JK 4S 200A BMS

[rhino]

Any ideas why this one cell (blue) does not appear to be getting balanced? I see the one purple one did properly get balanced. I changed the balance threshold to 3.1V to make sure everything was in range to enable balancing.

 

[Samcat]

My bluetooth is stuck on on the BMS and now I can't connect to it. Probably because I was trying to get the iOS app to disconnect from it but couldn't so I turned bluetooth off on the phone and now BMS still thinks it is connected to phone but phone can't connect to it now. Is there simply way to reset the bluetooth? I didn't want to pull the balance cables since I assume that would cut power to my inverter.

Have inverter on idle use jumper cables while you rebooting BMS. Just my advice.

 

[hwse]

Can anyone tell me how long the 7ga leads are that Hankzor is providing for connection to the B- and P-? I plan to mount the Jk to the end cap of my build and hope that they will reach form both - terminals to the BMS.

 

[rhino]

Can anyone tell me how long the 7ga leads are that Hankzor is providing for connection to the B- and P-? I plan to mount the Jk to the end cap of my build and hope that they will reach form both - terminals to the BMS.

See this post:

Hankzor JK BMS with screen and power button

That's what I use - 16mm² lugs. I agree, it is an odd choice. @Nami :) Maybe we will consider improving this problem. At present, all BMS cable specifications are 7awg, but customers can replace the cable by themselves. For 7awg cable, we can pass the current of 200A in the laboratory

diysolarforum.com

 

[hwse]

See this post:

Do you know how long the 7ga wires are? I will not have any high demands so am happy with the 7ga size and the suppleness is nice. my biggest load is a 500W invertor so nothing major.
In the post supplied, I see 10cm but that is not the 4s. Do they all have the same length? If it is that short, I will probably need to make a couple of new leads because it does not make sense to have bolted on leads with a splice when I only need maybe 8" total.

 

[rhino]

Do you know how long the 7ga wires are? I will not have any high demands so am happy with the 7ga size and the suppleness is nice. my biggest load is a 500W invertor so nothing major.
In the post supplied, I see 10cm but that is not the 4s. Do they all have the same length? If it is that short, I will probably need to make a couple of new leads because it does not make sense to have bolted on leads with a splice when I only need maybe 8" total.

If you are referring to the new 4S version they have threaded holes where you supply your own cable and lugs which I think is better.

 

[rickst29]

Do you know how long the 7ga wires are? I will not have any high demands so am happy with the 7ga size and the suppleness is nice. my biggest load is a 500W invertor so nothing major.
In the post supplied, I see 10cm but that is not the 4s. Do they all have the same length? If it is that short, I will probably need to make a couple of new leads because it does not make sense to have bolted on leads with a splice when I only need maybe 8" total.

Thy're quite short, maybe around 5" long. But they're definitely longer than 10 cm each). If you need more length (B-, or P-, or both sets) you can make bigger terminal wires with more copper, at the length of you need. On my own 230Ah 4s battery pack, I will upgrade both sides to at least dual AWG-2, and perhaps a bit bigger than that. Tinned lugs for all connections.

 

[hwse]

My current battery cables are 2-O which is incredibly oversized given that they only significant current is from the 105 Amp alternator with a 10' run at most. They are too stiff to make the turns that will be needed to get from A to B.
On this build, I will eventually have a 1200W invertor as the max load.

 

[rhino]

My current battery cables are 2-O which is incredibly oversized given that they only significant current is from the 105 Amp alternator with a 10' run at most. They are too stiff to make the turns that will be needed to get from A to B.
On this build, I will eventually have a 1200W invertor as the max load.

My 2/0 has ~1300 strands which just barely allowed me to make a looping turn from the T fuse mounted on side of battery case to the positive on the battery.

 

[hwse]

My 2/0 has ~1300 strands which just barely allowed me to make a looping turn from the T fuse mounted on side of battery case to the positive on the battery.

Wow! How long did it take to count them?!?!?

