Do batteries in parallel need seperate breakers?

DIY
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I’m planning a horseback of 3 lithium 24v 200Ah jn parallel in a sailboat. They’ll be used with a multiplus 24/5000 and high output alternator.

I’ll put class t fuses close to the batteries then connect them to a lynx system with lynx bms…

I understand I can use the lynx bms as masterswitch. But then the batteries will remain connected to each other through he lynx power in. Would it be advisable to add seperate dc breaker to be able disconnect the batteries?

Thanks for advice

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Do you mean a circuit breaker like a resettable fuse. If so, a 200A breaker with a fault current of over 10,000A (battery voltage = 28V, internal resistance = 2mOhm, fault current ignoring cable = 28 * 1,000,000/2 = 14,000A). If so these are very expensive and with the Class T fuses would not really be required.

Or do you mean isolation switches between the Class T fuses and the Lynx BMS, which would be a lot cheaper.

Personally, I have not done this, I just have a Class T on each battery before they connect to the Lynx BMS like a lot of the Victron schematics. I would have used the Class T power in but did not have the room. You will rarely need to disconnect a single battery, if you do, remove the fuse. In normal operation you do not need to power down the Lynx BMS.

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I meant isolation switches.

But I gather from your reply they are not needed.

Same thing about class T powerin here, don’t have the room for it. And to be honest I prefer the fuses on the side of the battery. Just in case of a dead short.

Thanks

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