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Where is the shunt. It is typically mounted on the negative wire and can be anywhere from at the battery to the other end of the main negative wire. The WS500 gest connected to the shunt with a [12] gray and [13] purple wire but these are not the battery sense wires. The sense wires are [10]...

Excellent. Note, I am quoting voltages that I use for my system which is 12v so for a 48v you would need to multiply by 4. These numbers will not be the correct ones for every system or individual but are what I am happy with. On my system I use the "silent" final charge with the "rebulk"...

My JK is the B2A8S20P and I have never seen the FET temperature more than a 10ºC above ambient when charging with 120A which is my highest current. I have plans to add a much larger alternator to my boat which will let me charge at 190A and will be monitoring the FET temp to see how it does.

I had a Lifeline 4D in my boat and also got 7 years out of it and then it fell on its face. On the last cruise with it, the battery monitor showed that I had pulled only 70Ah of the rated 210Ah out and the voltage was at 10.2v. I replaced it with a DIY 2p4S LFP bank with 560Ah that fit...

On my motorhome, my two 460Ah packs are in the battery compartment in an unheated part of the basement. In the original configuration, this compartment was vented as required for FLA batteries. I sealed up the vents so that it would remain dry and not have wind blowing through. This past...

I connect to the input of the ArgoFET so that I do not need to worry about the voltage sensing being affected by the ArgoFET or any BMS dropout. The only downside I can see to this arrangement is that I might get a bit lower voltage than desired at the battery due to voltage drop in the cable...

I just bought a set of (8) from Docan Power US warehouse for $149. They are currently out of stock but the boat is due this week. We will see if it gets here on schedule.

Not everyone can reduce the current that their charge source sends to the battery. But for LFP almost everybody can set the absorption voltage to a custom setting. Once that is done, the charge controller will reduce the current to a level that will not send the pack above that point. I have...

On #2 I am not sure I understand your statement. If two battery packs each with their own BMS are connected in parallel at the - & + buss bars, the BMS is protecting each regardless of what the other is doing, is it not? For easy math let's assume we are using (8) 100A cells. Are you...

That button and the ability to turn it on and off at will is rather handy. Except for that time when I turned off and never turned back on.

You can add as many as you want as long as they all have max voltage less than the max allowed by your batteries. I prefer to have the "dumbest" chargers stop charging at 0.1v less than the voltage of my smartest charger so that the final charge is more controled. I use a couple of Victron 30A...

Have you watched any of Andy's (Off Grid Garage) videos on banks with different SOC connected in parallel? He was surprised by how "non-eventful" it was. I think that given the low voltage difference and the resistance in the interconnecting wires, the current is mild enough to not be a problem.

In your screen shot from post 55 you are showing a 255mv delta which is very large for a JK. It is trying to fix that by pulling 2.082A out of cell 1 but your charge controller is still stuffing 6.7A into the pack and drives #1 to OVP cutoff. To solve this, change your charge controller so...

my corner spacers allow me to fix the cells to prevent movement and create a 1mm separation which puts all of the fixture load on the corners of the aluminum cases. I have not found any cells that do not have between .5mm and 1mm of bow from corner to center when fully charged. with my cells...

Regardless of if they will hold a charge or not, they are never junk. Junk is thrown into the track but the least recycle core charge I have ever gotten for an FLA regardless of condition is $10.

They did not "Make it right" with me. I was refunded about 25% in spite of the damage. One mounting ear was bent completely back on itself and both plates were bowed outward which is crushing the outer Mosfets. It is working but I do not trust it and will replace it. If they would have used...

I cut the excess length from each of my sense wire to eliminate needing to coil or back track. My BMS would only fit on the end of the pack which was 2p4s so the shortest wire is about 5" and the longest is 24". The JK tested each wire and entered a different resistance for each without any...

According to the log file on my JK, I have hit UVP twice. Once when doing a capacity and system test. The other time was when I forgot to check my SOC and the heater ran longer overnight than expected. I have my UVP set to 3.0v so that I can lower it to 2.6v, turn off all nonessential loads...

