☆Doesn't Support Series Connection and parallel Connection

hwse

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Jan 2, 2021
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258
Likely due to the heater(s). Will mentioned that recently in a video about the SOK heated battery.

Given my northern latitude, I plan to get the heated version. If you heat directly from the BMS, it should not create unbalance bewteen the different banks because they are all still connected in parallel. My plan was to let the BMS heat function drive a relay so that the actual load was coming from the power buss so it would be directly shared by all batteries.
 

hwse

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Jan 2, 2021
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258
It was not the 350A limit but the 5-minute limit that tripped. You can go to between 200A and 350A for up to 5 minutes. IF you go over 350A it shuts off immediately.
 

Manfredi

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Apr 17, 2022
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I plan to build a large battery bank in the 36kWh to 96 kWh @ 48V, made of 3 to 8 equal banks of circa 12kWh/each. Each bank is made of 16x EVE LF230Ah battery, using JK BMS 2A active balancer, 200A nominal current for each bank. The big battery will serve two houses, with 2x Voltronic Axpert Max 8000 in parallel (total 16kW) and a 6kW low frequency inverter used to run pumps, lathe and other tools with 1HP to 3HP induction motors. 16kW of PV panel are planned, 8kW with bi-axial tracking towards the sun, the other 8kW fixed.

The whole battery will be monitored via Junctek KG-160F, it comes with a substantial 750A shunt, I do not think that the three inverter will exceed significantly the 750A load limit at 48V. To monitor the single battery banks via JK BMS and RS-485, I hope in the work being done by user "upnorthandpersonal" in Finland: if you have time, having a look at Junctek RS-485 communication interface would be appreciated from me and suppose others :)

I do not plan to use the heating function of the JK BMS: in my case, can the JK BMS be used in parallel in each bank of this parallel big battery?
 

Alkaline

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Jul 26, 2020
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356
I have seen the JBD do over 200A for over an hour with no issues, in fact the settings allow it to go up to 230A.

JK is cutting corners using cheaper mosfets, also the 7 guage wires for 200a is on the low end, why have wires at all just put terminals.
 

hwse

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Jan 2, 2021
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258
Yes it does and you can BUT it is NOT WISE... That is there for the rare if ever occurence happens... It is NOT anything to even consider using, it's a failsafe.
I agree fully. My original point was that Andy was TESTING the first ever 4s JK sent to him for that very purpose and his objective was to push it until it tripped. He was marginally over the max discharge current and had the time set per the spec and default values for the purpose of seeing what happened when it tripped. My comment was that JK states that they can handle up to 350A for 5 minutes. What he found is that it did indeed trip but at the cost of one FET. In spite of that the BMS was still fully functioning all be it at 19/20 of its ultimate current handling capacity.

It was not a comment on the advisability of doing so.

On my build I will have a 150A class T fuse so that the fuse will limit me to below the rated capacity of the BMS to fail-safe the fail-safe. My goal is to NEVER require my BMS to do anything to save me other than the active balancing.

There is a big difference between what someone will do for the purpose of "testing" vs what is good SOP.
 

Samcat

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May 31, 2022
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I personally think that Admin of this forum should start new YouTube videos where he torture BMS to find right size fast-acting Class-T fuse so it makes easy for others to pick right hardware. He already torture battery packs by destroying them to show what is inside.
I would be happy to see him take my advice seriously.
 
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