JBD / Overkill BMS 120A 4S Lifepo4 in series / parallel

Mark44

Retired Traveler with a yen for solar and LIFEPO4
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This is the exact BMS I am using, except that I ordered it from China direct. Time will tell if the Bluetooth app is everything they say. (English for example!). However, I see that the wiring diagram shows only two sets of main wires, and for the intelligencia on the list I have a question. Most other BMS systems have three sets of wires B- C- P-. This has only 2, B- and C-. What gives?
 

sparklehunt

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To the original question postulated in the thread.

Does anybody have a close-up picture of the mosfet used in the overkill solar/jiabaida/xiaoxang BMS? A quick look at the datasheet can give insight into whether it can handle being in series to a higher voltage.

As to parallel, as long as each bms is programmed the same with the same length wires, I think of no reason to fail.
 

curiouscarbon

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To the original question postulated in the thread.

Does anybody have a close-up picture of the mosfet used in the overkill solar/jiabaida/xiaoxang BMS? A quick look at the datasheet can give insight into whether it can handle being in series to a higher voltage.

As to parallel, as long as each bms is programmed the same with the same length wires, I think of no reason to fail.
1630637251615.jpeg1630637309861.jpeg

mosfet on backside:
1630637336017.jpeg

mosfet on frontside:
1630637483608.jpeg
 

curiouscarbon

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by the way, i just thought to mention,

on the 4S 120S JBD BMS,
the thermal pad on the front side is 1.6mm thick.
the thermal pad on the back side is 0.8mm thick.

if you damage either while disassembling, these are the thicknesses of thermal pad you’ll need.

i measured them with a digital caliper.

FYI.
 

curiouscarbon

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Does anybody have a close-up picture of the mosfet used in the overkill solar/jiabaida/xiaoxang BMS? A quick look at the datasheet can give insight into whether it can handle being in series to a higher voltage.

perhaps it is a Huayi Microelectronics MOSFET inside my specific 4S JBD OverkillSolar 12V BMS....

1630646017578.png1630646097075.png


Original HYG013N04NA1B6 N channel 40V 354A field effect MOS tube package TO-263-6

Potentially a 40V part.

This (Super Spammy Looking) link is the best I could find... https://www.yoycart.com/Product/626710881473/

Can't find datasheet. Only could find datasheet for HY G023N03 Not HY G013N04.

This suggests it's ok to use for 24V series use but NOT 48V.
 

sparklehunt

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Wow thanks!
by the way, i just thought to mention,

on the 4S 120S JBD BMS,
the thermal pad on the front side is 1.6mm thick.
the thermal pad on the back side is 0.8mm thick.

if you damage either while disassembling, these are the thicknesses of thermal pad you’ll need.

i measured them with a digital caliper.

FYI.
What is the thermal pad, that gold looking bar across the row of mosfets?

perhaps it is a Huayi Microelectronics MOSFET inside my specific 4S JBD OverkillSolar 12V BMS....

View attachment 62880View attachment 62883


Original HYG013N04NA1B6 N channel 40V 354A field effect MOS tube package TO-263-6

Potentially a 40V part.

This (Super Spammy Looking) link is the best I could find... https://www.yoycart.com/Product/626710881473/

Can't find datasheet. Only could find datasheet for HY G023N03 Not HY G013N04.
Nice detective work! I was looking for like 15minutes but could only find spammy rando websites also.

I can't imagine that these mfgs even have the data to compile into a datasheet. Maybe they just copied the manufacturing process and design from a real semiconductor company and sell it.

Looking at some similar-looking parts of power N MOSFETs from common mfgs.

Infineon has a D2PAK 7pin package that looks very similar. Problem is, this D2Pak-7p package exists in both 12-40v and 45-80v variants. So
This suggests it's ok to use for 24V series use but NOT 48V.
Agreed. Conclusion is it is ok to put 2x of this particular BMS in series for 24V. Also good idea to have battery balancer between the 12V banks.

Edit: oh I wish they just ponied up a couple more cents to put the 60V part in.
 
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curiouscarbon

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What is the thermal pad,
thermal pad not visible in any of the pics since it has been peeled off to reveal MOSFET face.

This is what it looked like before removing the thermal pad, which just facilitates heat to move from the MOSFET to the metal casing of the BMS. It’s just like a silicone sheet in some cases.

