JBD Bms Display

[Dadkins]

I’m looking to buy a lcd display for my JBD 7-20s 200amp bms straight from their AliExpress store. Do I need to order the “LCD- uart port” or the “LCD- RS485 port”. I would like for it to still have Bluetooth

 

[A.Justice]

Mine takes the uart, but you have to remove the Bluetooth module.

I find a dedicated shunt to be much more accurate than my BMS. I would go that route if I were you.

 

[Luk3jay]

Mine takes the uart, but you have to remove the Bluetooth module.

I find a dedicated shunt to be much more accurate than my BMS. I would go that route if I were you.

Interesting. I bought the JBD BMS with screen specifically because I thought the bms must have the most reliable SOC indication. And I must say it's been pretty good for me!

however I'm now looking at building my own electrical control system, incorporating SOC, and reading the data from the BMS is difficult. what shunt would you recommend? Thanks.

 

[A.Justice]

Interesting. I bought the JBD BMS with screen specifically because I thought the bms must have the most reliable SOC indication. And I must say it's been pretty good for me!

however I'm now looking at building my own electrical control system, incorporating SOC, and reading the data from the BMS is difficult. what shunt would you recommend? Thanks.

I have one of these, and it's within 1% of my Fluke multimeter. I also have a $100 Renogy shunt that isn't nearly as accurate. For the price, it can't be beat.

bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt https://a.co/d/i2jT53O

 

[Luk3jay]

I have one of these, and it's within 1% of my Fluke multimeter. I also have a $100 Renogy shunt that isn't nearly as accurate. For the price, it can't be beat.

bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt https://a.co/d/i2jT53O

Thanks. Unfortunately that won't work for me as i need one that can interface with other systems, or at least show history.

I'll keep that in mind for other projects though.

 

[A.Justice]

Thanks. Unfortunately that won't work for me as i need one that can interface with other systems, or at least show history.

I'll keep that in mind for other projects though.

My bad, now that you mention it I remember that you had asked for that requirement. I've been known to mix up / forget threads.

 

[ialpert]

I did try a few of the shunts and HAL sensors and they are all over. I had high hopes for more expensive Renology... Pretty much every device with a shunt or hall sensor still relies on voltage for SOC calculation and is up to 45% off what my JB BMS shows.

Question: If BMS decides the battery is empty and shuts it off, does it matter if it's accurate or not? If BMS thinks it's empty then it's empty...

 

[octal_ip]

I did try a few of the shunts and HAL sensors and they are all over. I had high hopes for more expensive Renology... Pretty much every device with a shunt or hall sensor still relies on voltage for SOC calculation and is up to 45% off what my JB BMS shows.

Question: If BMS decides the battery is empty and shuts it off, does it matter if it's accurate or not? If BMS thinks it's empty then it's empty...

SOC alone shouldn't cause the JBD BMS to shut off the load. When it reaches 0%, it just stays there and attempts to re-calibrate as the load continues to draw energy.

It's protection triggers are all based around temperature, current and cell maximum/minimum voltages.

 

[ialpert]

SOC alone shouldn't cause the JBD BMS to shut off the load. When it reaches 0%, it just stays there and attempts to re-calibrate as the load continues to draw energy.

It's protection triggers are all based around temperature, current and cell maximum/minimum voltages.

Thanks for the clarification! My application is for a golf cart and I was too afraid to let it zero while in the field... I have 105Ah Evo / 200 Amp JBD and once it goes below 40% it starts choking on acceleration. The motor pulls up to 240 amps easily...

Funny enough BMS often thinks capacity is 78Ah, not 105. It charges to 78Ah and claims 100%. A few times in the app it said full capacity is 78500, not 105000. I had to go into settings and put it back to 105Ah. My cycle capacity is configured at 95Ah and that setting stays untouched.

 

[octal_ip]

yeah, I've learnt not to trust either my BMS or inverter for SOC calculation. Both aren't accurate enough to properly monitor consumption over long periods of time, particularly at low currents. I just watch for the accelerated voltage drop as the pack discharges or call it a day once the cells are at 3.1V.

 

[Tazmadman]

Is there away to keep the screen turned on constantly ? I have the rs458 display

 

[740GLE]

Thanks for the clarification! My application is for a golf cart and I was too afraid to let it zero while in the field... I have 105Ah Evo / 200 Amp JBD and once it goes below 40% it starts choking on acceleration. The motor pulls up to 240 amps easily...

Funny enough BMS often thinks capacity is 78Ah, not 105. It charges to 78Ah and claims 100%. A few times in the app it said full capacity is 78500, not 105000. I had to go into settings and put it back to 105Ah. My cycle capacity is configured at 95Ah and that setting stays untouched.

Pulling 240a through a single string of 105ah cells or do you have some paralleled up?

That kind of current is very aggressive for a single string and single BMS