diy solar

diy solar

SFK BMS

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cdsolar

caduceus
Joined
Dec 16, 2022
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289
Location
Utah, USA
Are the SFK BMSs actually rebranded/custom built JBD BMSs?

Are SFK BMSs compatible with Victron VenusOS/Cerbo for reporting state of charge, etc?, either natively or with something added on in SetupHelper? (Thus not needing a shunt).

Here is an example BMS, I am aware that different models may have completely different answers .... But wanted to at least give an example:

Sun Fun Kits 150A V2 4s Lithium BMS w/Bluetooth for DIY Battery Packs- Sunfunkits.com

Sun Fun Kits 150A V2 4s Lithium BMS w/Bluetooth for DIY Battery Packs- Sunfunkits.com
www.sunfunkits.com
 
Pretty sure JBD makes them, but there app will only work with the sfk devices, however, you can use the xiaoxing app or the overkillsolar app on the sfk devices. I think they have some changes to the firmware, the sfk app will not work with overkillsolar bms or standard jbd bms.

One of the features I like is they have a capacity test recorder that lets you see the details, here is mine from my v3.5 kit using the eve 280k cells (v1 or v2?): https://www.sunfunkits.com/app/ViewBenchmarkDetails?id=dc40c5fcbde5

Not sure how the victron would work you need to have an ethernetport for them maybe the new v5 kits have them.
 
Thanks. Interesting that you say the SFK BMSs will work with the Xiaoxing and Overkill Solar apps.

The doc for dbus-serialbattery, a 3rd party add-on to Victron VenusOS, suggests that it will work with BMSs that use those apps....probably over Bluetooth or perhaps with an RS485 cable.....

louisvdw.github.io

Supported BMS | dbus-serialbattery

Currently supported
louisvdw.github.io louisvdw.github.io

I can't be the first to ask this ... Hopefully someone will chime in.

I did ask SFK, and they say their upcoming hub will allow:

BMS->(RS485 cable or Bluetooth)->hub->(canbus cable)->Victron Cerbo

For up to 4 batteries via RS485 and 4 via Bluetooth

But if dbus-serialbattery lets me do it now without the extra cost, so much the better.
 
I think it’s actually the same parent BMS company that makes JBD/Overkill and SFK units, not just JBD.

I had chatted with SFK about their JBD 200a BMS mount, which I bought a preproduction prototype (it’s pretty nice) and he mentioned some name that was the parent company, he just tossed up some specs that were slightly different than the JBD units but looked 100% the same and slapped SFK on it.
 
740GLE said:
I think it’s actually the same parent BMS company that makes JBD/Overkill and SFK units, not just JBD.

I had chatted with SFK about their JBD 200a BMS mount, which I bought a preproduction prototype (it’s pretty nice) and he mentioned some name that was the parent company, he just tossed up some specs that were slightly different than the JBD units but looked 100% the same and slapped SFK on it.
Click to expand...
Yes, I think you are correct, they are modified JBD, and I think it will work with dbus-serialbattery on Victron, either direct with RS485 or via Bluetooth. I doubt they have changed the protocol. Would be nice to have confirmation though. If not, I'll just rely on voltage. SFK has an optional RS485 port, so as long as they do not remap pinouts like EG4 seems to do, it will be an easy test.
 
diysolarforum.com

Victron VenusOS driver for serial connected BMS - JBD / Daly / ANT / JKBMS / Heltec / Renogy / Tian / ECS

I have created a VenusOS driver that can talk to BMS/Batteries that has serial communications (instead of the normal CANbus). RS485/RS232/TTL/UART and Venus 2.80+ have been tested. Currently it works with JBD BMS (LLT Power / Overkill Solar) Daly BMS (Daly Smart BMS / Daly Sinowealth based...
diysolarforum.com diysolarforum.com

works but you have to flash the cerbo with the louisvdw driver.

SFK has been supposedly working on a wireless to canbus pipe dream for a few years and looks like they eventually throw in the towel and now just added the rs-485 data port.
 
Sam Cho TX said:
One of the features I like is they have a capacity test recorder that lets you see the details, here is mine from my v3.5 kit using the eve 280k cells (v1 or v2?): https://www.sunfunkits.com/app/ViewBenchmarkDetails?id=dc40c5fcbde5
Click to expand...

Sam you seem to be very buddy buddy with the SFK folks, why don't you ask them to open the app up or at least this data recording portion to overkillsolar and other bms. Seems a little bs-ish if other apps can be used on the SFK but the SFK app won't work on others.

I wanted to try this data recorder on my overkill solar 8s but the app would not scan the device.
 
Alkaline said:
diysolarforum.com

Victron VenusOS driver for serial connected BMS - JBD / Daly / ANT / JKBMS / Heltec / Renogy / Tian / ECS

I have created a VenusOS driver that can talk to BMS/Batteries that has serial communications (instead of the normal CANbus). RS485/RS232/TTL/UART and Venus 2.80+ have been tested. Currently it works with JBD BMS (LLT Power / Overkill Solar) Daly BMS (Daly Smart BMS / Daly Sinowealth based...
diysolarforum.com diysolarforum.com

works but you have to flash the cerbo with the louisvdw driver.