The idea here is not to fully charge the LFP with the generator. It is used to make up for the shortfall of solar. @Sparky7 stated that he has a manual start generator that he will use with the pack gets too low due to lack of sunshine. I am assuming that he will chech to see how long he will...

I have 4.6.5 loaded but see that they now have 4.7.1. What is the difference between them and should I upgrade? Still waiting for delivery of my BMS.

I am using the 4s-8s JK BMS and it is the small cyan box mounted on the right end of the 2p4s model in Post #1. They have mounting holes in the case, and I will attach the BMS with screws to the end caps. At this time, I am hoping to make the end caps out or Starboard.

The cells will tell you when they are full. If they are still taking significant amps without the voltage spiking (no single cell over 3.65v) then the battery is not full. At 3.35v/cell, my batteries are still taking my full charge current, so they are not full. I set the chargers for...

I am getting the following error error on my 200A JBD BMS FET Software Locked It showed up after I turned off discharging just after my battery got to LVP cutoff at 2.5v on one cell. I wanted to take one of my two batteries off line which I continued the test on the other which was at a...

What model of JBD do you have that has active balancing? Every JBD that I am aware of has passive balancing in the range of 50 to 150ma which does not do much.

Got that covered. My bank is just two 460Ah packs and I use a diagonal connection with 4-0 paralleling wires. I was unable to tighten the ring terminal tightly against the batteries terminal because it is flush to the top of the case and did not provide any space for the insulation. I...

My second JK with proper sized packaging was from the "JKBMS Store".

There is a lot to unpack here but I will give it a try. [A] An alternator should never go to a higher voltage than what it is set to no matter how big the load. If the SOC (state of charge) of the battery, the alternator will put out its maximum power in Watts. For simple numbers let's say we...

That is $10/battery minimum. The recycle price is a flat $10/battery at Autozone but if you take them to a metal recycler, they give a price / lbs which can be significantly more for big deep cycles.

King Starboard™ not starboard. But to be perfectly honest, it will be on starboard along with the cells because my battery compartment is under the starboard settee so then it will be on the aft end of the battery pack.

1. were the shunt extension wires a twisted pair or shielded wire with a ground on one end? That length you can get a big emf error. 2. You do not really need rpm and it does not need to be accurate any way. that is mainly there so that you can depower the alternator on small engines so that...

I do not have any big draws, just a lot of long term draws in the 5-7 amp range. The main ones are: Refer freezer hydronic boiler, five +3A fans on heating system autopilot My daily usage is in the range of 125Ah - 175Ah so with the old 210Ah AGM. I needed to pull it down 80% and recharge...

My installation is on a boat, and I used 2 x 2-AWG to 1/4" ring terminals. They both go to a common post on my shunt. The rest of my primary wiring is 2/0 and two 2AWG is exactly the same area as one 2/0. All wire is fine stranded Anchor tinned marine wire with tinned crimp terminals.

I am not sure I follow your meaning. please tell me if I have it correct. The monitor can be linked to the BMS by Bluetooth which would disable the Bluetooth app. The monitor can be connected to the BMS by the wired connection to the "display" port which would enable the Bluetooth app to work...

I have a sailboat with a 560Ah LFP house bank. I do not have any solar, so all charging is done either by a pair of Victron Ip67 30A chargers for a combined output of 60A or my 108A Ample Power alternator. The Alternator has an external regulator and I have added 1.0Ohm of resistance to the...

When I connected my LFP to my boat, the alternator quickly went to 110ºC and I turned it off. That was why I made the modifications outlined above.

Here is the manual I got with mine. I also have a photo of the test setup for my 2p4s setup. As said above, the B- connects to the most negative terminal on your battery (last - bottom right in your photo). The P- is your negative output connection and on my system goes to my negative power...

