JK 4S 200A BMS

My 230Ah welded studs are good for "up to 78 inch pounds" with the screw-in studs, I stopped at a bit underneath 70. It depends on your EXACT battery type, of course.

Depending on torque wrench manufacturer....most of them want you to stay at 30% on the lower side for accurate readings. 5 Nm is enough if you using flexible bus bars. Different height and non flexible bus bars will require checking for any gap when you tight one side. This is usually l run against when called by some of my friends to figure out cells imbalance or heating bus bars. Thick non flexible bus bars and not leveled surfaces between cell terminals will give you a lot of problems over time.

I will see if I can bring Infenion BMS to the aftermarket...it will be EV level of safety and modular as someone wants to make dreams come true. Will update when i talk to some of my engineers and corporate staff. It will definitely require minimum fast-acting Class-T fuses or Pyro fuses and will require one between each bank in parallel connected to the bus terminal. And quite more software side to control various other outputs. Complexity and different age or usage of battery cells will be possible but it will require benchtop observation to see how they will work as parallel setup under load or charging.

Pulse wide modulation is clever way to control some things with off grid battery setups.

What is the wire gauge for the sense wires? I have lots of good "red" ring terminal connectors that handle 16-22 gauge but smaller than that can be a real PITA.
If they are smaller, have any of you tried to crimp them into an appropriately sized ferrule and then crimp that into a standard red or blue crimp ring terminal connector?

hwse said:

What is the wire gauge for the sense wires? I have lots of good "red" ring terminal connectors that handle 16-22 gauge but smaller than that can be a real PITA.
If they are smaller, have any of you tried to crimp them into an appropriately sized ferrule and then crimp that into a standard red or blue crimp ring terminal connector?

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They're 18-awg, and they were an excellent fit for my own "16-22 AWG" ring terminals.

There is an emergency function switch on the BMS.
Notes on emergencies：
No matter what happens to the battery, the emergency switch can be turned on to charge and discharge, allowing users to use the battery in an emergency. After the emergency switch is turned on, it will automatically turn off within 30 minutes without the user's self turning off.

Nami said:

There is an emergency function switch on the BMS.
Notes on emergencies：
No matter what happens to the battery, the emergency switch can be turned on to charge and discharge, allowing users to use the battery in an emergency. After the emergency switch is turned on, it will automatically turn off within 30 minutes without the user's self turning off.

Click to expand...

Is this a physical switch on the BMS or is it on the app?

hwse said:

Is this a physical switch on the BMS or is it on the app?

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This is a right/left switch provided in the App "control" tab. This would presumably be for running the battery at low pack voltage, for a short period of time, without actually your corresponding parameter value (the low-voltage limit at which the discharge CMOS should be disconnected.

Here is my draft test report, unless (one or more) of you guys convinces me that my unfriendly 'feelings' concerning the competing DALY and JBD BMS units are unfounded. I have a lot of experience with a DALY 200A "Smart BMS", but have never tested an equivalent JBD product - my feelings about JBD are derived form lots of posts about the devices here, by other members. So I could be wrong in these feelings.

PLEASE, PLEASE CORRECT ME WHERE I SEEM TO BE WRONG!

For convenience, I attach this as a zip-compressed "docx" which can be edited and posted back to this Thread.

rickst29 said:

Here is my draft test report, unless (one or more) of you guys convinces me that my unfriendly 'feelings' concerning the competing DALY and JBD BMS units are unfounded. I have a lot of experience with a DALY 200A "Smart BMS", but have never tested an equivalent JBD product - my feelings about JBD are derived form lots of posts about the devices here, by other members. So I could be wrong in these feelings.

PLEASE, PLEASE CORRECT ME WHERE I SEEM TO BE WRONG!

For convenience, I attach this as a zip-compressed "docx" which can be edited and posted back to this Thread.

Click to expand...

