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bezda avatar image
bezda asked

Smart Battery Protect and Orion DC-DC

Hi, I'm planning to connect Orion DC-DC 24-12 into my lithium setup to support 12V loads and I was planning to connect that _after_ the Smart Battery Protect. Having thorough look into the SBP manual, it says that "The short circuit protection of the BP will be activated if you try to directly connect loads with capacitors on their input (eg inverters)". Does Orion have capacitors that could cause short circuits, or is it fine to connect it as I intended?


Thanks

Battery Protect
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3 Answers
bathnm avatar image
bathnm answered ·

Why not use the BMS to shut down the Orion TR. you can use the H port as a remote switch. Details are in the Orion TR manual.

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bezda avatar image bezda commented ·

The Orion is about 10 metres away from the BMS, so I'd need quite a big signal cable, plus another 10m of separate cables dedicated to the Orion (it's for 24V & 12V sockets)

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sebcbien avatar image sebcbien bezda commented ·

No problem with 10m for a signal cable, amps are very low on the remote input.

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sponk avatar image
sponk answered ·

I have the same setup: A Orion 24/12-25 after a BP65. The BP65 does not go into short circuit protection, when the Orion is connected. Maybe the capacity is too small.

How did you end up with your installation?

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hm4 avatar image
hm4 answered ·

I am running a Orion 24/48-8.5 behind a Smart Battery Protect 220A. I can tell for sure that the Orion will kill the SBP sooner or later if you directly switch the Orion as a DC load on the SBP-OUT. I have destroyed two SBPs now - first one by accident, second one for confirmation ... The first SBP is short circuited between IN and OUT now. The second SBP still has ~220 Ohms resistance between IN and OUT but massively drops voltage already with very low loads (<10W). Plus it makes the Orion green light blinking rapidly if loads are connected over Orion output terminal. In both cases, Bluetooth connection to the SBPs is still working and the load disconnecting buttons of the SBPs in the app are useable with changing states: however with no real effect. You can switch it how often you want - physical load remains always on even it the app says it is disconnected. That is, the Orion will always stay online and is drawing power even in an undervoltage situation of the battery: the SBP is not able to disable its OUT port anymore.

The manual of the SBP clearly says to NOT connect inverters or chargers with their DC ports to the SBP-OUT due to reverse currents. Well, this should be changed to NOT connect any loads to SBP-OUT that have capacitive inputs.

When connecting the Orion to the battery, there is a short but high inrush current to charge the capacitors over Orion input terminals until they reach high resistance. You can watch resistance going up slowly if doing a continuity test with a multimeter between +/- input of the Orion while disconnected from battery. If you switch polarity of the multimeter within a short time, you can watch resistance going down to 0 and then going up to high resistance again. Every capacitor that gets charged will discharge eventually. And this discharging causes the reverse current that ruins the SBP. Especially when the Orion is used with high loads, or the SBP is triggered for undervoltage condition, or the Orion goes offline or if you disconnect the battery, and so on.

If you follow the drawing the in the SBP manual and only connect the remote on/off switch of the Orion with SBP-OUT, everything is fine.

Can anyone else confirm that the Orion may not be used as a DC load behind a Smart Battery Protect?

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