Go Back   EcoModder Forum > EcoModding > Off-Topic Tech
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-07-2018, 01:52 PM   #1 (permalink)
Human Environmentalist
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 10,403

Acura TSX - '06 Acura TSX
90 day: 28.24 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.06 mpg (US)

Chevy ZR-2 - '03 Chevrolet S10 ZR2
90 day: 17.14 mpg (US)
Thanks: 3,615
Thanked 3,881 Times in 2,920 Posts
BMS Wiring for LiFePO4

I bought some cheap Ebay BMS boards for my 4s LiFePO4 batteries that I intend to put into motorcycles. The model number is HX-4S-F100A, but I cannot find any instructions on how to use these other than the graphic printed on the label.



C- is supposed to be connected to the charger, and P- is supposed to be connected to the load. My question is, can these be connected together, since in a vehicle both the load (starter/accessories) and charge (alternator) use the same connection? I haven't found a schematic or anyone else showing how they connected the board, so I don't know if those connections can be shared.

Finally, would this board provide balancing if only the balance leads are connected?


__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-07-2018, 03:07 PM   #2 (permalink)
Corporate imperialist
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 10,333

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
Thanks: 248
Thanked 3,318 Times in 2,616 Posts
Let me know how it works.
I spent about $600 on cells for my 60ah 13v LiFePO4 batt. A BMS wouldn't be a bad idea.

It won't work unless you external charge it. You need at least 14.8v a vehicle alt will typically make 13.8 to 14.4v most make around 14 to 14.2v I have found.
I say external charge it.

I would hook the battery straight up to the vehicle charging system like normal, since you are only supposed to run 10 amps through the charger circuit. An lithium battery will take full alternator output, which will be a lot more than 10 amps, bad for the charger circuitry.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 08-07-2018, 03:25 PM   #3 (permalink)
Human Environmentalist
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 10,403

Acura TSX - '06 Acura TSX
90 day: 28.24 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.06 mpg (US)

Chevy ZR-2 - '03 Chevrolet S10 ZR2
90 day: 17.14 mpg (US)
Thanks: 3,615
Thanked 3,881 Times in 2,920 Posts
Yeah, I'll probably just experiment to see how it goes, and measure current flow given difference scenarios.

My motorcycle probably wouldn't put out too much current for the BMS to handle, but as you mention, it probably won't charge at all if it's not getting more than 14.8v. If that's the case, I'll see if it still serves a balance function. Was really hoping it could provide low voltage disconnect ability.

Maybe I'll put one of these batteries in a car, and use a small solar panel as the charge input. I'm assuming it's ok to use the charge connection and leave the load connection unused.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 08-07-2018, 03:43 PM   #4 (permalink)
Master EcoModder
 
Stubby79's Avatar
 
Join Date: Sep 2012
Location: Victoria, BC
Posts: 1,747

Firefly EV - '98 Pontiac Firefly EV
90 day: 107.65 mpg (US)

Little Boy Blue - '05 Toyota Echo
90 day: 33.35 mpg (US)

BlueZ - '19 Nissan 370Z Sport
90 day: 17.19 mpg (US)
Thanks: 75
Thanked 570 Times in 425 Posts
I don’t see it working; they make BMSs that charge through the same port as the discharge. That’s probably the right way to go.

Otherwise you could run your alternator straight to the charge port, and let the discharge port run the bike, or else throw in Diodes to speed are the one from the other....
  Reply With Quote
Old 08-07-2018, 04:01 PM   #5 (permalink)
Master EcoModder
 
teoman's Avatar
 
Join Date: Jan 2017
Location: Istanbul
Posts: 1,242

A3 - '12 Audi A3
Thanks: 65
Thanked 224 Times in 185 Posts
I recently watched a video on this.

It has a serial port and you can buy a bluetooth dongle for it.

Then there is an app for it ( or computer program and usb to uart converter) where you can calibrate it and define a whole bunch of parameters like do you want balancing while discharging or charging. It also had a input voltage cutoff if i remember correctly.