It looks like you have made the jump to LFP. Are you planning to also keep the AGM's. It can be very tricky to design a system that will utilize both. LFP's do not require to be charged to a high 100% charge voltage on a regular basis unlike AGM which hate sitting for long at partial state of...

my understanding is that on the JK BMS, the sense wires do not need to be the same length. Is this correct or a myth? I believe that on other BMS's the sense wires need to be the same length but that the JK BMS will calculate the resistance of the wires when it does its active balance thing...

Thanks, Nami. On the heat function it seems that it is tied to the low temp cutoff, so the BMS turns on the heat at the same time it turns off the charging. Then when the BMS turns on the charging, it turns off the charge. That is less than optimal for control. It would be best if there...

I am sitting here wondering why there would be and polychlorinated biphenyls in a LFP battery system because they were banned decades ago. :eek: D'oh! PCB stands for printed circuit board. :rolleyes: Must be a generational thing.

GGRR!! I tried that an and got no farther. Frustrating. [EDIT] I finally got it to install. One of these days I will figure out hot to use a smart phone. :poop:

I wish they were selling the JK last month when I ordered my cells. I got the cells in 3 days from Houston, but it has been a month and I am still waiting for the JK from Hankzor. Yesterday, tracking indicated that it was "out for delivery" in my town but it did not show. Hopefully today.

Here is a screen shot of the updated info on the Hankzor Store. This was changed as a result of the thread that I started about this limitation and the eventual resolution from @upnorthandpersonal. I think that their engineers were thinking mostly about high load applications like propulsion...

In my opinion, the method of lowering the CV voltage to slow down charging as the JK is balancing is more effective than current limiting. When I first built my 560Ah pack, I used the current limiting technique because I did it at home and had no charger that I could set to less than 14.0v. I...

Here is the spec sheet. They clearly say 350A for 2-minutes

I have not. I do not know enough about how the voltage is controlled to figure out how to adjust the regulated output voltage to make it work. I was hoping that someone on this site might have that knowledge.

For me, it was worth the extra cast to get quick delivery from a known vender with a good reputation of delivering quality without hassle.

D'oh! Brain fart, not typo. I went back and fixed it. You don't need to watch it. In fact, watching it will just cause you frustration. You know the old adage. "A watched pot never boils." Until your cells get close to balancing at the 13.6v step, nothing will appear to be happening. It...

Thanks. First off, the alternator is an Ample Power 105A hot rated externally regulated alternator. The Regualtor is a Xantrex InCharge with added controls for limiting the max field current and electronic thermostatic control based on the alternator case temperature. For alternator...

It has a 12v output, but it is only about 8A so not useful in recharging a 560Ah battery.

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...

Which terminals are you referring to? Original 6mm tapped hole, 6mm stud, 8mm stud or the newest offering the 6mm welded threaded screw-in terminal stud? I think that I still like the original best because it has by far the most contact area. If you are careful with the grub screw and support...

I would have tried backing the charge voltage off to the point where it was a high as possible without tripping the OVP and let it go for a day or two. The JK would have brought it into line. my cells hit close to 300 mv delta with cell #3 very low cell and the other three close. It sat for...

My thoughts exactly. Some folks want to be blissfully ignorant about what is happening and just want to plug and play. Me, I have a burning need to know.

It is a semantics thing. Connenting cells in parallel and charging them slowly until they are all at 3.65v is not top balance. It is one of the many methods to top balance. Top balance is a state of being where all of the cells reach the exact same voltage at or near the high limit of 3.60...

The cells that I recieved from the Houston warehouse on 6/9/22 had QR code manufacture dates that ranged from 12/21/21 to 123/29/21.

90% SOC is pretty low for OVP and is hard to control because that is in the flat part of the curve. On my packs, I set OVP to 3.60v but set the charge controllers to 13.8v which is 3.45v. I use a 0.01C tail current for absorb which is 5.6A and it only lasts a few minutes because my cells are...

