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ger50 avatar image
ger50 asked

Orion-Tr 12/12 30 directly connected to the alternator

Hi,

I am using since a while LifePO4 batteries on my boat.

Each battery features an active BMS + balancing.

The starter battery is a 20Ah (CCA of 400A for 5s), while the service battery is an 80Ah battery.

Between them there is a Septor 1275 which allows for charging more than one battery.

The starter battery is connected to the alternator (Hitachi 80A on an Yanmar 3YM20 engine).

For regatta, all fine. For cruising (10hr +), the service battery does not get completely charged when motoring.

I was planning to fit in an Orion-Tr-Smart charger between the alternator and the rest of the circuit (starter battery followed by the Septor 1275 followed by the service battery).

Any drawback in doing so? why is this case not covered by the reference schematic considered?

I understand the Orion is a B2B, but what is actually the diff compared to an A2B in this case?

Any feedback, suggestion, welcome.

Thanks,

SaverioVictron.jpg

battery chargingorion-tr smartalternator
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6 Answers
kevgermany avatar image
kevgermany answered ·

The Orion expects/is designed for reasonably stable input voltage. A battery between that and the alternator stabilizes the alternator output.

I guess your charging problem is lack of capacity in the Septor. If it's an A2B design, probably would be better to add a second Septor not an Orion. There's no guarantee the Orion will work. It might, but...

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gert-kruger avatar image
gert-kruger answered ·

Seems fine, see https://www.victronenergy.com/upload/documents/Engine-on-detection-set-up-Orion-Tr-Smart-DC-DC-Charger-EN.pdf

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kevgermany avatar image kevgermany ♦♦ commented ·
Not sure I understand. Each example there also has a battery connected directly to the alternator. As I understand you, there will not be a battery connected to the alternator
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Sarah avatar image
Sarah answered ·

Hi @GER50,

A couple of thoughts and I’ll be honest up front - I am not a real fan of using lithium as a starter battery (but I get it they have size and weight advantages).

- The Hitachi 80A is a temperature regulated alternator. When it gets hot it lowers its output voltage to protect itself. This is good for the alternator but not great for charging lithium batteries.

- Should the Orion (as per your diagram) disconnect from the alternator (under voltage) (or the internal BMS disconnect) you risk blowing the alternator diodes. Not good for alternator.

- The Septor 1275 is rated at a max 75 A continuous so it should be ok but may max out depending on additional load.

There are a number of options but my preferred solution (and probably the most cost effective) would be to use an AGM starter battery connected to the alternator with an Orion connected in parallel (B2B) to charge the lithium house batteries. Every situation is different. I hope that helps.

Sarah

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kevgermany avatar image kevgermany ♦♦ commented ·
Agree. But what to do with the existing lithium starter?
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Sarah avatar image Sarah commented ·

Okay so assuming the alternator is going to continue to operate without being damaged (and you understand the risks) the lithium starter stays. It then comes down to the difference between power generation and power consumption. My questions would then be 1) after a few hours cruising what is the voltage coming from the alternator (is it > 13.2 volts - activation voltage for the septor) and 2) what is the comparison between power production and consumption (is the house battery charging or discharging)? Knowing the answers will help to point you in the right direction for designing the best and lightest solution.

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ger50 avatar image
ger50 answered ·

Thanks Sarah, the problem is that we are talking about a racing sailing boat, each kilo counts.. I am using the Lifepo4 20Ah start battery since 4 years w/o problems..


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ger50 avatar image
ger50 answered ·

@Gert Kruger , indeed but why in their schematic there is still the backup battery in parallel to the alternator....if any one from Victron could reply this would be helpful to clarify how does it work..


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ger50 avatar image
ger50 answered ·

@kevgermany Hitachi 80A over time and temp will provide much less than 80A so septor 1275 should be more than enough, I guess. Thx

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kevgermany avatar image kevgermany ♦♦ commented ·
So why when cruising is the service battery not getting enough charge? Is the Septor not able to manage batteries of different capacities?

Or are the loads much higher and the motor isn't running?


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