Good writeup. Time limits prevented me from a very through read so I will go back to it later. One question that I have is relating to the heat function. It sounds like the heating pad turns on at the same temperature as the charging turns off. Is there any way to set the heating function to some temp above the cutoff to cause heating without simultaneous cut in charging? If not, that would be a good software upgrade.

rickst29 said:

Here is my draft test report

Click to expand...

You should indicate what version and platform the app you are using is to interact with the BMS is. Some of the issues you mentioned for instance do not happen on the iOS version.

hwse said:

Good writeup. Time limits prevented me from a very through read so I will go back to it later. One question that I have is relating to the heat function. It sounds like the heating pad turns on at the same temperature as the charging turns off. Is there any way to set the heating function to some temp above the cutoff to cause heating without simultaneous cut in charging? If not, that would be a good software upgrade.

Click to expand...

The heating pad runs according to the Charge MOS State, as controlled by low-temp parameters for "shutdown" and "recovery". (It is, as you guessed, in exact opposition MOS charging State when temperatures are too low: One or the other, NEVER both, can be active.) A re-design to add the logic you describe would probably be very complex.

A long discussion follows:

Low temp "charging shutdown shutdown" state is binary, either disabling al charging or allowing the pack to be subjected to the FULL charging current limit allowed by the max current cutoff, and even exceeded for a limited time (per the "charging overcurrent recovery" parameter, a parameter which I have reduced to just one second). But LFP Battery cells should not be expected to accept high charger current at very low temperatures, and it is my opinion that a "smart" user should raise the minimum temp parameter to be somewhat higher than zero degrees.

I have set my own charge UTP at 3.5 degrees C, and corresponding recovery at 6.0 degrees. (When the battery temp probes have fallen to 3.5 C, given the choice of "all or nothing", I prefer to safely have nothing. When low-temp has occurred, but the pack has not yet been raised ABOVE 6.0 by heating, the pad continues to operate, and charging is still disabled. My reasoning for this difference is: temperature increases created by the external pad occur on the surface of the battery cells first, and need more time to propagate inside. (The BMS temp probes are attached on the cell surfaces, almost certain to read higher than internal temperatures in a low-temperature situation wihile heat is being applied.)

In my "production environment" travel trailer, the batteries packs are within insulated interior space, unlikely to reach 3.5C or lower temperatures in the camping locations and dates I actually travel. For colder garage storage in mid-winter conditions with the travel trailer's own propane heater disabled, I think that these numbers are chosen pretty well. (The travel trailer is a fancy fold down "Trailmanor", and has the Power Converter plugged in all Winter, operating at a reduced "storage" voltage level of 3.1V). In-garage temperatures will definitely be reaching sub-freezing temperatures during early AM periods next January, and it will be interesting to see if those temps propagate through the Trailer's insulated walls to actually invoke heating.

At my location, Cold AM in-garage temps are usually recovered by early afternoon. If a re-design were to be done, it would (IMO) optimally be possible to use available charging power to run the heater circuit, even while battery pack charging is disabled. But that would need significant changes in hardware, and it would create much higher build costs.

rhino said:

You should indicate what version and platform the app you are using is to interact with the BMS is. Some of the issues you mentioned for instance do not happen on the iOS version.

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Thank you, great advice! Documentation that I used "Android App Version V4.6.5" is now added at the top of my current draft (uploaded new, replacing the previous draft within Post 185.)

withdrawn

(now irrelevant 'reply' also withdrawn)

rickst29 said:

That would not meet my preferred implementation (heating starting at anything below "recovery" temperature, even though charging is still active, when charging voltage is being supplied on the mains.) You need a switch which is based on a different control connection. Your coil won't become active until the BMS falls into "charging disabled" mode.

I actually have that already, but it depends on a separate thermostat. Because the "need" is very obscure and unlikely to make a lot of difference, I'll be throwing that and connecting my heater pads to a regular automotive power Relay (coil hooked into the JK heater circuit), with the too-powerful heater pads connected on "main" 12v. For 8S, an auto/truck Relay with "24v coil voltage (widely used in trucks and busses) would be perfect.