Second set of corner fixtures off the printer. I should note that these corner fixtures are not intended for compression but to fix the cells in place to prevent movement in any direction. The nyloc nuts will be snugged up just enough to remove any gaps between the parts.

You can use any heating pad you want as long as you use a relay to control the heating pad. I think they are limiting the 100W but I could not find that in the documentation. If you use a relay you can go higher than that.

If you bought it new you should be fine. The problem was only with the units sold in the first few months. I bought mine a week after Nami emailed me to tell me that they were available because I was on the wait list. As they say, good things come to those who wait!

That looks about right. If you are still hitting OVP, then drop the bulk and float to 54v. Once the pack gets balanced, I would suggest dropping the float to 53v and the bulk to 55v. I am not sure what the "Out-Timer" is. Is that the absorption time in minutes. If so, 24 minutes is about...

Your first thought was what I was hoping would be possible. I do not yet have an inverter other than my little 400W modified sine wave and was hoping that i could connect the 120v AC heater directly to 12v but it doesn't look like that will work. I am trying to find something I have on hand to...

The two 460Ah batteries that I got were from Basen Green and cost $1200 with all fees and shipping, delievered to my house. When I receieved them one produced 480Ah on the capacity test (20Ah more than advertised capacity) in spite of the 80mv imbalance. The other only produced 445Ah on the...

Unless I am missing something in your meaning, if you are one cell running at 3.65v with the pack at 55.5V (3.47v average) by definition, they cannot be top balanced.

That is exactly the reason that they calculate the resistance and show that value on the app. @RCinFLA goes into great detail on the system in the link in post #263 above. From everything I have seen, it is a bad idea to have different length of sense wires in any BMS except for the JK BMS...

I used a couple of #2-gauge wires with 1/4" ring terminals crimped with a hydraulic crimper. I could have gone larger because you can get 2/0 in 1/4" ring terminals. I chose 2 Guage because two #2 have the exact same cross section as a single 2/0 which is what the rest of my system is built...

With the JK, I can watch the 2A of balancing. This was with a JK BMS which has active balancing, and the app shows it pulling 2A out of the highest cell and then pushes that same 2a current into the lowest cell. I guess that with that see/saw action it might be that the balancing averages out...

All correct except that the alternator has a mechanical limit as to the max power it can generate. It is not capable of producing more than 190A at 12.0v so that limits the max current to 158A at 14.4v which is well withing the ampacity of the 2/0 wire. Then we need to add to that limit that...

Never been to their site before but they do not seem to have what I need.

If you do not want the parasitic drain, can you just unplug the display after it is started?

I am completely happy with my installation. I have 560Ah with a JK BMS in a 2p4s configuration.

Question for those who have gotten JK BMS's from Hankzor. Were they delivered on time or close to it? I have one that tracking tells me should be delivered on 6/18 and that will give me about 3 weeks to get my battery built and installed which should be ok as long as the BMS is on time or not...

Food for thought The setup. The torture test.

Thanks. the "humped side is on the label side so that same as shown in your photo. Am I correct that the connectors must be attached to the hump side? I am thinking that many of my challenges might be solved by rotating the BMS 90º like you have done or maybe -90º so that the plugs are on the...

She seems to be radio-silent. This silence is very frustrating given that I still believe that the JK is the best thing going but if the seller is not standing up for the odd failure it becomes an expensive crap shoot.

Thanks for the reply. I live in a 12-volt world. Everything on my boat is 12v and my plan is to use EVE 280K in either (8) cells in 2p4s with one BMS or two 4s batteries each with its own BMS for my boat. It will be connected to an EVO 1212 based on researching them after your nice reviews...

Stainless steel has significantly more resistance than does the aluminum terminal or nickel covered copper buss bar so based on Ohms Law the stainless will carry very little current. If you doubt this, put a stainless-steel washer between the terminal and the buss bar and check the heat buildup.

