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dbrouwer asked

Orion-TR Smart DC to DC charger for LiFePo start battery

I have replaced the standard start battery in my Sprinter camper with a high CCA lithium start battery. Because the alternator over charges the LFP battery and puts the BMS into protective mode, and because apparently there is no external voltage regulator available for the Mercedes alternator, I have elected to install a Victron Orion Smart DC to DC charger. So the alternator goes to the Victron input, and the output goes to the start battery. However, when I start the engine, the Victron does not come on, and the charge light on the Sprinter stays on. To get it to start charging, I have to connect the alternator output to the battery, just briefly. Then the Victron comes on and the charge light goes off. I have disabled both the Victron Engine Shutdown Detection and the Input Voltage Lock-out.

So my question is: Is this to be expected, and what's is the solution?

Thanks very much for any feedback!

orion-tr smart
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3 Answers
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kevgermany answered ·

You need a battery between the alternator and Orion.

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dbrouwer answered ·

I understand that if I put a lead/acid battery between the alternator and the Orion, that will solve this problem. But if I put a lithium battery between the alternator and the Orion, the lithium battery will be overcharged. So what's the solution that will fulfill the promise that the Orion-TR "Supports both lead acid and lithium batteries" as the documentation indicates?

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kevgermany avatar image kevgermany ♦♦ commented ·
The Orion is a charger, has settings for charging both chemistries. It's up to you to provide suitable input. An alternator alone is not suitable input.

Your vehicle is designed for a normal AGM starter battery. And this should be the starting point in your modifications.


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dbrouwer answered ·

I am obviously missing something about how the Orion-TR works. I don't understand why it doesn't see voltage from the alternator once the engine starts. But ultimately what I want is a solution which allows me to use a LiFePo start battery. Since high CCA lithium batteries are now available on the market, I suspect I am not alone in wanting such a solution. Does anyone have any suggestions?

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