SFK has been supposedly working on a wireless to canbus pipe dream for a few years and looks like they eventually throw in the towel and now just added the rs-485 data port
Click to expand...

Alkaline said:
diysolarforum.com

Victron VenusOS driver for serial connected BMS - JBD / Daly / ANT / JKBMS / Heltec / Renogy / Tian / ECS

I have created a VenusOS driver that can talk to BMS/Batteries that has serial communications (instead of the normal CANbus). RS485/RS232/TTL/UART and Venus 2.80+ have been tested. Currently it works with JBD BMS (LLT Power / Overkill Solar) Daly BMS (Daly Smart BMS / Daly Sinowealth based...
diysolarforum.com diysolarforum.com

works but you have to flash the cerbo with the louisvdw driver.

SFK has been supposedly working on a wireless to canbus pipe dream for a few years and looks like they eventually throw in the towel and now just added the rs-485 data port.
Click to expand...
I plan on using a Raspberry Pi with VenusOS, and have no problem with getting the dbus serial battery software installed. Thanks for the info that it should work..
 
The v5 kit or the v4 with the gen 2 switch so you can turn the active balancer on or off or set it to turn on when the battery is full. Also JBD can be hacked via bluetooth so being able to turn bluetooth off is a big safety feature.

Sunfunkits are supposed to be sending me an upgrade kit so I can put the gen 2 switch on my active balancer. I built a v4 kit with cells from 18650batterystore

diysolarforum.com

My build thread with LF280K from 18650batterystore and Sun Fun Kits sfk v4 Heated Kit

Hello, I would like to share with you my battery build, after seeing videos on Nate's DIY youtube I decided to do the same: I chose cells from 18650batterystore the LF280K grade A, and the standard heated kit V4 with heating. The total cost for cells was $644 delivered to Virginia and $373...
diysolarforum.com diysolarforum.com
 
That definitely looks like a JBD to me. If you go on there AliExpress store, you can get custom ones, with custom specifications made if you buy them in bulk.

All of my in use BMSs are JBD, and I have a few Dalys. Never had a single issue with the JBD's. They make a good product.
 
Alright, folks... *very* long time since I've lurked here, but finally time to get my 5 kilobucks worth of Michael Caro Lishen's into actual projects... btw, I'd not read up on the Caro saga in several years - Do I remember correctly I'm one of the lucky ones who actually got their cells? Unboxing 3-4 years later, all cells still appear to be in good shape w/consistent voltage and no swelling... whew!

Anyway, I'd bought 104ea 150Ah cells due to availability, and am now looking at various kit options. My 3 projects will be as follows:
- One 12V to add a dual battery setup to my GX460 (w/spiffy new X2 AGM) overlanding build. I'd long ago ordered a Daly 300A BMS for this.
- Four 12V's w/MPP LV6548 for home backup (currently have cells only)
- Eight 12V's w/MPP LV6548 for buddy's RV setup (currently have cells only)

I'm doing the overland build first to get some fluency on the kit options. I'd found the SFK kits and have seen the mixed feedback here, so of course, am open to other options/suggestions.

So, a few initial questions:
- How best might I make the SFK (or other) kits/brackets work with my 150a cells and Daly 300A BMS? I see they're obviously intended for 272/280Ah cells.
- I realize the Daly is overkill and even a 200a would cook it long-term, but the intention is to have headroom if I'm looking to start a compressor or other high-induction motor load.
- With my older Daly, fair to assume I'd need a separate controller/module if I want freeze protection?
- My thermo b/g tells me the inter-cell heat plate method would be the most efficient, but I maybe won't have room if I need to add isolation for twice as many cells? Either way, sounds like I'd want a newer kit version with more room, per Off-Grid Garage linked above?

I'll take whatever I learn on this build to move on to my next project, likely w/o heat, and then buddy's RV project, likely with heat (he's often in the mountains)

Suggestions for ordering from SFK or other suppliers are welcome!
In any case (pun intended muahahaha), TIA everyone!

Maybe I should have made this its own thread??

PS - Sam Cho, I see we're virtually neighbors... think maybe I'd even reached out a long time ago. Would love to buy you lunch/coffee/beer and pick your brain in any case... sounds like you've got a lot of fun things going on!
 
A.Justice said:
That definitely looks like a JBD to me. If you go on there AliExpress store, you can get custom ones, with custom specifications made if you buy them in bulk.

All of my in use BMSs are JBD, and I have a few Dalys. Never had a single issue with the JBD's. They make a good product.
Click to expand...
Again it’s the same manufacturer but slightly different brand or twist to SFK specifications vs say a JBD or Overkill.

Kinda like the crappy years of GM before bankruptcy. (Not the current crappy years where people don’t buy their product)

That Pontiac, Chevy, Oldsmobile, Buick were all the same car but slightly different, but still manufactured by GM.

I also have no issues with my JBD and would think this SFK speced unit would hold up just fine if you wanted to support that company.
 