Thanks for the info on the MeanWell chargers. I have not heard of them before. I am looking for a supplemental high-amp charger to add to the 100A output of my Magnum for when I am dry camping. I recharge primarily with my 10kw genset so 100A is a lot of runtime. My BMS's will each handle...

I didn't think about it until I had already left so hopefully all is well. I have seen that they only draw 500mW when running without any outside draws so even if I had left it running it should be fine.

For those of us in higher Latitudes, a heating function would be helpful. It would need an output signal that could be used to trigger a relay to turn on a heating pad on the batteries at a user selectable temperature.

Does the routing of the sense wires on my drawing in post #6 do what you describe? At this time, I do not have a large invertor but am planning to add the Samlex EVO 1212f HW and I had seen the note in their installation manual about taping the + & - together. I am not sure if the EVO is high...

If it all works out nice no problem. If it does not, $$$. You money, your choice. Do you feel lucky?

Your assesement is correct. By setting the absorption voltage to 55v the charge controller will reduce the current to a level that will keep the total pack voltage at 55v. At that point, the voltage of cell #1 will be a bit lower than shown and will not shut down the charging due to OVP. Do...

Thanks Steve. A. There were no loads on at the time of shutdown. The battery selector switch was in the off position and the app showed 0.0A. B. Same condition when I attempted to restart. C. No precharge resistor but do not have a built-in invertor. The power is primarily used as 12v for...

Have you gotten hold of one of the failed 4s JK's to see what is the failing component?

Looking forward to your final analysis and suggestions for repair. My brother-in-law has the necessary skill and tools to make the repair but need to know what to go after. Thanks for the investigation.

Thanks. That looks like 105C EPDB and not silicone but would be a good alternate choice.

I also could have gotten them for $110 from the same company (Docan Power) but that is a shipment from China by boat and the expected delivery time is 2-3 months minimum. These are from their Houston warehouse with 2-3 day shipping to anywhere in the US included in the price. If there are...

The Idea about using old power supplies was something that I read on a forum (so it has got to be true, right?) ;) I did not understand what the system was or even if it would work but thought I would see if anyone here had any insight.

He did is slowly so that he could monitor and make adjustments rather than an all or nothing. The point was that even at the extreme 0%/100% the current was not off the charts. Yes, it did exceed the 200A limit on his meter but not by much. This is evident by the fact that after a few seconds...

I had thought about doing the same and am sure that it will do the same balancing that I have done but I am just paranoid about requiring the BMS to shut down charging. I like it there but do not want to rely on it being there. Like a safety pressure relief valve that you never want to trip.

Has anyone used the EVO data logging feature? If so, what did you record and how do you read the data?

It is listed for both versions of the 4s and Nami said in one of her responses that it applies to all JK BMS's

I have a replacement BMS on the way that should be here next week. This is the BMS that had its case mangled in shipping and I have been concerned about internal issues so had ordered a new one so that I could retire this one as a spare. Up till now it was performed without issue but do not...

You need to remember that the JK is rated to take a surge current of 350A for up to 300-seconds and millisecond bursts at currents than that. This will give a properly sized fast acting fuse sufficient time to bread the connection so that the FETs do not need to. In Andy's first video on the...

I found a manual that Nami uploaded to the documents which has the Chinese instructions and an English translation after it but have not had the time to fully read it. You can probably find some of your answers there. Where did you find the CR code and were the instruction for it in English?

I have never ordered from AliExpress and tried to place an order today. It said that the transaction failed, and I could file an appeal application which seems weird. The appeal wants photographs of my driver's license, credit card and back statement. WTF!!! That just has "scam" written...

This build is for a sailboat on saltwater so I primarily use tinned type 3 fine stranded conductors with a 105C rating. As my wife likes to say "I live on an island in a city with 'Harbor' in its name" so my local Ace hardward stocks many sizes and colors of Ancor marine wire. If they do not...

That is my intent and is why I ordered a second unit. Even though the first failed one will not be used, I want to get it replaced or repaired under warantee.