BYD BMS

[ytwytw]

I have not received them as yet - don't expect them for at least a week. Here are photos that I asked TechDirect to provide for me before I purchased.
View attachment 5019View attachment 5020

This looks really nice and they are on wheels too, how much did you paid in total? how much for shipping?

 

[Picasso]

here is my post on the two styles of BYD cells.

BYD 24V LiFePo4 Battery Modules

I am buying three of the BYD 24V battery modules, picking them up next week from batteryhookup store. According to the specs, it works with standard 24V systems (I have a MPP Solar 24V Hybrid Charger Inverter so sounds perfect to me) NOMINAL VOLTAGE IS 25.6V FULLY CHARGED IS 29.2V FULLY...

diysolarforum.com

 

[michael d]

I ordered the BYD batteries today. they had a discount of 7 percent on their website. from tecdirectclub.com free shipping

 

[maxx123]

I do like the casing, except there is no fan, I see they tossed it. 130a bms on a 200a battery? assuming light loads,

 

[solst1ce]

subscribe

 

[jasonhc73]

Minor update.
The wires I ordered got lost in the mail. I ordered some more and should be here in 3 or 4 days.
And this drawing I am finishing up...

High Res Drawing.
The other pictures.

 

[GVSolar]

Man, you are a talented human being. Thanks on behalf of all.

 

[maxx123]

here is my post on the two styles of BYD cells.

BYD 24V LiFePo4 Battery Modules

I am buying three of the BYD 24V battery modules, picking them up next week from batteryhookup store. According to the specs, it works with standard 24V systems (I have a MPP Solar 24V Hybrid Charger Inverter so sounds perfect to me) NOMINAL VOLTAGE IS 25.6V FULLY CHARGED IS 29.2V FULLY...

diysolarforum.com

two completely different battery cells wow,

 

[Picasso]

two completely different battery cells wow,

And I think that answers the question if that is just two studs exiting the cell connected internal, for the dual stud design. the mold dates on the single stud are late 2016

 

[jasonhc73]

Complete harness for the external part (1 down, 1 to make look like this, and 2 more to make).

You can use both types of Molex Micro-Fit 3.0. If you don't have pre-crimped wires, white Micro-Fit Terminal Position Assurance (TPA) Retainers. (Scroll up for the part numbers)


This is the other end, for my 16S BMS. (These connectors and wires come with the BMS)


For a DIYer, it is very satisfying to do this. I would expect these to be in the $30 range for an 8S and $50 for a 16S setup. I just spent probably 4 entire hours making this. That doesn't count the time and actual cost of sourcing the connectors, wires, crimp ends or even the right tools to do this.

If you have the tools, go for the crimp it yourself way. But if you don't have the right crimper, please save your self the agony of assembly and get pre-crimped wires. You just pop them into the connector and are done.

 

[jasonhc73]

The harness and gizmo. (bms/balancer/something else)

Open the cover, remove the BYD BMS:

Plugin the "OEM" connectors with Female-Female breadboard wires

Plug-in your gizmo.

 

[nwillitts]

i got that bms today.
batts tomorrow.

 

[jasonhc73]

Conclusion:

Molex Micro-Fit 3.0
430251000 10POS 3mm Molex Micro-Fit 3.0
or
1729521001 Micro-Fit TPA Receptacle Housing WITH Micro-Fit Terminal Position Assurance (TPA) Retainer

Molex
4303000001 12" PRE-CRIMPED Molex Jumper Wires
or Crimp your own wires
Micro-Fit 3.0 Crimp Terminal, Female


TE Connectivity AMP Connectors
1318772-2 12POS 2.2MM Tyco Electronics Header
1318745-2 32POS 2.2MM Tyco Electronics Header

Dupont Wires
Female to Female Jumper Cables

The Male to Male jumper cables, sort of work, but are very loose. If you are comfortable with them, you do not need the TE connectors.