I don't understand your emphasis on super-high impedance, the coil just has to be durable, and the power connection must be rated for a lot more than the total current of your heater combined.

It's unclear to me how that would ever terminate heating automatically.

Click to expand...

I withdraw my post
david

rickst29 said:

Here is my draft test report

Click to expand...

Another issue that I didn't see mentioned is the BMS gets stuck connected to the mobile app at least on iOS even after quitting the app. You can verify this by the red LED staying on on the BMS. It then prevents any other device from connecting to it and I've resorted to having to reset the BMS whenever I use the mobile app so that it doesn't stay connected (preventing my Raspberry Pi from connecting to it).

rickst29 said:

The 5-wire "main cord" is shown as a switched grounding connection in Nami's previous diagrams.

If heating pad current will be below 3A, and total power also below the limit on an 8S "25.8V" battery pack, the heating pad "ground" can be wired directly to the bundled 'main cord' of green wires. The black and red wires ARE NOT currently used at all: They are only present on the connector for a possible future power supply, to be designed JK. The heating pad "hot" connection, and any heating pad switch, should be left enabled at all times. The JK will enable the "main cord" grounding connection whenever the detected battery pack temperature has fallen below the 'minimum charging voltage' temperature setting of the BMS.
In my upcoming test configuration, using a single 4S battery of adequate size, I will be testing two ways. First, with a single "12v" heater pad connected directly from the +12v bus to this grounding cord. That test will run at slightly over 2A.

Then I will re-wire, using this switched grounding connection as the "coil" ground of a normally off (NO) automotive-type mechanical Relay. This Relay will have a "12V" coil (matching my 4S battery pack), although automotive-type Relays with "24V" coil voltage are readily available as well. An 8S "24v" battery pack would use one of those instead. In this configuration, the Relay "Load" terminals interrupt the permanently connected "hot" wire, which is driving two parallel heating pads @ 2A each, 4A total current. (The pads are permanently connected to the main grounding bus, outside of the BMS.) Use of the Relay supports higher current to the pads, through the Relay's "load" terminals, while using hardly any current at all to activate the coil. In my production configuration, I will have 3 heater pads.

Will your heater pad consume more than 3A? And, was this "verbal diagram" sufficient for you?

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I just got this BMS today, and am not clear as to how this heat cable bundle would connect to my pads, especially after reading your reply @rickst29 . Bundle with connector is 3 green with ring terminal and 2 separate unterminated red/black. Red and black wires are not + - ? Looked for your referenced previous diagram from Nami but unable to locate it... thanks

rhino said:

To be clear, this is what is being said CAN NOT be done?
View attachment 95538

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Many people are doing this without problem.
Andy uses 3 banks, 3 different BMS each bank, 2 different inverters no problem.
I have seen same setup locally, but he used Dalys and 3 Deyes no problem.
A nigerian did same thing with far more battery banks and 16 Deyes no problem.

I believe the problem or precaution is when the banks are of very far charge levels.
Bank 1 is 50.0V (was depleted and manually turned off at night)
Bank 2 is 55.0V (was left ON and charged up during the day)
By afternoon, Joe remembered he turned Bank 1 off last night and went back to manually turn it ON.
Bank 2 will now try to pull Bank 1 up with as much current it can give.

After all of the discussion, it is apparent that the concern was inrush current at the moment of connection when there was a large difference between the different batteries. Most of us will work to bring them to about the same voltage before connecting and the fast class-T fuse should give protection for the OPPS factor. I cannot imagine not using a fuse near each battery. In my case ABYC requires one withing 7" of the + terminal.

