diy solar

diy solar

BYD BMS

bhavin66 said:
i am trying to understand this process. i think when you say no cut means you are just diverting the connection via a different connector to the factory connector on the front plate?
i ordered
43025-1000 (https://www.molex.com/molex/products/datasheet.jsp?part=active/0430251000_CRIMP_HOUSINGS.xml)
43030-0001 (https://www.molex.com/molex/products/datasheet.jsp?part=active/0430300001_CRIMP_TERMINALS.xml)
43020-1001 (https://www.molex.com/molex/products/datasheet.jsp?part=active/0430201001_CRIMP_HOUSINGS.xml) thinking i will solder the battery terminal output and get it outside and use the other connector end to mate with 16S active balancer. obviously this seems to be the wrong connector or i missed ordering the terminal for this.
Click to expand...

NOOOOOO!!!!


IMG_20200107_135349988.jpgIMG_20200107_142306197.jpgIMG_20200107_142312729.jpgIMG_20200107_142339038.jpgIMG_20200107_142451441.jpg

For the internal connector:
Not Molex parts, Tyco parts, or just 8 breadboard jumpers "might" work. I have some ordered, but somewhere in the mail.

  • 1318772-2 12POS 2.2MM Tyco Electronics Header
    • This is the OEM connector on the BYD BMS
      • I think I can do the same thing in the V2.0 parts list without this, using breadboard jumper wires.
  • 1318745-2 32POS 2.2MM Tyco Electronics Header
    • This is the OEM connector on the BYD BMS
      • I think I can do the same thing in the V2.0 parts list without this, using breadboard jumper wires.
  • USB 1.1 9pin header connecting the 12POS to the 32POS
    • If breadboard jumper wires work, this won't be necessary either. (I'll know as soon as the jumper wires get here)
You are correct. Just diverting the wires is all that is happening.
 
bhavin66 said:
i have not but working on wiring up the setup soon maybe in a week or two. i was trying to get pointers from @jasonhc73 to see if i need to keep anything in mind as my setup will be similar but with 2 batteries to start with and 2 more coming in a few weeks.
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ok,thanks.
 
@jasonhc73 Thank you for posting all this. I hate hate hate connectors and $$$crimpers I have to many.

None related I still havnt found any info on the temp voltage sensor thing used. and the data sheet for the main chip on the bms is for OEM's only tried to get a few people to get it.

I need a replacement stock BYD PCBs to BMS if anyone trashes one. One of my units the fan was eating the wire harness.
 
bhavin66 said:
i have not but working on wiring up the setup soon maybe in a week or two. i was trying to get pointers from @jasonhc73 to see if i need to keep anything in mind as my setup will be similar but with 2 batteries to start with and 2 more coming in a few weeks.
Click to expand...
how long did it take to receive your byd batts after you ordered them?
 
This might help us understand how to connect the BYD side to the black Molex connector on the BYD fan panel.

If you crimp your wires your self, use this Molex Micro-Fit 3.0. If you buy precrimped wires you can get by fine with the Molex Micro-Fit 3.0 that does not have the white Micro-Fit Terminal Position Assurance (TPA) Retainer.
IMG_20200112_100127974.jpg
This is how I color coded it to match everything up (it's also how pretty much all rainbow wires are ordered)
IMG_20200112_100345578.jpg IMG_20200112_100451606.jpg
On the Battery Pack, you will see the plug for this housing. This housing is on the BYD BMS. (You should have already taken the BYD BMS out of the pack and made a coaster with it)
IMG_20200112_100908993.jpg
Looking at the BYD Pack, with the BIG + on your LEFT and the BIG - on your RIGHT.
The first 3 sets of connectors on the left have nothing on the plug. The next 4 sets of wires are the pos (+) sensors/wires to the cells. All the rest are something else (probably temp sensors), they are irrelevant.
IMG_20200112_101058926.jpgIMG_20200112_101058926-2.jpg
This plug on the fan panel of the BYD PACK, it has tricky wiring, they switched the wires around. It's not that big of a deal.
IMG_20200112_101342131.jpg IMG_20200112_101605516-3.jpg

