A couple points, if the input screws are hotter than the output screws then the terminals or mounting pads may need cleaning, both sets of terminals should be carrying the same current so I would expect the temperatures to be similar. In the App you will see there is a separate MOS temperature reading so no need to use one of the flylead sensors on the case. From memory the MOS shutdown temperature is fixed at either 70 or 90 deg C (on the second page of the App).
I have found that after torquing the screws down (by hand) , I have retorqued the screws a few months later and been able to apply more torque to screws, possibly they settle a little or sink slightly into the heavy solder at these points a little with time. From memory I think they use 20 x 180Amp MOSFETS, 10 on input & 10 output, so should be fairly robust overall. I have only setup 2 of 3 JK BMS’s I have, but I haven’t pushed mine up this high as yet on my 24v system. My guess is the hotter join in positive to inverter is where ur getting a greater loss & while the JK cables are generally on the skinny side to carry these sort of amps, they do seem to manage quite well and I thought 60 degree C was not bad for these conditions. Thanks for sharing. Cheers
Thanks Rog, this was the video I was waiting for before proceeding. I'm no expert, but guessing the the MOSFETS are under most stress when the overcurrent protection kicks in (ie disconnect when drawing above 200A). It seems that if one FET dies it spreads the load over the remaining FET (assuming it dies in the open state). Hence it may appear to still be working even after sustaining damage. It would be good to see the BMS stress tested with multiple high current disconnects. Hopefully someone with electronics knowledge can comment if its possible to test MOSFETS in circuit to see if they are all still working. Otherwise keep an eye out for the magic smoke when it switches off. Thanks again.
I bought one of these almost 2 years ago when they first came out, and mine didn’t come with the large cables for B and P. With an 8s 24v pack made of 304ah cells what size wires should I use? I’m not sure how large the bms will allow at the lug point. Thanks for all your videos they are very helpful.
the bms app do display mosfet temperature and you can change when the bms shuts down from mosfet over temperature in the app settings. I got both daly and jk bms and i think jk is much better. My JK have been going strong for 320 days now and cycled over 2 Mwh of energy. Although it is an 200A model the max current it have pushed is 100amps so it is not being pushed hard.
I watch alot of your videos. Im fixing to build my first lifepo4 battery with the 280 grade a eve cells. 16 cells and 24 volts. 2p8s. Hopefully it does good. Im wonderimg what you know about mixing battery chemistries because i have a bunch of leaf cells that are nmc chemistries. Im sure it can be done at 48 volts but im not so sure about doing it at 24 volts because the difference is to far away im afraid
@@offgrid_power the more I look into it the more I think the same. Thanks for the advice. I'm gonna keep two seperate systems running until I can afford to switch out the leaf modules for more lifepo4 and then connect all into one large bank
Why would you routnely over amp any eletrical device? I would design any system with a good margin if i want 100amps max id use components of at least 50% higher rating and where possible and practical 100% higher running everything at 50% capacity. In the case if a 4s pack 300 ish ah cells 100a output through a 200a bms works with a 3kw inverter. If i need 5 or 6kw up the cell count to 8 and voltage to 24v nominal. Amp draw remains at around 100a. Betond this id consider splitting into two separate batteries to double up then to double up again goto 2 x 16s by which time were getting upto 20kw output still only using 100a ish from 200a bms's 😮
A couple points, if the input screws are hotter than the output screws then the terminals or mounting pads may need cleaning, both sets of terminals should be carrying the same current so I would expect the temperatures to be similar. In the App you will see there is a separate MOS temperature reading so no need to use one of the flylead sensors on the case. From memory the MOS shutdown temperature is fixed at either 70 or 90 deg C (on the second page of the App).
YOU HAVE A WONDERFULLY ENGLISH NAME MILLY
Replying myself! just checked and MOS shutdown is 90 deg C and reconnect at 70 deg C, both look to be adjustable.
They are fixed. The charge and discharge temp limits and recovery temps are adjustable
good call I was going to ask what was the mosfet temperature displaying on the app
I'm running 7 ea 16S 200A versions with LCD screen. Love them. I've pushed 300A through one for a minute.
I have found that after torquing the screws down (by hand) , I have retorqued the screws a few months later and been able to apply more torque to screws, possibly they settle a little or sink slightly into the heavy solder at these points a little with time. From memory I think they use 20 x 180Amp MOSFETS, 10 on input & 10 output, so should be fairly robust overall. I have only setup 2 of 3 JK BMS’s I have, but I haven’t pushed mine up this high as yet on my 24v system. My guess is the hotter join in positive to inverter is where ur getting a greater loss & while the JK cables are generally on the skinny side to carry these sort of amps, they do seem to manage quite well and I thought 60 degree C was not bad for these conditions. Thanks for sharing. Cheers
Thanks Rog, this was the video I was waiting for before proceeding. I'm no expert, but guessing the the MOSFETS are under most stress when the overcurrent protection kicks in (ie disconnect when drawing above 200A). It seems that if one FET dies it spreads the load over the remaining FET (assuming it dies in the open state). Hence it may appear to still be working even after sustaining damage. It would be good to see the BMS stress tested with multiple high current disconnects. Hopefully someone with electronics knowledge can comment if its possible to test MOSFETS in circuit to see if they are all still working. Otherwise keep an eye out for the magic smoke when it switches off. Thanks again.
I bought one of these almost 2 years ago when they first came out, and mine didn’t come with the large cables for B and P. With an 8s 24v pack made of 304ah cells what size wires should I use? I’m not sure how large the bms will allow at the lug point. Thanks for all your videos they are very helpful.
Hi what clamp meter are you using for these tests
Where to buy the BMS? Seems to be out of stock everywhere...
What wire gauge are you using? i see the + is thicker
the bms app do display mosfet temperature and you can change when the bms shuts down from mosfet over temperature in the app settings. I got both daly and jk bms and i think jk is much better. My JK have been going strong for 320 days now and cycled over 2 Mwh of energy. Although it is an 200A model the max current it have pushed is 100amps so it is not being pushed hard.
Hi everyone
Eve LF105ah brand new cell made by 12v pack need to Balance machine or jk bms is enough?
Only problem I’ve had with mine is charging with the server style charger . It is very erratic
I watch alot of your videos. Im fixing to build my first lifepo4 battery with the 280 grade a eve cells. 16 cells and 24 volts. 2p8s. Hopefully it does good. Im wonderimg what you know about mixing battery chemistries because i have a bunch of leaf cells that are nmc chemistries. Im sure it can be done at 48 volts but im not so sure about doing it at 24 volts because the difference is to far away im afraid
Personally I probably wouldn't mess around with mixing chemistries in the same battery. I think it'll land up being a nightmare.
@@offgrid_power the more I look into it the more I think the same. Thanks for the advice. I'm gonna keep two seperate systems running until I can afford to switch out the leaf modules for more lifepo4 and then connect all into one large bank
Why would you routnely over amp any eletrical device? I would design any system with a good margin if i want 100amps max id use components of at least 50% higher rating and where possible and practical 100% higher running everything at 50% capacity.
In the case if a 4s pack 300 ish ah cells 100a output through a 200a bms works with a 3kw inverter. If i need 5 or 6kw up the cell count to 8 and voltage to 24v nominal. Amp draw remains at around 100a. Betond this id consider splitting into two separate batteries to double up then to double up again goto 2 x 16s by which time were getting upto 20kw output still only using 100a ish from 200a bms's 😮
👍👍👍👏👌