The Molex connector on the BYD fan panel:
The connector has pretty much no standard on the backside. I have 3 different ways it is wired on my BYD batteries. Use the jumper cables to the outside panel.

The only thing that is standard, is the fan 24V position on the far left.
24V R B B B B
24V R B B B B
or
24V B B B B R
24V B B B B R
(nevermind this, just look at the pictures a few posts after this)

It's just a color and a connector. Connect the jumpers so the Molex Connector on the outside is
_ 7 5 3 1
_ 8 6 4 2


Wires on the battery side on my BYD's are the same for all 8.
- - - 7 5 3 1 ---------
- - - 8 6 4 2 ---------

 

[nwillitts]

thanks for all you do,Jason.
my hat is off to you.
thats a lot of work.

 

[GVSolar]

Indeed. You are a most resourceful fellow.

 

[jasonhc73]

 

[shorawitz]

The harness and gizmo. (bms/balancer/something else)
View attachment 5686 View attachment 5687
Open the cover, remove the BYD BMS:
View attachment 5688 View attachment 5689
Plugin the "OEM" connectors with Female-Female breadboard wires
View attachment 5690 View attachment 5692
Plug-in your gizmo.
View attachment 5693 View attachment 5695

It looks like you're just manually connecting the cell monitor to the main negative somehow. Any thoughts on wiring that in to the connector?

 

[jasonhc73]

The external connector has 10 spots. I left the last two for the fan. That leaves no spots for a connection to the minus.

 

[jasonhc73]

If you happen to get this problem;
1st cell not showing the right V;

Verify that you really do have the right voltage of the cells with another checker. This is an ISDT Battgo (Amazon Link).


If you verify that you really do have normal voltage, then make sure your BMS has all the wired connected properly, specifically the negatives. If you have the screen, you better have two wires going to the negative terminal.



After you put the 2nd wire back onto the battery, find the culprit and beat them without mercy with wet noodles!

 

[JeepHammer]

Good "Help" is hard to find...

Thanks for all this Jason.

 

[yocor103086]

The external connector has 10 spots. I left the last two for the fan. That leaves no spots for a connection to the minus.

What are you using to power the fan? Just an external supply? You could connect the common of your fan supply to the common of the battery. Then you only need 10 spots.

 

[jasonhc73]

What are you using to power the fan? Just an external supply? You could connect the common of your fan supply to the common of the battery. Then you only need 10 spots.

I don't plan on letting my garage getting above 40°C let alone 60°C or 70°C when the battery needs cooling fan running.

But my plan is to power the fan from the battery with a thermally activated switch, L 40, med 50, H 55.

 

[jasonhc73]

I don't plan on letting my garage getting above 40°C let alone 60°C or 70°C when the battery needs cooling fan running.

But my plan is to power the fan from the battery with a thermally activated switch, L 40, med 50, H 55.

And just like that, even when you don't plan to let the garage get that cold. A day like this happens:



LowTemperature BMS saves the day...

 

[Sojourner1]

Prepare for the "what if" it can save a lot of headaches.

Are you going to change or build anything to keep the batteries warmer just take this as a once in awhile cold spell?

Did the cells themselves get that cold or just the ambient temp?

 

[jasonhc73]

Prepare for the "what if" it can save a lot of headaches.

Are you going to change or build anything to keep the batteries warmer just take this as a once in awhile cold spell?

Did the cells themselves get that cold or just the ambient temp?

I am not changing anything. This is a very rare cold day in Kansas. 11°F = -11°C

Look closely at the BMS screenshot.
MOS 4°C
Balance MOS 5°C
T1 1° C
T2 2° C

T1 is on the terminal, and T2 is poked into the case.
I have the BMS set to stop at 2°C and recover at 3°C.

So to get it back going, I opened the garage door, and let the house warm up a degree in there.

This only happened on the lowest pair. The 3 pairs above where at 3°C.