Question BIM in 2022 LADP?

[redbaron]

fwiw, this discussion might interest you, re dc to dc nor special BIM

Maybe switching to Lithium House Batteries - iRV2 Forums

I'm sure thhe info I am looking for has already been addressed in this great form, but I can't find it so: I have a 2018 New Aire and the AGM house batteries need replacing. Am considering going

www.irv2.com

Thanks…that does help.

 

[redbaron]

Well, not really! It's said a lithium battery acts much the same way a capacitor reacts! It will completely discharge very fast!

I could see modifying the relay system to switch the starting system from one battery to the other. But to introduce a short circuit to a lithium battery is pure suicide!!! Thank God your lithium battery has short circuit protection!!!

And the additional DC to DC charger will also protect against reverse /short

 

[Kevin D Pem]

And the additional DC to DC charger will also protect against reverse /short

We are not even talking about the same circuit!!!
The only time the load circuit touches the charge circuit is at the batteries!!! What the charge circuit offers is independent from, therefore does not apply to the load circuit!!! Diagram it out!!!

 

[redbaron]

I am talking about the house side at the solenoid. Putting a dc to dc there facing the solenoid will prevent reverse flow to the lithium but will allow the lithium to power the solenoid and thus power the chassis battery.

If a short occurs, it’s limited to 50amp before protection kicks in.

 

[Ddmo]

This?

https://www.victronenergy.com/dc-dc-converters/orion-xs-12-12-50a-dc-dc-battery-charger

Sure looks interesting.

Yes. That’s it.

 

[Kevin D Pem]

I am talking about the house side at the solenoid. Putting a dc to dc there facing the solenoid will prevent reverse flow to the lithium but will allow the lithium to power the solenoid and thus power the chassis battery.

If a short occurs, it’s limited to 50amp before protection kicks in.

Clearly we are reading a different book! I'm still talking about using a boost circuit, on the load circuit. Connection from lithium to "weak" agm or other battery, is by definition a short!

 

[redbaron]

So am I.

Boost is what activates the solenoid to provide the functionality.

Using my design would allow this feature to work for boosting the chassis and let it start safely off the lithium house battery.

The existing circuit for charging the house from alternator would have the DC to DC facing the house battery. This provides for the function as originally designed, while offering protection of shorts and ensuring current draw doesn’t exceed 50amp.

If the chassis battery’s are internally shorted or truly dead, then the boost feature is irrelevant and won’t help anyway. But if they are just very low, it will work the way it did prior to lithium.

 

[Richpatty]

Clearly we are reading a different book! I'm still talking about using a boost circuit, on the load circuit. Connection from lithium to "weak" agm or other battery, is by definition a short!

Huh?

 

[Kevin D Pem]

Huh?

A quote!

"

In the context of a battery (or any power source), we usually mean it to be a load that is far too large for the source. Any battery, whether a high voltage or low voltage battery, will be 'short-circuited' by putting a low or zero resistance load on it.

A short circuit usually produces damaging conditions for the battery, and the load, if maintained for enough time. At best, the battery will be run down quickly. At worst, the battery may catch fire, burst itself or its container, or the load start a fire."

 

[redbaron]

Kevin, one of us is clearly confused on the purpose of the DC to DC charger I have mentioned.

I will do some more research because right now I feel pretty confident in my design and intended usage.