piemuth avatar image
piemuth asked

Buck Boost connection to ground always necessary?

I need some help.
I just wanna install my buck boost in my truck.
24V Car-batterie --> 24 lithium in the Cabin.

In the manual is written, that I should connect at first the ground to both systems (before they are not connected via ground (-).

So no problem, after it connecting the both plus- cable to each battery.

What is when I want do disconnect on of the battery-circle? I will have a main switch on the car-batterie on the minus-side. In this case I would disconnect one of the ground cable from the buck boost..... is this possible? Would be the same, if I had to change a battery. Normally always the ground connection is disconnected first from the battery, for any kind of work.

Even the cabin can taken of from the car. so I have to disconnect the buck boost completely with an connector (minus and plus from car-circle at the same time) ....possible or not? I will i destroy the buck boost?

Out from the Manual:

First connect all GND cables to the converter, the battery and the chassis, and then only the positive (+) cable. This is important because in the converter everything refers to GND.

When the two plus (+) cables are connected without GND, the potential difference between the plus (+) connections ensures uncontrolled and unsecured currents!
Always check that the GND connection on the middle M8 connection is correctly connected.

The converter has no reverse polarity protection!

Thanks for an advice or experience.

Best greetings

Lithium BatteryOrion DC-DC Converters not smart
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1 Answer
gubby avatar image
gubby answered ·

The connection to ground is neccesary - the unit won't work at all without it. Firstly, the unit's internal control circuits will use the ground for power, and also any difference between the currents of the input/output terminal will be reflected in the ground current.

This is even more the case when the converer is increasing/lowering the voltage, where there will be a larger current difference. In your case you are going from 24v to 24v, but there will still be a small difference in voltage/current between the input and output.

A device that had no ground connection would be unable to do anything other than act as a variable resistor, which would be incredibly inefficient, and there would be no way to boost the voltage.

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