question

dhruvkumar avatar image
dhruvkumar asked

Using Orion Smart to charge starter battery


I have marine setup with a 30Ah lead cell starter battery and a 200Ah leisure Lithium battery. I am using a Victron Orion 18A to charge Lithium battery via alternator when the engine is running. The starter battery is directly connected to the engine and the input of Orion.

The issue is that 18A is way too low to charge a 200Ah battery and I am struggling to make ends meet with just solar. Is it ok to connect alternator to the Lithium battery directly and use Orion to charge the starter instead. This would mean the lithium battery along with alternator goes in Orion input and lead acid goes to the output.This will let me get around 60A output from the alternator to Lithium. PS - this is a dumb alternator from the 80s which can potentially blow up when the Lithium BMS cuts off input. Usually the starter battery can accommodate and protect alternator but in this case i don't know what will happen.

orion-tr smart
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4 Answers
kevgermany avatar image
kevgermany answered ·

Don't.


Charge starter direct from alternator.

Get a bigger Orion to charge lithium from starter battery or alternator. But keep below the alternator max output for safety. Keep first Orion as spare.

Or You could retain the existing Orion, add a second, use both in parallel to charge the lithium from alternator. Make sure both configured the same, according to the battery specs. Make sure total Orion output rating lower than alternator output as above.

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Sarah avatar image
Sarah answered ·

Hi, my understanding is that it would not be good, for either the lithium battery or the alternator, for them to be connected directly. Perhaps you would be better served by adding a second Orion charger to the system (or replacing the existing charger with a larger model). You need to be thinking about a) managing the lithium battery charging cycle and voltage, b) overcoming a BMS disconnect, and c) not overloading and cooking your alternator. Last point - Just because your alternator can output 60 A it doesn’t mean it should. Keep it at half load to prevent it from over heating. I hope this helps.

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hjohnson avatar image
hjohnson answered ·

You can do this (it’s what I’m planning for my boat) but you will absolutely need to switch to an alternator with external regulation. The external regulator will monitor the alternator and control it so that it does not overheat, and run it as hard as possible.

The best option on the market right now is the Wakespeed WS500. It will cost you close to $600 USD, but will integrate with your victron system via CAN Bus. It will also give you a lot more control over your alternator, important if like me, you’re connecting a large alternator to a small engine.

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kevgermany avatar image
kevgermany answered ·

You might find that this results in a burnt out alternator. I've no idea what the Sterling device does, however. You also need to make sure the lithium bank is ok for direct alternator charging.

With two engines/alternators wired the way you have, probably no risk of running out of starter battery in frequent stop/restart, but with a single one.... I like the trickle to starter as an extra, doing that on my camper. No more dead starter batteries from standing too long.

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