16 Cell Multi Slave Board

Threads relating to the BMS system begun by Peter Perkins

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retepsnikrep
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Re: 16 Cell Multi Slave Board

Postby retepsnikrep » Mon Oct 24, 2011 5:35 pm

Thanks goodness for command seven. :wink: Those cotton picking dry joints :cry:
Regards Peter

Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.

glyndwr1998
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Re: 16 Cell Multi Slave Board

Postby glyndwr1998 » Thu Nov 05, 2015 4:01 pm

Hi guys,

i realise this is an old thread, needing some info on how to connect 1 x 16 cell slave board to the master pcb version 2.

Ive acquired a set up off Greg, and want to use 1 x 16 cell slave pcb with a 48v lifepo4 battery for energy storage.

I just need some help on how to connect the master buds and slave bus connections form the master pcb to the slave pcb. On the 16 cell slave pcb there is the slave in and out connections and conn3 and conn4 for the master bus conections, and on the master there is 1 connection for the master and the slave connections.

Any help greatly appreciated.

Many thanks, Anthony.

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Re: 16 Cell Multi Slave Board

Postby GregsGarage » Thu Nov 05, 2015 7:02 pm

Here are some basic instructions.

The slave bus has 2 wires and sends commands from the master to the slaves in a daisy chain fashion. So on the master you should have 2 terminals for the slave bus, these need to be connected to the 2 terminals on the slave bus in connector. If you have more slaves then they would be connected from the slave bus out terminal to the slave bus in of the second slave, etc.

The master bus returns data from the slaves back to the master. On the slaves there are 2 sets of master bus terminals. One set needs to connect to the master bus terminal on the master, again with 2 wires. It doesn't matter which set you use on the slave, if you look closely you will see that the master bus is all connected on parallel. The other set of master terminals would go to additional slaves. Another thing about the slave bus is there was an interference issue, this was solved by powering it seperatly from 3 AA batteries. Peter expained how to connect this up in the threads.

If you already have a built up switch then 2 wires from the switch connect to the master. I can't remeber the exact pinouts for this, if you can't find it I can look it up possibly tomorrow or at the weekend, let me know.

There is a test routine built into the master that causes each slave to flash it's led in turn. This is handy for diagnosis, if you can get this to work than you know the slave bus is working correctly.

Hope that helps,
Greg Fordyce

Daewoo Matiz
http://www.evalbum.com/4191

glyndwr1998
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Re: 16 Cell Multi Slave Board

Postby glyndwr1998 » Thu Nov 05, 2015 7:15 pm

Thanks Greg,

That's a great help. I'll wire it up tomorrow and see how it works out.
You did supply me with a built up switch too thanks, I'll have another browse on the thread to see if I can make out which pins the switch occupies on the master pcb. Also the issues with the battery power, how to implement that fix.

Thanks again Greg. If I cannot find the info I need on the thread, I'll post back for additional help.

Cheers. Anthony.

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Re: 16 Cell Multi Slave Board

Postby GregsGarage » Fri Nov 06, 2015 10:19 am

Anthony,

Peter and I designed the master software for use in a electric vehicle. You will need carefully examine the code and make changes so it is suitable for your application as a battery bank for photovoltaic panels. In particular you need to find out what the manufacture of your cells recommends when using them in an environment where they will be exposed to long periods of float charge. This is a much different application than in an electric vehicle where the cells are first charged and then discharged. The charger cut-off voltage in the existing software is much to high for cells being float charged and will ruin your cells or possible lead to cells catching fire. For a prototype project I would recommend your battery bank is placed in a location so that a fire isn't able to spread to surrounding property, see my lithium fire thread in the all things battery related topic. Another limitation of the existing software is that it requires the driver of the vehicle to stop when the cells are discharged. You will need to implement an automatic cut-off feature for charging and discharging.

The existing software is provided free of charge (see license conditions in source code comments), it is the responsibility of the end user to make sure it is suitable for their requirements. In this application you will need to make changes to the software for it to work in your application. The source code is available in the forums and is well documented so it should provide you with a good starting basis.

Greg
Greg Fordyce

Daewoo Matiz
http://www.evalbum.com/4191

glyndwr1998
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Re: 16 Cell Multi Slave Board

Postby glyndwr1998 » Fri Nov 06, 2015 10:39 am

Hi Greg,

Thanks very much for the advice it is very much appreciated.
Although the battery bank is for energy storage solution, the way I am going to use it is very similar to the way an ev works.

I shall be using a meanwell sp48/750 power supply to charge the battery from mains electricity ( not directly from solar ). I shall be using the bms as a monitor system and occasional balance charge system if any drift occurs over time. At all other times I shall have a programmable combi volt meter to relay cut each cell at 3.5v and 2.8v. So in effect I shall mostly be using the bms as a monitor. When I need a balance I could either manually balance or use the bms to balance after over riding my other controls.
The battery will be plugged into a 6kva ups that is set to operate at 48 v. I have completed several cycles of charge / discharge already and all is working ok, I thought been as I have this equipment why not use it, but it won't be used to its full potential, it'll be a good visual indication on cells that are high / low.

Many thanks for the input , it's very much appreciated.

Anthony.

glyndwr1998
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Joined: Wed Mar 06, 2013 12:34 pm

Re: 16 Cell Multi Slave Board

Postby glyndwr1998 » Sat Nov 07, 2015 7:12 pm

Hi Greg,

Is there any chance anyone could point me in the right direction of setting up the master / cell boards.

I only intend using 1 16 cell slave board, but of course this kit was being used by Greg in his ev.

So, I need to set up the bms for only 16 cells, and I have no idea how to wire up the switch or how to command or use the switch.
I have read through many many pages of the old and new bms pages plus software pages, I've found reference to the switch and a jpg of the switch built up on the switch board but not how to connect it to the master board, which pins the 3 wires from the switch connect to

Also, any reference how to use the switch.
Will the switch allow access to the program to alter the number of cells manually via the switch without having to reprogram the master board.
Any help greatly appreciated.
Anthony.


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