Battery disconnector

[Isetech]

An interesting topic which popped up on this forum, the use of circuit breaker type disconnectors for batteries.

Lets say you connect 2 x 5 kwh (100 amp/hr) batteries to one inverter.

Someone started th trend of using fuse type disconnectors, and as with anything the rest just followed.

If the batteires have built in circuit breaker type disconectors, do you still have to install a fuse type disconnector ?

This is an interesting question, similar to the fact that you have to fit a disconnector on the wall for safe isolation for a machine.

If the battery is part of a system installed, why would you need to install another disconnector on the wall.

If you switch off the disconnector which is part of the battery and disconnect the wires, and leave them hanging loose, its safe right, actually its not, the battery chargers and discharges.

However if you have battery terminals, which are insulated, then it should be fine right?

What is the purpose of the switch disconnect, to safety isolate the battery?

[GCE]

DC breakers are not all suitable for Bi Directional

The fault levels can be high and the individual CB that may be fitted on the unit sometimes only isolate the BMS side

The majority of manufactures instructions for installation require external protection and when setting up banks have extra requirements otherwise your warranties fall away

[Justloadit]

I would think that if you have a number of batteries in parralel on a bus, and you would like to service one of the batteries, for what ever reason, how do you isolate the cables from the other batteries with out a complete shut down?
Having an isolator for each battery, makes this a simple task. Switch the battery off you need to service at the battery control. Open the isolator, and now you can disconnect the cables with out having live wires hanging about.

[Isetech]

This makes things interesting, considering the way inverters are setup. This is another reason why it is so important to make sure you use the right people to install and maintain the "system". There are pro's and con's with putting batteries (5 kwh) in parallel instead of 1 big battery (10 kwh+)

Fro example, if you remove 1 ot 2 batteries from a system, you would need to make adjustments to the charge discharage parameters.

I would think that if you have a number of batteries in parralel on a bus, and you would like to service one of the batteries, for what ever reason, how do you isolate the cables from the other batteries with out a complete shut down?
Having an isolator for each battery, makes this a simple task. Switch the battery off you need to service at the battery control. Open the isolator, and now you can disconnect the cables with out having live wires hanging about.