Bi-directional Relays (BIRD)

[rarebear.nm]

Our MH has a standard battery cross connection solenoid. Allowing charging of the the house batteries from the engine.

I'm considering installing a bi-directional replay to permit charging the chassis battery from the converter. I have looked at few choices and presently favor the Intellitec 0000362100 B.I.R.D. What are people's thoughts about this unit or is there a better unit?

[nodine]

Originally Posted by rarebear.nm

Our MH has a standard battery cross connection solenoid. Allowing charging of the the house batteries from the engine.

I'm considering installing a bi-directional replay to permit charging the chassis battery from the converter. I have looked at few choices and presently favor the Intellitec 0000362100 B.I.R.D. What are people's thoughts about this unit or is there a better unit?

I like this one because it is magnetically latching. The solenoid is not constantly drawing power and producing heat.

https://www.bluesea.com/products/762..._-_12V_DC_500A

Bob

[Isaac-1]

Why not just install a Trik-L-Start Mega TRIK-L-START Starting Battery Charger/Maintainer

[twinboat]

I installed a Cyrix combiner across the boost solenoid terminals on my old class C.
I used 2 short 10 gauge wires and a 16 gauge ground, and mounted it close by..

$45. On Amazon

[rarebear.nm]

Originally Posted by twinboat

I installed a Cyrix combiner across the boost solenoid terminals on my old class C.
I used 2 short 10 gauge wires and a 16 gauge ground, and mounted it close by..

$45. On AmazonAttachment 328791

Twinboat,

Did you leave the existing solenoid in-place and just added the Cyrix in parallel to it with the short jumper wires? Did the existing solenoid only work as a booster or did it also connect the house batteries to the engine for charge while the engine was running?

It seems that you could replace the existing solenoid totally by using the remote switch feature of the Cyrix.

[twinboat]

I left the original in place. It carries more current for boost starting.

I had 300 watts of Solar on it so I never needed to used the AUX switch.

[rarebear.nm]

Originally Posted by twinboat

I left the original in place. It carries more current for boost starting.

I had 300 watts of Solar on it so I never needed to used the AUX switch.

Thanks

[hpdrver]

Rare bear

This is a photo of what Coach House are installing now on their coaches. It charges both batteries on shore power. It also is connected to a switch to combine batteries for starting purposes.

[twinboat]

There is also the BIM225 as a replacement for the solenoid. Its bi-directional.

There are many others out there.

[SteveJ.]

I use this one.

https://www.bluesea.com/products/761...12_24V_DC_120A

175 milliwatt current draw when engaged, more than the Blue Sea 7622, likely a lot less than the Bird. Automatically kicks out when engaging the starter. A bit more $ than the Bird, quite a bit less $$$ than the 7622. It is only rated for 120 amps continuous which could be an issue with large lithium battery setups and/or big alternators. As charging current for the chassis battery from the alternator bypasses the separator(depending on installation) the 120 rating is good for most of the non massive battery banks.

We primarily boondock/dry camp using solar.

[rarebear.nm]

Thanks to everyone who responded. I think I have a pretty good handle on this issue now and will proceed in the near future.

[Phil G.]

Originally Posted by rarebear.nm

Our MH has a standard battery cross connection solenoid. Allowing charging of the the house batteries from the engine.

I'm considering installing a bi-directional replay to permit charging the chassis battery from the converter. I have looked at few choices and presently favor the Intellitec 0000362100 B.I.R.D. What are people's thoughts about this unit or is there a better unit?

An for-what-it's-worth additional approach to consider might be what I do to charge and maintain our motorhome's chassis battery:

Since to use the converter means that you're on hookups, this means that your RV has 120V AC power at it's household receptacles. When on hookups I just plug an inexpensive small 120V AC battery charger into a receptacle in the coach and then plug the charger's battery charging output into a regular cigarette lighter receptacle in the dash of the cab.

The cigarette lighter receptacle on the dash is always "hot" - meaning that it's always directly connected to the chassis battery (via a fuse) - so a battery charger plugged in here can then charge, and keep charged, a low chassis battery.

I use a small battery charger with a long output line and a cigarette lighter male plug on the end, so it nicely plugs right into the dash cigarette lighter receptacle.

This has worked well for us for years to both charge the chassis battery, and keep it charged when our motorhome is being stored while plugged into 120V power.

[rarebear.nm]

Phil, thanks for idea. One of the key desires is recharge the chassis battery while on solar power. Thus I do not want to convert from 12 v to 120 v in the inverter and back to 12 v at the charger. Just want a solution based on only 12 v options.