OK, What is a "BIRD" system in reference to charging.

duplicate deleted

Yep, that's a BIRD.

Thanks to all for contributing here. I was thinking it is what all of you described what it was. I'd just never actually seen or read what it's actual function/operation was/is. It sounds dangerously close to what we had in our '99 Fleetwood Bounder 34V with the F-53 Chassis and the V-10. It had a "BCC" or, Battery Control Center that had/has what's called I think: Bidirectional-time delay-relay in it. When conditions are met, the alternator charges both house and chassis batteries. So, it definitely sounds close in operation. Thanks again for your info and help here.
Scott

BIRD BIdirectional Relay Delay

It is a small device that measures the voltage on both sides of the isolator relay and if the voltage is in the "Charging" range, it will, after a precision delay of somewhere around 30 seconds. Engage said relay so that the house batteries are charged by the engine alternator.... OR, if parked and plugged in, the chassis (Engine) battery is charged by the house converter.

Very useful device.

RoyB wrote:
This is probably as good as anything for describing what a BIRD is...

I searched GOOGLE using your post title 'What is a "BIRD" system in reference to charging'... Google says...

Bi-Directional Isolator Relay Delay

I didn't know what one was either...

Roy Ken

Good info, thanks.

It's a logic board and 2 or 3 solenoid relays. If it senses charging voltage on the house or chassis, it closes the relay that connects the two sides so that both get charged. That operation is subject to certain requirements being met, so it won't happen if the charging side is deeply discharged. The other 1 or 2 relays are latching relays which serve as disconnects for the house and optionally the chassis.

I see YC 1 said about the same.

I will doing something similar with the BLUE SEA SIACR 7650 Series SMART relay. This unit monitors my Truck ALternator charging system and when it senses the Truck ALternator is in charge mode it switches in the remote connected batteries. This switch mode is adjustable to different DC Charging voltages depending on what your truck systems uses. The idea here is only when your truck start battery is being charged the remote batteries are being charged. This prohibits the remote batteries from draining down your truck start battery.

This used to be done with large current DIODE but these days the large voltage drop (.6VDC) across the DIODES messes with the boost and normal charging modes which is normally only around .8VDC difference coming from the alternators so direct connected solenoid relays must be used now. These smart relays switches in and out when required to be used.

This is going to be my concept for having two 150AH 12VDC batteries in the bed of my truck to run a bunch of two-way radio setups and also support my camping requirements when connected to the my OFF-ROAD POPUP camper trailer which also has two each 150AH 12VDC batteries.. When being used for the two-way radio ops these batteries will be charged by the truck alternator- when connected to the OFF-ROAD POPUP the on-board converter/charger will keep the batteries charged up.

This is also the way I can spread around the weight of the extra batteries which would be a total of 328LBs for the batteries if all were mounted in the same location...


Always working on some mods...
Food for thought...

Roy Ken

Just one of dozens of threads on the subject

Basically, any charging source causes the battery banks to combine so all batteries get charged.

Several failure items are the solenoid that combines them or the BIRD device itself.

This is probably as good as anything for describing what a BIRD is...

I searched GOOGLE using your post title 'What is a "BIRD" system in reference to charging'... Google says...

Bi-Directional Isolator Relay Delay

I didn't know what one was either...

Roy Ken