Nikolai said:
Alright, folks... *very* long time since I've lurked here, but finally time to get my 5 kilobucks worth of Michael Caro Lishen's into actual projects... btw, I'd not read up on the Caro saga in several years - Do I remember correctly I'm one of the lucky ones who actually got their cells? Unboxing 3-4 years later, all cells still appear to be in good shape w/consistent voltage and no swelling... whew!

Anyway, I'd bought 104ea 150Ah cells due to availability, and am now looking at various kit options. My 3 projects will be as follows:
- One 12V to add a dual battery setup to my GX460 (w/spiffy new X2 AGM) overlanding build. I'd long ago ordered a Daly 300A BMS for this.
- Four 12V's w/MPP LV6548 for home backup (currently have cells only)
- Eight 12V's w/MPP LV6548 for buddy's RV setup (currently have cells only)

I'm doing the overland build first to get some fluency on the kit options. I'd found the SFK kits and have seen the mixed feedback here, so of course, am open to other options/suggestions.

So, a few initial questions:
- How best might I make the SFK (or other) kits/brackets work with my 150a cells and Daly 300A BMS? I see they're obviously intended for 272/280Ah cells.
- I realize the Daly is overkill and even a 200a would cook it long-term, but the intention is to have headroom if I'm looking to start a compressor or other high-induction motor load.
- With my older Daly, fair to assume I'd need a separate controller/module if I want freeze protection?
- My thermo b/g tells me the inter-cell heat plate method would be the most efficient, but I maybe won't have room if I need to add isolation for twice as many cells? Either way, sounds like I'd want a newer kit version with more room, per Off-Grid Garage linked above?

I'll take whatever I learn on this build to move on to my next project, likely w/o heat, and then buddy's RV project, likely with heat (he's often in the mountains)

Suggestions for ordering from SFK or other suppliers are welcome!
In any case (pun intended muahahaha), TIA everyone!

Maybe I should have made this its own thread??

PS - Sam Cho, I see we're virtually neighbors... think maybe I'd even reached out a long time ago. Would love to buy you lunch/coffee/beer and pick your brain in any case... sounds like you've got a lot of fun things going on!
Click to expand...

The only 150a cells that fit the SFK kits are the rept cells which I don't think they are selling, that or the eve 105, They are using 8 cells. I think you would end up doing a good bit of diy-ing to get there kits to work.

They are good but like you said only for the 270-304 cells and maybe the 150/105 if you want to go with 8s. I would suggest asking them if your cells will fit, I'm sure if making a 4s battery they would work may not so much on a 8s battery.

You may be better off doing a cutting board + rods type build as those appear to be quite popular as well.

one thing they got working is the victron gear comms in a recent video they uploaded, I don't have victron but I know people that do are probably happy.
 
Did anyone look at the ability of a JBD BMS to be mounted serially and create a 48V battery? The SFK BMS is a 12V BMS that can be combined serially to make up to a 48V bank. So all the components in an SFK BMS have to be 58V rated in order to do that. A lot of people have fried 12V BMSs by combining them serially.
 
Sam Cho TX said:
The only 150a cells that fit the SFK kits are the rept cells which I don't think they are selling, that or the eve 105, They are using 8 cells. I think you would end up doing a good bit of diy-ing to get there kits to work.

They are good but like you said only for the 270-304 cells and maybe the 150/105 if you want to go with 8s. I would suggest asking them if your cells will fit, I'm sure if making a 4s battery they would work may not so much on a 8s battery.

You may be better off doing a cutting board + rods type build as those appear to be quite popular as well.

one thing they got working is the victron gear comms in a recent video they uploaded, I don't have victron but I know people that do are probably happy.
Click to expand...

Appreciate the thoughtful reply... and a great point on sizing, but triple checking last night, the 104 cells I got from Michael Caro could be said REPT cells then, as they're exactly half thickness of the 272-304's @ 203h x 173w x 36.5d. So in theory they should fit the RFK's, no? If so, I'd lean towards trying the $195 v4 w/heat pads.

Guess I'd then need something really thin for spacers going 2p4s, as their 1.0/1.5mm ones would be too much. Any generic super-thin options folks are using?

Any other downsides to going 2p4s on this, or on the future 48V islanding/RV builds, 32/64 cells, respectively? I've since found the various 48V build boxes from Seplos, which I'm hoping might easily adapt to my "double cell" situation for said islanding project.

I also noticed my 300A Daly is the gigantic fan version, so would need something more compact for the SFK/overland build. What's the best supported 200A unit of those they list? This looked decent for $65: https://www.aliexpress.us/item/1005003929839501.html

And lastly, generally any pros/cons to Uart vs. U485 for iPhone, Renegy One, or MPP LV6548 connectivity/mgmt??

Thanks!
 
hello, I would like an explanation on 2 jkbms the new ones in parallel the soc is 100% AND ITS LOAD ANYWAY!!! I SPECIFY THAT I HAVE PUT ANDY’S CONFIGURATIONS!
IMG_3890.JPG
 
the slave bms loads more than the master!!! then which are at 100% and which exceed the absorption value
 
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