Given that I have two cell terminals and two BMS lug connections, I plan to use two conductors from the cells to BMS to the ground shunt. All of my conductors between the house bank and the alternator are 2-O. If I want two conductors that equal the cross-section area of a 2-O I will need to use two #2 AWG if my math is correct.
Am I looking at this correctly?

 

[Samcat]

Wow! How long did it take to count them?!?!?

Given that I have two cell terminals and two BMS lug connections, I plan to use two conductors from the cells to BMS to the ground shunt. All of my conductors between the house bank and the alternator are 2-O. If I want two conductors that equal the cross-section area of a 2-O I will need to use two #2 AWG if my math is correct.
Am I looking at this correctly?

Running straight from Alternator to the lifepo4 chemistry is going to overheat and lower your Alternator life quickly. I would advise on some sort of DC-DC converter that can regulate current. Running 100 A for extended periods will heat stator over 70°C even if running high speed on the rotor. Disregard my post if I have misunderstood your comment.

 

[Steve_S]

Can anyone tell me how long the 7ga leads are that Hankzor is providing for connection to the B- and P-? I plan to mount the Jk to the end cap of my build and hope that they will reach form both - terminals to the BMS.

The 7 gauge B- & P- are 4"/10cm long.

My current battery cables are 2-O

My 2/0 has ~1300 strands

Wire Sizes MAY be the same but the Strand Counts VARY a lot based on TYPE/CLASS of Cable. Typical "Auto Cable" is stranded but uses thicker strands providing less "skin" and making them a bit stiffer, while Premium Welding or even Marine Cables use very fine wire strands providing more "skin" while also making them much more flexible. The Fine Welding Cables are also capable of carrying far more current than thick stranded stuff.

BELOW: Two grades from the same Company "SouthWire" Welding Cable. Link to each below the respective images.

Royal® SUPER EXCELENE ® WELDING CABLE UL. Silicone Free​

UL Listed 600 Volt -50°C to 90°C Oil Resistant Premium Grade Orange CPE Jacket.​

LINK: http://industrial.southwire.com/en/tile/10/spec/70300/?country=US

Royal® EXCELENE ® NON-UL WELDING CABLE. Silicone Free​

600 Volt 105°C Flexible Cord. Heat, Abrasion, Tear Resistant, Moisture and Flexible EPDM Jacket.​

LINK: http://industrial.southwire.com/en/tile/10/spec/70305/?country=US

 

[hwse]

Running straight from Alternator to the lifepo4 chemistry is going to overheat and lower your Alternator life quickly. I would advise on some sort of DC-DC converter that can regulate current. Running 100 A for extended periods will heat stator over 70°C even if running high speed on the rotor. Disregard my post if I have misunderstood your comment.

You did not misunderstand my comment, I just did not include all of the info.
My alternator is an external regulated alternator and has a rated maximum safe operating temperature of 100ºC.
I am building a regulator that will have a PWM controller on the field strength that allows me to derate the output to safe levels. It also has thermostatic control that reads the temperature of the alternator's output stud. I will use this to monitor the temperature and then set the PWM to maintain a conservative safe level of somewhere around 80ºC. The thermostat will then be set to have a max allowable temperature of 90ºC. If the alternator hits 90ºC, it will cut the field current until the temperature drops back down to 80ºC.

 

[hwse]

The 7 gauge B- & P- are 4"/10cm long.


Wire Sizes MAY be the same but the Strand Counts VARY a lot based on TYPE/CLASS of Cable. Typical "Auto Cable" is stranded but uses thicker strands providing less "skin" and making them a bit stiffer, while Premium Welding or even Marine Cables use very fine wire strands providing more "skin" while also making them much more flexible. The Fine Welding Cables are also capable of carrying far more current than thick stranded stuff.

BELOW: Two grades from the same Company "SouthWire" Welding Cable. Link to each below the respective images.