Remember, the only thing you are wanting is a way to connect the Molex on the outside to the cells.
You can accomplish that with breadboard jumpers. I am waiting on a slow boat from China to get longer breadboard jumpers to make sure these work. I know they will work individually, but it's a small area and I want to be certain.
IMG_20200112_101712314.jpg

I got Tech Direct Club to offer their 8s Wiring Harness Adapter by itself. It's not quite as elegant as going through the Molex connector, but it's plug and make work also. https://www.techdirectclub.com/byd-lfp-8s-wiring-harness-adapter/
 
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Ordered 3 preassembled units (w/130a BMS and shell, fan removed) from TechDirect on 1/9 after a long and helpful conversation with them. Estimated delivery in 7-10 days. They appear to be assembling them as they go according to demand.
www.techdirectclub.com

BYD LFP 24V 5 kwh 200 Ah Battery Pack With BMS 130A LiFePO4

info@techdirectclub.com
www.techdirectclub.com www.techdirectclub.com
They said not to depend on the temp protection in their BMS - which I did not plan on doing anyway - as it is listed at 90c. I will put them into service after an initial matching charge at 20amps with this charger.
https://www.ebay.com/itm/223739818200
My plan is to evaluate batteries once in use while waiting for a consensus replacement plug & play BMS (w/remote cell level monitoring) from this forum.
Comments welcome on units, charger specs and methodology.
 
GVSolar said:
Ordered 3 preassembled units (w/130a BMS and shell, fan removed) from TechDirect on 1/9 after a long and helpful conversation with them. Estimated delivery in 7-10 days. They appear to be assembling them as they go according to demand.
www.techdirectclub.com

BYD LFP 24V 5 kwh 200 Ah Battery Pack With BMS 130A LiFePO4

info@techdirectclub.com
www.techdirectclub.com www.techdirectclub.com
They said not to depend on the temp protection in their BMS - which I did not plan on doing anyway - as it is listed at 90c. I will put them into service after an initial matching charge at 20amps with this charger.
https://www.ebay.com/itm/223739818200
My plan is to evaluate batteries once in use while waiting for a consensus replacement plug & play BMS (w/remote cell level monitoring) from this forum.
Comments welcome on units, charger specs and methodology.
Click to expand...

my plan as well,i ordered 2 on the same day.
i like your battery charger idea,
 
Thanks. Let me know how yours plays out. That charger seems to have a good variable LFP charge protocol for initial conditioning (as if I knew anything for sure).
 
i most certainly will.
what part of the country are you in?
i am in Northern Virginia.
 
@GVSolar in my playing with these BYD's your going to want a charger you can adjust the output voltage on. above 28v i start to see a good amount of drift with the cells. 29.2 is going to be on the upper upper end of fully charged.
 
DHL says my wires will be here Tuesday!

Maybe go to a club instead...


C'mon really, nerds, I'm gonna be playing with wires and batteries!
 
Picasso: My plan was to use that particular charger only for the initial matching charges on the BYD's - I wanted all 3 batteries to have identical charge profiles before I put them into service in my AC & DC coupled system. That charger seemed to have a good balance of amperage & features. My DC system can get up above 60 amps @24v - and once the rest of my AC coupled panels are installed I could see combined peak currents as high as 160 amps - hence the 3 parallel batteries - rated at 130a each. The charging profiles (using Schneider Conext system components) will be set around 26.8 high and 25.8 low - 6 min absorb - between the knees.
 
*USE AT YOUR OWN RISK* discharge until you see the cells start to drift over 100mv, do the same for fully charged. average between the packs, use those points for charge / cutoff. can also push it more if you want the bms to do some of the work. 5 of my packs stay within 25mv for the cycle setting it up like that. Im still playing with the low side I have one super good pack that seems to drags the most positive cells up. High side has been good to me @27.4 and 27.8 if I want the BMS to work a little. I started with 1 BYD and have just been adding them on the top of the charge in parallel.

Edit: @GVSolar @nwillitts When you get those prebuilt units please take off the cover and show some pics of the pack. I suspect the techdirect guy is holding some of the newer packs for such use and trickling the others out to these sub retailers....? I like a good conspiracy. But I bet you nickle you guys will find the single stud cell style.
 
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will do picasso.
single stud cell style?
good or bad?
 
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