May not be ghe same one.
  Reply With Quote
Old 08-07-2018, 05:34 PM   #6 (permalink)
Human Environmentalist
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 10,403

Acura TSX - '06 Acura TSX
90 day: 28.24 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.06 mpg (US)

Chevy ZR-2 - '03 Chevrolet S10 ZR2
90 day: 17.14 mpg (US)
Thanks: 3,615
Thanked 3,881 Times in 2,920 Posts
I don't think this device has the smarts to be programmed. The diode idea sounds interesting, but would represent yet another drop in voltage that would need to be overcome to charge the battery, and they would have to be rated for large power.

I'll try to play with the BMS tonight with a solar panel and see what it can do. The thing I liked about the specs is the extremely low working power draw, so it wouldn't run down a battery that was sitting for long periods of time.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 08-08-2018, 06:43 AM   #7 (permalink)
Master EcoModder
 
sendler's Avatar
 
Join Date: May 2011
Location: Syracuse, NY USA
Posts: 2,935

Honda CBR250R FI Single - '11 Honda CBR250R
90 day: 105.14 mpg (US)

2001 Honda Insight stick - '01 Honda Insight manual
90 day: 60.68 mpg (US)

2009 Honda Fit auto - '09 Honda Fit Auto
90 day: 38.51 mpg (US)

PCX153 - '13 Honda PCX150
90 day: 104.48 mpg (US)

2015 Yamaha R3 - '15 Yamaha R3
90 day: 80.94 mpg (US)

Ninja650 - '19 Kawasaki Ninja 650
90 day: 72.57 mpg (US)
Thanks: 326
Thanked 1,315 Times in 968 Posts
Large LiFe starter batteries are very prone to stay balanced and don't necessarily need a bms if you can manually balance a couple times per year. They also have extremely low self discharge so can sit for a year without going dead.
  Reply With Quote
Old 09-12-2020, 11:30 PM   #8 (permalink)
Human Environmentalist
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 10,403

Acura TSX - '06 Acura TSX
90 day: 28.24 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.06 mpg (US)

Chevy ZR-2 - '03 Chevrolet S10 ZR2
90 day: 17.14 mpg (US)
Thanks: 3,615
Thanked 3,881 Times in 2,920 Posts
I hate when I Google something to get more info, and the top hit is my own post from years ago.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 10-10-2020, 01:45 AM   #9 (permalink)
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,705

spyder2 - '00 Toyota MR2 Spyder
Thanks: 103
Thanked 386 Times in 297 Posts
Haha, happens to me too.

Looking at the diagram, it's a charge balancing only circuit, probably has a passive means of dissipating small amounts of energy, so I think you're fine if you connect the load to the charging directly. Effect is probably identical to putting diodes that burn off excess voltage, except in a nicer package that can be connected to a trickle charger.
  Reply With Quote
Old 10-10-2020, 01:04 PM   #10 (permalink)
Master EcoModder
 
Stubby79's Avatar
 
Join Date: Sep 2012
Location: Victoria, BC
Posts: 1,747

Firefly EV - '98 Pontiac Firefly EV
90 day: 107.65 mpg (US)

Little Boy Blue - '05 Toyota Echo
90 day: 33.35 mpg (US)

BlueZ - '19 Nissan 370Z Sport
90 day: 17.19 mpg (US)
Thanks: 75
Thanked 570 Times in 425 Posts
(Dead thread, but suggestions might help future ppl)

My suggestion to anyone when picking a BMS...stick to "Two wire" BMS's unless you have a specific reason to want a separate charge line.

Two wire will behave like you're connecting directly to the battery...nothing weird screwing things up, unless you trigger the protection...

So if you're replacing a lead acid battery on, say, an e-bike, your regen will still work and not try and fry your BMS or behave like there's a diode blocking the regen. Or in a car, where the altenator is going to kick in at some point. Or anything else...

I really can't see much point to a three-wire, unless it's in a device which will only ever drain it and you need to be able to hook a charger up...but why you couldn't have it hooked up in parallel with the load/battery...I have no idea. Protection from dummies short-circuiting the charge port comes to mind, but I couldn't guarantee it wouldn't short out that way anyway.

Stick to two wire. Especially if you're not sure.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com