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Ok, I see they are very different ?

They are different?

What port on the JK BMS are you using?

Hi All, I have written some software that monitors the parameters from a jk bms using an ESP32, all is good and working well. The only problem is I'm using the GPS port that is TTL and suseptable to noise, I could fit a TTL to rs485 converter then another at the esp32 end but I noticed the...

You can also start the BMS with a multimeter. Set meter to "diode test", positive (meter) to battery negative, Negative (meter) to load negative.

That looks the business. Here is one I'm looking to buy for a lab power supply/charger. 0 to 60V, 18A, wifi, graphing function. https://shp.ee/u926svn

Non off the SMPS we are discussing have CC but do have a crude form of SC protection. Back feed protection is already built in (see the schematic posted a few threads back) basically it's a half wave rectifier fed from the isolated side of the main transformer.

That's interesting, the PWM SCC is based on switching max volts and current from the source on and off as quickly as possible that then achieves a so called ideal (average) evel to charge the battery? The major problem here is there are huge current spikes when the PWM duty is active, this...

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The SMPS potentially will make a different noise under load and the noise level depends on the quality of the build. I have on a couple of occasions taken the real noisy ones apart then use an insulated tool to "press" on any inductor/transformer in there. If the noise reduces then get your...

Yes we know that. The SMPS is feeding it's output into a PWM SCC, because the. SCC is pulsing (PWM) into the battery then the question was how does this affect the output of the SMPS? There will be some effect like increased ripple? On the SMPS. If he were to use a MPPT SCC then there would...

Yes it will if you start modifying the feed back circuitry and potentially upsetting other parts of the SMPS........definitely NOT recommended........fizz, poff, bang with smoke springs to mind ?

I would certainly not want the SOC algorithm to reset at zero ( user definable). It would seem safer to know how many AH have been used in the charge process to bring the battery to the top knee, this feels safer. Anyway, once I have my JK BMS logger finished then I can determine where these...

Theoretically the lithium load is a MASSIVE capacitor that will more than sink any spikes from the SMPS/SCC PWM coupled with the fact that the SMPS has short circuit protection. I'm guessing even the SMPS will be ok.........but don't take my word on that ?

Is there a PC app for logging the JK BMS data via RS485/BT? Googling come back with ESP home that appears to be an add on to home assistant? i have some ESP32 modules at hand so perhaps ill take that route?

Yes, totally agree on that. Perhaps the JK bases the synchronization when the "top knee" kicks in at near to full charge? Im on putting together another 4 of these battery's, these new ones use grade A LF105 EVE cells direct from the factory...............no more grade B cells with untraceable...

The BMS I'm using in the prototype battery I make is JK 2A24S JK-B2A24S20P, 6 passenger, commercial E-Trike.

Here is a technical paper from Analog Devices that's worth a read. So from my understanding and to be as brief as possible................. For coulomb counting it does indeed periodically need to re-estimate the SOC based on either the OCV after a rest period (possibly the end of charge) OR on...

Trying to figure out how the SOC algorithm works on JK BMS as well as others.

It would be nice to know how their SOC algorithm works. It must partly be based on some user settings like battery capacity and I would have thaught some voltage window that can bring back cumulative coulomb count errors over time? I have a battery out on an EV that's cycled twice per day (24s...

It would be interesting to scope the output of the PSU while charging. All the SMPS units i have are short circuit protected so hopefully nothing unexpected happens.........you still have 2 levels of protection after the SMPS, the SCC and the BMS so at least your batteries should be more than...

PWM is not ideal as you are effectively pulse charging it, I've never used PWM for charging but just hazarding a guess. MPPT would be the way to go as it uses a buck regulator to mach the battery V. Also I'm agreed on using a 24v SMPS as the power source.

How did you get on with the controller addressing? any news on if they work OK in parallel?

JK BMS - What parameters is the SOC reset based on, is it ovpr/uvpr OR ovpt/uvpt?

For a CT your measuring the AC current in the cable, it does not matter if the cable is connected to 380V or 10V, it's the current thats important. so simply use the turns ratio, the maximum current in the primary and the burden resistor value. Ratio = 200:1 Burden resistor = 50R Primary max...

She aint pretty BUT it does the job.......................maybe i should mount it in an enclosure ;-0

Theoretically yes it would BUT......................... 1. The input voltage to the SCC (solar charge controller) would need to be 3 to 5 volts HIGHER than the battery voltage depending on MPPT OR PWM, check the specs on the SCC for that. 2. If your using a 12V SMPS then probably the highest...

Not a good idea. The SMPS is fine BUT you will need a cc/cv regulator between the battery and the SMPS unless you want to sit and watch your amp meter all day while the battery is charging and twiddling the voltage pot on the SMPS. Buy a proper charger and don't trash your battery ?

The device id's are probably the RS485 addresses, they need to be unique, 1,2,3. This maybe your crash issue.

I asked the question based on some info I read on SRNE mppt controllers. The 60A version of these have RS485 comms line between them meaning one can be a master with multiple slaves. This means to me that each controller outputs should be in sync with each other? Iv read conflicting reports of...

Hi Chad, I take it the 2 epever controllers are charging the same battery? Do these controllers perform ok when the outputs are paralleled? I'm looking at doing the same thing.