question

bene avatar image
bene asked

Orion TR Smart DC-DC to charge boat diesel starting bank?

It's good to see the Orion Smart series officially announced on the blog today:

https://www.victronenergy.com/blog/2019/10/10/new-product-orion-tr-smart-dc-dc-charger/

But while it's usually shown set up to use input from a vehicle start battery to charge an auxiliary bank, I want to do the reverse. In my case there would be two alternators on the same 450hp boat diesel feeding a 440ah Firefly AGM 12v house bank with the Orion Smart 12/12-30 supplying the smaller Dekka AGM 12v starting bank. That way I'd get more use from the alternators, plus alternator redundancy, and the system would be ready if I ever switch the house bank up to Lithium-Ion.

Am I thinking straight?

PS The boat already has BMV712/Smart Solar/Venus system that I greatly appreciate:

https://vrm.victronenergy.com/installation/30059/share/d9560ba7

How will Orion eventually integrate with the family?


chargerOrion DC-DC Converters not smart
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5 Answers
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

I've done some boat installs where I just use an AC powered battery charger, fed by inverter and / or shore power. this way the (lead acid) starter battery is always maintained by a proper charge algorithm.

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bene avatar image bene commented ·

Thanks, Daniel, but that won't work for me. The boat does have a MultiPlus 12/2000/80 set up to trickle charge the starting bank, but it's rarely on shore power and the inverter is only used for non-essential loads like the microwave oven.

I guess this is my question put simply: Is there any drawback to using the Orion TR Smart to charge the boat's starting battery bank from the house bank?

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timmermc avatar image
timmermc answered ·

Sometimes the easiest solution is the cheapest. I had a 5A victron charger as a spare and I installed it between an also not much needed inverter who is feeded by the house bank. It was actually an experiment from me, but it became fixed and is working fine. Keeps the starter battery topped all the time and uses little power.

I think that is the solution Daniel also proposed, use the inverters output...

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bene avatar image bene commented ·

Thanks, but (as I told Daniel) my boat is set up so the inverter is nice but not really needed, and I don't want engine start battery charging dependent on it. What I want to do is commonly done with a fairly inexpensive Automatic Charging Relay (ACR) but I think the Orion Smart has some valuable benefits.

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vineyardgray avatar image
vineyardgray answered ·

Hi Ben - I agree totally with your premise - the alternators should be used to charge the house bank as it will have the greatest load (start loads are relatively short - why waste two alternators on the start batteries that will be quickly charged?


DC to DC chargers are the answer. I hope that Victron has a solution for us.


Have you read this?

https://seabits.com/victron-wakespeed-battle-born-power-system/

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bene avatar image bene commented ·

Thanks, Vinyardgray, and, yes, I've read about Steve Mitchell's dual alternator boat system at SeaBits. And while I think that a Victron Orion DC-to-DC charger will do the same job as his Sterling charger, I'm hoping for reassurance about making the house bank the source instead of the starting bank.

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vineyardgray avatar image vineyardgray bene commented ·

I see no reason that it would not work in that way and I will put my money where my mouth is when these become available to North American dealers. It is nice that there is bluetooth function but the data sheet does not describe what it will display if not the voltage in and out (which the blog reads as "coming soon").

I was also looking for buck-boost functionality which these appear to have.

I would like clarity from Victron on what this sentence from the data sheet means, however:

If set to nominal or lower than nominal, the output voltage will remain stable within the specified input voltage range (buck-boost function). If the output voltage is set higher than nominal by a certain percentage, the minimum input voltage at which the output voltage remains stable (does not decrease) increases by the same percentage.


Can the input be "set"? Or does it just take what it gets (and then shut off at 7V as the data sheet suggests)? What does "by a certain percentage" mean?

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vineyardgray avatar image vineyardgray vineyardgray commented ·
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mike-g avatar image
mike-g answered ·

Something to consider is that the Orion does not have any temperature compensation or (AFAIK) configuration for bulk voltage settings and absorption current limits. As a DC-DC charger, it is therefore somewhat limited in charging lead acid chemistries.

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amped-up avatar image
amped-up answered ·

Hi All,

Was there every a final opinion or trial of using the the Orion Tr to charge the start battery from the house battery? I was considering this as well.

I have a 500AHr AGM house bank and a 100AHr start battery. The house bank is charged by a 100A diesel alternator (with a smart regulator), a Victron MPPT 75/15 solar charger, and AC charger from shore or genset (now only 40A, also needs upgrading). Appears the existing ACR is not working, so was thinking to replace this with the non-isolated 12/12 30 which would then also allow eventual upgrade to lithium house bank. Or perhaps the 12/12 18 would be fine?

The start battery is used for the main engine (or "Auxiliary", given this is a sailboat) and 5kW generator. Only want to keep it topped up after start.

Thanks, Craig

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