Assuming 4s with no very high loads.
What are the recommended voltages for the JK and different charge sources for a reasonably conservative build?

burgerking said:

Andy uses 3 banks, 3 different BMS each bank,

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Andy ALWAYS goofs on the names. Then people start using the incorrect term and wonder why they get answers from people that do not make sense. This has been pointed out to him Many Times by Several People. It is like how some people always write TEH instead of THE, or COMOPANY instead of COMPANY. Sometimes he catches it when editing and puts text on the screen to correct his misuse.

He 3 "Battery/Packs" in ONE Battery Bank.
Each Shelf = 16 Cells, 1 BMS setup with the connectors which then goes to the Pack Breaker for that pack which is then connected to the Common DC Bus Bars running up the Side of his shelf to the top.

Battery/Pack = a Collection of Cells with its own BMS. This can act as a Single Complete Battery or work in Combination in Parallel within the Bank.
Bank = 2 or more Battery Packs set in Parallel to a Common DC Bus. Can also be Series & Parallel with Care & Caution.
The Common DC Bus is "one entity" when it comes to Solar Charger Controllers, Inverters & AIO's.

At the moment I have 4 Battery Packs in Parallel within one Bank of Batteries.
Each has a JKBMS and is independently Fused.

Steve_S said:

Andy ALWAYS goofs on the names. Then people start using the incorrect term and wonder why they get answers from people that do not make sense. This has been pointed out to him Many Times by Several People. It is like how some people always write TEH instead of THE, or COMOPANY instead of COMPANY. Sometimes he catches it when editing and puts text on the screen to correct his misuse.

He 3 "Battery/Packs" in ONE Battery Bank.
Each Shelf = 16 Cells, 1 BMS setup with the connectors which then goes to the Pack Breaker for that pack which is then connected to the Common DC Bus Bars running up the Side of his shelf to the top.

Battery/Pack = a Collection of Cells with its own BMS. This can act as a Single Complete Battery or work in Combination in Parallel within the Bank.
Bank = 2 or more Battery Packs set in Parallel to a Common DC Bus. Can also be Series & Parallel with Care & Caution.
The Common DC Bus is "one entity" when it comes to Solar Charger Controllers, Inverters & AIO's.

At the moment I have 4 Battery Packs in Parallel within one Bank of Batteries.
Each has a JKBMS and is independently Fused.

Click to expand...

I am also one of those Many People. Another of his common mis-speaks is to call an individual cell a "battery". I cringe every time I hear it. My sensitivity to it must come from that fact that I write the checks for the "Errors and Omissions Professional Liability Insurance" for my Engineering Consultant company. Words matter and sometimes even inadvertent slips of the tongue can be used to hang you.

hwse said:

I am also one of those Many People. Another of his common mis-speaks is to call an individual cell a "battery". I cringe every time I hear it. My sensitivity to it must come from that fact that I write the checks for the "Errors and Omissions Professional Liability Insurance" for my Engineering Consultant company. Words matter and sometimes even inadvertent slips of the tongue can be used to hang you.

Click to expand...

So can his Assumption leading to erroneous Conclusions, I stopped watching his stuff quite a while ago.

In Any Case... I am IN COMBAT with the Freaking APP... Only the OLD ENJ Software "enjpower-bms-3.7.4.88" will install but NOTHING from that Polar Air site "https://www.pgyer.com/Cfq3" which is where the QR Scanned code takes you and is Recommended by Hankzor on their Store Site.

Nami says it should work with my version of Droid BUT it does not regardless of what I do and YES I have allowed it in Security etc.
Bottom Line, IF I am forced to buy another Damned Cell Phone because of this SINGLE APP (I only use Voice & Text, plus this ONE BT App) as I am NOT a Cell Phone Freaktoid. I was intending to do a write-up as of some quirks, foibles & tricks BUT that may not be Good for JK given this tripe.

To think I dumped $3500 worth of BMS', Solid State Contactors for THESE to replace all of my BMS... It is Bad JuJu !
Getting a Canadian Hopping Mad takes a LOT effort and I am Getting There.