and tape it off so the Big Boy can't get activated.   That's the simple, best solution and easy to go back to normal if someone wants SLA later.   

 

Boost function isn't a good idea with lithium and should never be needed if the DC-DC is working properly keeping the chassis batteries up.  

[Bob Blackmon]

It won't automatically boost. Turn it off going down the road and to auto when plugged in. Rick Nelson, am I missing something?

[waterskier_1]

3 hours ago, Bob Blackmon said:

It won't automatically boost. Turn it off going down the road and to auto when plugged in. Rick Nelson, am I missing something?

I'm not sure what you mean by "automatically boost".  The Big Boy may be energized by either of two methods.  First, the BIRD system activates it, or second, the BOOST SWITCH is pressed & held. 

I think there may be a misleading statement above indicating that the DC-DC CHARGER would keep the CHASSIS batteries charged.  In most installations the DC-DC Charger is installed to allow charging of the LIFEPO4 batteries from the alternator.  It is a one-way charger.  If installed this way, it can not use shore power or house batteries to charge the chassis batteries.  Of course the chassis batteries would be charged by the alternator whether a DC-DC Charger is present. 

If you want Bidirectional charging a second DC-DC Charger could be installed to use the house batteries to charge the chassis batteries. 

  -Rick N

[vito.a]

Anand, Wow, a Cat C-15 in a Marquis!  What a great find.  It doesn't get any better than that.

[anand.s]

Dear all

Thank you for all the help here.  Reporting back on my solution (following Bob’s suggestion).  I ended up pulling the two pins that go to the Big Boy from J1 on the BCC PCB, gave 1 12V fused house (can pull the fuse to disable) and the other the switched “boost” ground.   Keeps everything intact, allows for the other functions of the BCC PCB to work, keeps the boost function, and makes the DC-DC + AMP-L-START serve my bi-directional charging needs.  Attached a pic.

@vito.a - the C15 is fabulous, but thirsty.  So is the Marquis, but I come from a Thor Palazzo - which was dependable through 27 national parks - but not even close to comparable.  I got lucky in finding it, bought it last year and have put 15k miles on it, currently at 105k.  Trying to get to Alaska from the east coast this summer with my young kids.   The Lithium might pay for itself in 2022 if it reduces my use of diesel 🙂

Anand