Battery Isolator clicking

[Fred Brooks]

    That era BIRD and Big boy were first generation and there was a situation that developed as the batteries aged or were neglected. I first ran into it on American coach products and then Monaco products. The key was the voltage required to get the BIRD to engage the Big boy solenoid so house and chassis batteries were charged. Here was the scenario: Chassis batteries were down to 11.9 to 12.0 volts from storage or age. If the coach was then plugged into shore power, the inverter/converter would start charging the house batteries. When the threshold voltage of 13.1 to 13.3 was reached, the B.I.R.D. would then tell the Big Boy relay to engage and also start to charge the chassis batteries. After a short time, the "combined" voltage of the chassis and house batteries dropped below the threshold voltage and the Big Boy dropped out. Then the charge voltage from the inverter/converter would eventually regain the threshold engagement voltage and the Big Boy would again engage. This clicking on and off of the Big boy really annoyed customers. The "fix" was to start the engine and fast Idle @ 1000 rpm for 15 to 20 minutes to raise the surface voltage in the chassis batteries. Eventually the combined voltage of the chassis and house batteries would satisfy the BIRD and keep the Big boy solenoid engaged.
  Fred

[Mike Shumack]

Fred, how can you tell if you have the Big-Boy/BIRD first generation or a later (second) generation? Do they look different - or have different part numbers?

Also, is it the Big Boy isolation relay or the BIRD controller (or both) that have different generations?

If one buys a new Big-Boy or BIRD, would they be getting the latest generation? (assuming the latest gen is a direct replacement for the earlier model).

Thanks

[Bill Sprague]

Mike,

Don't have the Beaver anymore but the '04 we owned had a BIRD/Big Boy.  Our new rig has a gizmo that seems to do everything the same or better but is smaller and cheaper.   It seems to me that it might make a reasonable replacement.

Cole Hersee 48530 Smart Battery Isolator 200A

https://smile.amazon.com/gp/product/B00LMGPHW2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://m.littelfuse.com/~/media/commercial-vehicle/application-guides/littelfuse-if-161-48525-smart-battery-isolator.pdf

https://www.littelfuse.com/~/media/commercial-vehicle/hot-feeds/littelfuse-battery-management-smart-isolator-d617-info-sheet.pdf

[Tim Manninen]

Joel,
Thanks for the info. I question the accuracy of my Alladdin screen. The other day the chassie batteries showed 12.4 volts but when I started the motor I was surprised it turned over and started like it was 14volts.
If the batteries get low again I'll use your advice.
Thanks again,
Tim

[David T. Richelderfer]

12.4 volts is just shy of 80% charged.  100% charged is 12.6+ volts.

[Fred Brooks]

    Mike, please post a picture of the B.I.R.D. delay relay on your coach. Thanks, Fred

[Mike Shumack]

Hi Fred,
I'm not having any problems with my equipment. I'm just asking to learn, and in case I ever need to replace anything I want to be sure to get the latest/correct parts.

I have added an LED display to the compartment door that houses the Big Boy and BIRD. I am measuring voltage on both of the Big Boy terminals. if they show equal voltage (+/- 0.1 V) I know the relay is closed and both House and Chassis batteries are charging.

Thanks

[Fred Brooks]

   Thanks Mike, your delay relay is the d-2 which as far as I know is the BIRD that was used starting in 2004. There was nothing wrong with that system engineered by Intellitech. All I was trying to share was if owners don't monitor the health of their batteries, there will be symptoms that start to show up as I stated in my previous post. The only weakness that I saw was the beating the contacts inside the "Big Boy" was taking over the years and the Forum has addressed that.
  BTW I like your monitor that you added to keep an eye on things. Fred