1630709133727.jpeg

that gold looking bar across the row of mosfets?
AFAIK that gold looking bar is busbar to facilitate electrical conduction to the B- and C- posts.

FWIW I applied new thermal pad during reassembly and this is what it looked like right before screwing the metal case back on:
1630709327165.jpeg

The pads I used were slightly thicker than the originals (by at least 0.5mm) and the case screwed back on fine and is now nice and taught sprung against the pads.

Hope this helps
 

BobFlyer

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Aug 25, 2021
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Wow thanks!

What is the thermal pad, that gold looking bar across the row of mosfets?


Nice detective work! I was looking for like 15minutes but could only find spammy rando websites also.

I can't imagine that these mfgs even have the data to compile into a datasheet. Maybe they just copied the manufacturing process and design from a real semiconductor company and sell it.

Looking at some similar-looking parts of power N MOSFETs from common mfgs.

Infineon has a D2PAK 7pin package that looks very similar. Problem is, this D2Pak-7p package exists in both 12-40v and 45-80v variants. So

Agreed. Conclusion is it is ok to put 2x of this particular BMS in series for 24V. Also good idea to have battery balancer between the 12V banks.

Edit: oh I wish they just ponied up a couple more cents to put the 60V part in.
I looked at the Overkills pdf on the JBD BMS, and they state on page 30 it is o.k. to use in series. vague on what the max number in series. That is number of individual 12dc xxxah each with own BMS in series. How do you monitor a 24vdc pack? With each 12vdc pack own BMS via Bluetooth?
Is there a setup option to use the bluetooth this way, I.E. monitor each pack with them in series?
I know they make a 8s 24vdc bms, but I wish to have two separate packs each with own bms so I could use just one pack on occasions.
I have the SP04s020A4S with bluetooth dongle...two each for a series setup on hand. I have not yet received my batteries yet, so I cannot test on my own at this point in time they are on a slow boat from China.
Thanks in advance for any feedback
 

Just John

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Wow thanks!

What is the thermal pad, that gold looking bar across the row of mosfets?


Nice detective work! I was looking for like 15minutes but could only find spammy rando websites also.

I can't imagine that these mfgs even have the data to compile into a datasheet. Maybe they just copied the manufacturing process and design from a real semiconductor company and sell it.

Looking at some similar-looking parts of power N MOSFETs from common mfgs.

Infineon has a D2PAK 7pin package that looks very similar. Problem is, this D2Pak-7p package exists in both 12-40v and 45-80v variants. So

Agreed. Conclusion is it is ok to put 2x of this particular BMS in series for 24V. Also good idea to have battery balancer between the 12V banks.

Edit: oh I wish they just ponied up a couple more cents to put the 60V part in.
JBD tells me they use the 80v rated parts. You can run them in series.
 

Just John

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perhaps it is a Huayi Microelectronics MOSFET inside my specific 4S JBD OverkillSolar 12V BMS....

View attachment 62880View attachment 62883


Original HYG013N04NA1B6 N channel 40V 354A field effect MOS tube package TO-263-6

Potentially a 40V part.

This (Super Spammy Looking) link is the best I could find... https://www.yoycart.com/Product/626710881473/

Can't find datasheet. Only could find datasheet for HY G023N03 Not HY G013N04.

This suggests it's ok to use for 24V series use but NOT 48V.
You guys should probably start asking JBD. The last data sheet they sent me even tells you which MOSFETS they use (even an alternate part number). They are very good at answering questions. I admit it is not as much fun, but you get real answers.
 

curiouscarbon

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You guys should probably start asking JBD. The last data sheet they sent me even tells you which MOSFETS they use (even an alternate part number). They are very good at answering questions. I admit it is not as much fun, but you get real answers.
Speaking with the manufacturers, big agree! Totally worth doing!

Very glad to hear that Jiabaida staff are helpful to inquiries about their hardware and willing to equip end user with necessary information for appropriate safety and general engineering requirements.

Thank you for your efforts in communicating with Jiabaida staff. Perhaps I’ll say hello someday with curiosities :)


This is the proper link to the appropriate entity?
 

Just John

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Speaking with the manufacturers, big agree! Totally worth doing!