Royal® SUPER EXCELENE ® WELDING CABLE UL. Silicone Free​

UL Listed 600 Volt -50°C to 90°C Oil Resistant Premium Grade Orange CPE Jacket.​

View attachment 97304
LINK: http://industrial.southwire.com/en/tile/10/spec/70300/?country=US

Royal® EXCELENE ® NON-UL WELDING CABLE. Silicone Free​

600 Volt 105°C Flexible Cord. Heat, Abrasion, Tear Resistant, Moisture and Flexible EPDM Jacket.​

View attachment 97303
LINK: http://industrial.southwire.com/en/tile/10/spec/70305/?country=US

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 have what I need, I can order pretty much anything and get it in a couple of days.
I looked up the Ancor charges and the circle mill area of two #2 AWG (2 x 66,500 = 133,00) is exactly the same as a 2/O and that should make for more limber wires. I have not found good domestic US sources for large silicone wire that would allow me to go with a bit smaller gage.

 

[hwse]

The 7 gauge B- & P- are 4"/10cm long.

FWIW. I plan to add a Samlex EVO 1212F-HW to the boat thanks to you. I had never heard of them until I was reading one of your posts. The Samlex is almost unheard of in the boating community and I am not sure why. When I first started talking about using one, I got flamed for it with many statements to the effect of "If you use that CFC (cheap foreign crap) you will go up in flames and die" .

After letting that go for a while, I responded with fact that they based in BC, Canada are ABYC A-31 and E-11 compliant. I also noted that there is no place on any Victron documentation or website that makes the same claim about any of the Victron products. Interesting.

I can find no other charger that allows you to set a charge profile absorption that is based on current rather than time. I plan to use 3 stage type 2 during the boating season and the 2 stage type 3 during my off season.

Thanks for the tip.

 

[rhino]

I have not found good domestic US sources for large silicone wire that would allow me to go with a bit smaller gage.

https://www.digikey.com/en/products/detail/sab-north-america/1133502/16254336

Looks like $19/ft for 2AWG?

 

[rhino]

Royal® SUPER EXCELENE ® WELDING CABLE UL. Silicone Free

I couldn't find this in stock anywhere in the USA and had to get a 1300 strand 2/0 cable. There seems to be severe shortage of it?

 

[Steve_S]

FWIW. I plan to add a Samlex EVO 1212F-HW to the boat thanks to you. I had never heard of them until I was reading one of your posts. The Samlex is almost unheard of in the boating community and I am not sure why. When I first started talking about using one, I got flamed for it with many statements to the effect of "If you use that CFC (cheap foreign crap) you will go up in flames and die" .

After letting that go for a while, I responded with fact that they based in BC, Canada are ABYC A-31 and E-11 compliant. I also noted that there is no place on any Victron documentation or website that makes the same claim about any of the Victron products. Interesting.

I can find no other charger that allows you to set a charge profile absorption that is based on current rather than time. I plan to use 3 stage type 2 during the boating season and the 2 stage type 3 during my off season.

Thanks for the tip.

Many LEAP to the ASSUMPTION that they are a Chinese Company and THEY ARE NOT. ASSumptions expose ASSES ! Most especially when they Leap to Conclusions based on those ASSumptions.

SAMLEX has been used in Commercial, Emergency Services Applications (Fire/Ambulance & Even Military) and they've been at it for a long time. They do not "pop out" with new product every 2 weeks like some and everything is tested & rated to the highest level BEFORE they even think of making it available. BUt let the FUD roll on, right.... For them it usually takes at least 2 years to release a product from "alpha Level" but things got buggered up a bit thanks to Covidus Interruptus but that is being sorted but will still take a while.

BTW: Samlex EU carries some different product which is targeted at the EU Market and they cover more Marine Applications as a result.

One thing that affects the Perception and confuses many, Nothing Samlex is "Cheap" and you likely saw that when Inverter Shopping and we all know the saying, "You Get What You Pay For". ie 9Watts in idle no-draw (not powersave mode) hahaha...

 

[rickst29]

I've got some fine-stranded 2/0 "lying around", but the bend radius is large too large to mount the BMS directly on an end of the pack, and the lugs which I have are too wide and long for mounting on the BMS. The hole size is also 8mm, and I need to have 6mm lugs for this job.

