Connect to Bus Bar of battery?

navillus

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As a beginner to van electronics, I assumed that I would have to connect my Vans DC-DC charger and the shore power charger direct to the house batteries. I will be using bus bars for all my positive and negative connections for the van's electronics. However, I am looking at a couple of wiring diagrams online, and both have the DC-DC charger and the shore power charger connected to the bus bars, not direct to the battery? Can someone validate the bus bar connection or rule it out? Thank you
 

Frank in Thailand

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As a beginner to van electronics, I assumed that I would have to connect my Vans DC-DC charger and the shore power charger direct to the house batteries. I will be using bus bars for all my positive and negative connections for the van's electronics. However, I am looking at a couple of wiring diagrams online, and both have the DC-DC charger and the shore power charger connected to the bus bars, not direct to the battery? Can someone validate the bus bar connection or rule it out? Thank you
Sure!

The terminals have small surface, and not easy to hook up a charger.
Most LiFePO4 cells don't have studs that are intended for regular connect/disconnect of nuts.

The 4, 8 or 16 cells are connected with Bus-bars.

Many make a "half" ( or full) bus-bar on the + and -, it will have maximal contact with the terminal surface, and is easy to grab on to with charger clamps, or have extra threaded hole / stud to really tighten the charger permanent.
 

navillus

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Sure!

The terminals have small surface, and not easy to hook up a charger.
Most LiFePO4 cells don't have studs that are intended for regular connect/disconnect of nuts.

The 4, 8 or 16 cells are connected with Bus-bars.

Many make a "half" ( or full) bus-bar on the + and -, it will have maximal contact with the terminal surface, and is easy to grab on to with charger clamps, or have extra threaded hole / stud to really tighten the charger permanent.
Thank you for the response! To dumb it down a little, can you connect these charging devices to a common bus bar or do you need to be connected direct to battery?
 

Frank in Thailand

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To reply dumb, what do you consider as the battery"?

Cells go in series, minimal 4.
That is 3 X a bus-bar between + and -
And a + and - terminal.
If you want to charge individual cells, 3.65v, you clamp on the bus-bar on top of the terminal.

Most charge the whole array, first + and last - cell.

Probably ,14.6v for 4 cells.

The first + and last - Terminal aren't build for clamping a charger.
Permanent mounting, Is ok.

The 3 Bus-bars, you can not connect to them, you have one terminal of the first and one terminal of the last cell.

Perhaps draw diagram?
 

navillus

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To reply dumb, what do you consider as the battery"?

Cells go in series, minimal 4.
That is 3 X a bus-bar between + and -
And a + and - terminal.
If you want to charge individual cells, 3.65v, you clamp on the bus-bar on top of the terminal.

Most charge the whole array, first + and last - cell.

Probably ,14.6v for 4 cells.

The first + and last - Terminal aren't build for clamping a charger.
Permanent mounting, Is ok.

The 3 Bus-bars, you can not connect to them, you have one terminal of the first and one terminal of the last cell.

Perhaps draw diagram?
Again. I was looking for a yes or no. 12 v lithium house battery. I will try another forum, that can answer whether the chargers can go via a bus bar or they need to go direct to a battery. Thanks for your time.
 

Frank in Thailand

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Answer is NO.

As you don't understand (??) the difference between terminal and bus-bar, you should not be connecting anything.

Bus-bar is to connect cells, your 12v house lithium battery will consist of 4 cells with 3 Bus-bars.

You can not connect to those Bus-bars.

Terminals are intended for permanent contact.

If you want to clamp something on there, you need to prepare it.
With...
Permanent mounted wire or bar :)


Diagrams or picture will help a lot.

This is DIY forum, where most people build their own battery, or buy pre-build one, that just shows 2 large terminals, no talking about internal parts or BMS.

First post didn't mention any voltage, could be S4, S8 or S16, and even 2 in series ( the S stand for series)

Just that you don't know where to Connect from your wirering diagram, that you did not share...

Unless we are psychic medium...
The forum members can only provide global information based on the data provided.

That is you don't know where to connect, bus-bar or Terminal.

So don't get grumpy when you receive a global response that doesn't exactly answer your question.

How long is a piece of rope?
 
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kenryan

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If there is a cable directly from the battery to the bus bar, then electrically they are essentially the same thing. Connecting to either should be equivalent, electrically.
 

navillus

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Answer is NO.

As you don't understand (??) the difference between terminal and bus-bar, you should not be connecting anything.

Bus-bar is to connect cells, your 12v house lithium battery will consist of 4 cells with 3 Bus-bars.

You can not connect to those Bus-bars.

Terminals are intended for permanent contact.

If you want to clamp something on there, you need to prepare it.
With...
Permanent mounted wire or bar :)


Diagrams or picture will help a lot.

This is DIY forum, where most people build their own battery, or buy pre-build one, that just shows 2 large terminals, no talking about internal parts or BMS.

First post didn't mention any voltage, could be S4, S8 or S16, and even 2 in series ( the S stand for series)

Just that you don't know where to Connect from your wirering diagram, that you did not share...

Unless we are psychic medium...
The forum members can only provide global information based on the data provided.

That is you don't know where to connect, bus-bar or Terminal.

So don't get grumpy when you receive a global response that doesn't exactly answer your question.

How long is a piece of rope?
Got a great response from another member, that was in English and made perfect sense (he answered my question). Posting below.


Electrically its the same connecting directly or using buss bars , ( providing the correct gauge of cable is used for connections).
The practical limitations are that multiple connections to a battery terminal may/will exceed the capacity of the bolt or stud connection point and over stress the mechanical fixing. Its difficult also to 'stack' terminations as each termination and cable needs exit space. The usual result of trying to make multiple connections is an unreliable system with possible failure.
Its good practice to limit the number of terminations to a stud/bolt to two cables and ideally only one cable.

A further point is for safety and a need to meet codes and regulations, there needs to be over current protection for all circuits connected to the battery. This protection needs fuses or circuit breakers as close as practical to the battery. In practice a fuse/breaker between the battery positive and positive buss bar is used. As for the battery negative its useful to to have a current monitoring shunt in the path, this connects between the battery negative post and the negative buss bar.
typical use of buss bars, note the fuse at the battery positive post
fuse block 3.jpg
Incorporating high current fuses with the positive buss bar
fuse block1.jpg
fuse block 2.jpg
Mike

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Frank in Thailand

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:)

Without schematic...
And my head full with building DIY LiFePO4, I had in mind the therm bus-bar "only" used with adjoining cells to make a battery...
Did not think about being used as a connection point for wires :)

Pictures and schematics help so much to talk about the same thing 👍👍

@ mike : good answer!
Feel free to reply in the thread next time, so we can all learn from it.

(I know I did)
 

navillus

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:)

Without schematic...
And my head full with building DIY LiFePO4, I had in mind the therm bus-bar "only" used with adjoining cells to make a battery...
Did not think about being used as a connection point for wires :)

Pictures and schematics help so much to talk about the same thing 👍👍

@ mike : good answer!
Feel free to reply in the thread next time, so we can all learn from it.

(I know I did)
Of course, thank you!
 
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