Very glad to hear that Jiabaida staff are helpful to inquiries about their hardware and willing to equip end user with necessary information for appropriate safety and general engineering requirements.

Thank you for your efforts in communicating with Jiabaida staff. Perhaps I’ll say hello someday with curiosities :)


This is the proper link to the appropriate entity?
Yes, that's the link I use.
 

Just John

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Thank you for confirming! Sometimes there are offshoot stores; I appreciate it.
Yes, they also have an Aliexpress store, and lithium battery is a related website/company. It is common for Chinese companies to have multiple "companies", so I verified some of them. When I get to my PC, they even specify which TI bms chip they use along with the MOSFET parts. Apparently it is a common question. Daly on the other hand keeps it secret, to the point of removing chip labels. They started telling you about series because they apparently get the question frequently.

1633905549273.png
 

Just John

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Just as an FYI, the parts they use for their 200 amp 4s BMS:

5. Main material Serial number Material name Manufacturer Dosage 1 2 3 4 NANO100SD3BN BQ7692003PW HYG013N04NA1B6 orHY4903 PCB-JBD-SP04S034 V1.2 nuvoton TI 1PCS 1PCS 30PCS 1PCS Hua Yiwei JBD Note: The above materials may be replaced by materials with the same specifications or better specifications. If the materials are not allowed to be replaced by certification requirements, we need to notify our business to re-sampling, the controlled specifications, and the final interpretation right belongs to Jiabaida .

Screenshot 2021-10-10 200105.jpg
 

sparklehunt

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That BOM gives me more confidence in their product.

Since JBD's time zone is flipped from ours, can you share the full datasheet you got from them?
Just as an FYI, the parts they use for their 200 amp 4s BMS:

5. Main material Serial number Material name Manufacturer Dosage 1 2 3 4 NANO100SD3BN BQ7692003PW HYG013N04NA1B6 orHY4903 PCB-JBD-SP04S034 V1.2 nuvoton TI 1PCS 1PCS 30PCS 1PCS Hua Yiwei JBD Note: The above materials may be replaced by materials with the same specifications or better specifications. If the materials are not allowed to be replaced by certification requirements, we need to notify our business to re-sampling, the controlled specifications, and the final interpretation right belongs to Jiabaida .

View attachment 68389

However: Googling HY4903 shows only a 30V max Vdss though which contradicts their ad saying it can go up to 80V.

1633988674909.png
 

Just John

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That BOM gives me more confidence in their product.

Since JBD's time zone is flipped from ours, can you share the full datasheet you got from them?


However: Googling HY4903 shows only a 30V max Vdss though which contradicts their ad saying it can go up to 80V.

View attachment 68488
Who knows how many Chinese data sheets it doesn't find. Yes, I will share the datasheet. It is for the new 200 amp BMS, I haven't asked if it is rated for series connection. I am mainly interested in 0.5C or below. I know the 100, 120, and 150 amp BMS are rated.

I am not sure what timezone you think I am in, I am in Phoenix.
 
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RCinFLA

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If you use a BMS in a series battery array that is above its MOSFET switch breakdown voltage you will not know until cutoff is needed. As long as switch stays closed it will not show any problem.

If it has a bms cutoff for some reason the shutoff MOSFET can avalanche (like zener), gets very hot and either blows open or short. Usually its goes shorted meaning the BMS does not cutoff when it should.

Is it worth putting your batteries at risk if BMS does not shut down when it is needed to.

The cost of MOSFET's goes up for low Rds_ON and higher Vds_breakdown. Above 40v breakdown the cost of low Rds_ON resistance MOSFET are much higher so BMS's for 4s and 8s may all use 40v breakdown MOSFET's just so manufacturer does not have to source two different parts.

Really have to be careful of cheap 12v LFP batteries. They are striving to squeeze every penny of manufacturing cost out of them so may use 25-30v breakdown MOSFET's in their internal BMS. If their specs do not specifically state they are stackable assume they are not.

For 16s BMS, 80v breakdown is minimum, 100v breakdown preferred. With long pos and neg separated battery cables there can be voltage ringing.

Battery line series inductance is reduced if you parallel tape together pos and neg cables, which reduces ringing. This also puts less stress on inverter input bypass electrolytic capacitors and inverter switching MOSFET's.
 
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