I bought a couple feet of AWG-2 welding cable, and some 6mm lugs, for replacement of the 4 JK-supplied 7-AWG silicon wire segments. The JK segments did fine in testing @ 196A continuous over multiple minutes, but dual AWG-2 pairs (equally short) should be slightly more efficient.

Maybe I'm a bit OCD about this topic - but it seems that I'm not alone.

 

[Rednecktek]

So for the BMS's that have holes in the PCB for the wires, brass bolts? Or is there a better non-soldering way?

 

[hwse]

One thing that affects the Perception and confuses many, Nothing Samlex is "Cheap" and you likely saw that when Inverter Shopping and we all know the saying, "You Get What You Pay For". ie 9Watts in idle no-draw (not powersave mode) hahaha...

I was only looking at Magnum and Victron before given their general acceptance as "Marine quality" so in that market place the Samlex products are a good value and provide features not found in the other two.

 

[rickst29]

So for the BMS's that have holes in the PCB for the wires, brass bolts? Or is there a better non-soldering way?

They have flat surfaces, for attaching the lugs of connection cables. Here is a photo of mine, with one wire removed. The JK-provided silicon cables have 8mm lug holes, but the screws are 6mm. (Pay no attention to the irrelevant yellow wire, it is not part of the BMS.) The lug length is a bit limited, but you can grin or cut the excess length from your lugs (if you 'upgrade' to bigger B- and P- cables).

 

[hwse]

They have flat surfaces, for attaching the lugs of connection cables. Here is a photo of mine, with one wire removed. The JK-provided silicon cables have 8mm lug holes, but the screws are 6mm. (Pay no attention to the irrelevant yellow wire, it is not part of the BMS.) The lug length is a bit limited, but you can grin or cut the excess length from your lugs (if you 'upgrade' to bigger B- and P- cables).
View attachment 97321

There does not appear to be much thread length in those holes. What is the recommended torque for mounting the lugs?
For that matter, does anyone know how much torque should be used on the cells with welded on studs?

 

[rickst29]

There does not appear to be much thread length in those holes. What is the recommended torque for mounting the lugs?
For that matter, does anyone know how much torque should be used on the cells with welded on studs?

The threaded insert is steel and welded into the assembly. As a 'tester', I tightened and loosened these bolts multiple times. My ending test was up to 80 inch pounds (9 Nm) on each bolt. That's considerably tighter than the torque I put into the battery pack terminals, and did require a torque wrench. The "limiting factor" in the provided package might be the use of #3 Phillips bolt heads.

The BMS inserts have only about 2 turns of threads, but that was enough for assembly and disassembly multiple times, with no damage to the Threads in the BMS contacts or the provided bolts. If you use a large hillips #3 screwdriver without a torque wrench, you can probably tighten the bolts up to the limit of your hand's ability to hold the screwdriver's grip, while also pressing the bolt downwards to prevent "slippage" of the bit in the Phillips #3 bolts heads.

I don't like using phillps head bolts or screws for anything, but they possibly provided an appropriate "limiter" in this application.

 

[hwse]

The threaded insert is steel and welded into the assembly. As a 'tester', I tightened and loosened these bolts multiple times. My ending test was up to 80 inch pounds (9 Nm) on each bolt. That's considerably tighter than the torque I put into the battery pack terminals, and did require a torque wrench. The "limiting factor" in the provided package might be the use of #3 Phillips bolt heads.

The BMS inserts have only about 2 turns of threads, but that was enough for assembly and disassembly multiple times, with no damage to the Threads in the BMS contacts or the provided bolts. If you use a large hillips #3 screwdriver without a torque wrench, you can probably tighten the bolts up to the limit of your hand's ability to hold the screwdriver's grip, while also pressing the bolt downwards to prevent "slippage" of the bit in the Phillips #3 bolts heads.

I don't like using phillps head bolts or screws for anything, but they possibly provided an appropriate "limiter" in this application.

I was planning to replace the #3 Phillips with a torx head screw and will use my torque wrench to tighten it. I will probably go with something between 7 or 8 Nm. I have seen 4 Nm for the grub screws in the old 6mm tapped terminals but have not seen the recommendation for the welded on studs. Anyone know what is the suggested torque for them?