Chargery BMS, DCC (Solid State Contactor) thread.

[Made in North Pole]

Oh wait... you are the guy I shipped my units to!!! Hyvaa huomenta

True. Only one worked and that one is also history.

 

[Made in North Pole]

onder
I wonder what you used them for. ??? ... I had the smaller 100 amp ones fail w about 3 weeks of use on one of my 80vdc-30Amp PV Inputs to my LV2424 All in One as an OFF switch for BMS Charge Trigger). ... I theorized the MPP protocols going through one of those DCCs does something/ and not a good match mix, ... but no real proof that was the isse. I am using the Kilovac 500 amp relays for my battery off/on switches. ... last couple of new purchases on alxiexpress were < $40 vs sometimes $200 in USA. Ali shipping time was a ok zone too (< 2 weeks).

I used it between PV and Morningstar charge controller. Highest current input was <40A for a 300A DCC, yet it failed. I have been lucky to have the charge controller come to my rescue to avoid overcharge. That thing is dangerous .

 

[Ai4px]

True. Only one worked and that one is also history.

yes, that "one" was new in the box.... damn... the new one failed too? that's terrible. The charger BMS is also badly designed. It measures the bottom of the shunt as ground which means that under high current, all the cells get offsets in their voltage. There is no averaging of cells... at 150amps the 16 cell voltages dance around like crazy... some of them dipping to 2.7v and making the BMS shut off power. But as current approaches zero amps they read much more steady.
I like my JK BMS very well thank you. I spent ... err wasted a lot of money on chargery equipment.

 

[Made in North Pole]

yes, that "one" was new in the box.... damn... the new one failed too? that's terrible. The charger BMS is also badly designed. It measures the bottom of the shunt as ground which means that under high current, all the cells get offsets in their voltage. There is no averaging of cells... at 150amps the 16 cell voltages dance around like crazy... some of them dipping to 2.7v and making the BMS shut off power. But as current approaches zero amps they read much more steady.
I like my JK BMS very well thank you. I spent ... err wasted a lot of money on chargery equipment.

Yes, it lasted for about a month and failed. I never trusted their BMS from the start, I went for Electrodacus SBMS0. Thank you for your kindness by the way.

 

[OffGridICF]

I used it between PV and Morningstar charge controller. Highest current input was <40A for a 300A DCC, yet it failed. I have been lucky to have the charge controller come to my rescue to avoid overcharge. That thing is dangerous .

Just curious, what is the maximum open-circuit voltage from your panels? The drain-source breakdown voltage on the FETs in the DCC-300 is only 60V. There are two in series, but I suspect more than 60V could still cause problems depending on internal timing.

 

[Made in North Pole]

Just curious, what is the maximum open-circuit voltage from your panels? The drain-source breakdown voltage on the FETs in the DCC-300 is only 60V. There are two in series, but I suspect more than 60V could still cause problems depending on internal timing.

PV array is 76V Voc.

 

[mkaye]

yes, that "one" was new in the box.... damn... the new one failed too? that's terrible. The charger BMS is also badly designed. It measures the bottom of the shunt as ground which means that under high current, all the cells get offsets in their voltage. There is no averaging of cells... at 150amps the 16 cell voltages dance around like crazy... some of them dipping to 2.7v and making the BMS shut off power. But as current approaches zero amps they read much more steady.
I like my JK BMS very well thank you. I spent ... err wasted a lot of money on chargery equipment.

i have the 8T (4S) using power plug, not the sense leads for power
my inverter will draw 150A and i don't see any dancing voltages - all within 30mV
i clean the terminals and use NOALOX to keep the contact resistance as low as possible

just re-read your post
the BMS should be powered from the battery posts, not the other side of the shunt

 

[OffGridICF]

PV array is 76V Voc.

Thanks for the info. It seems like there is a good chance that is why they are failing closed. The 60V breakdown voltage is an Absolute Maximum spec in the SFS06R02PF FET datasheet. When you exceed that voltage, the insulating layer in the FET will start to fail creating a current leakage path. Usually when that happens things degrade quickly and it's game over. Normally the DCC is only used to switch batteries less than 60V so the 60V FET rating should be OK.

The Kilovac is a much better choice for switching PV modules.

 

[Made in North Pole]

Thanks for the info. It seems like there is a good chance that is why they are failing closed. The 60V breakdown voltage is an Absolute Maximum spec in the SFS06R02PF FET datasheet. When you exceed that voltage, the insulating layer in the FET will start to fail creating a current leakage path. Usually when that happens things degrade quickly and it's game over. Normally the DCC is only used to switch batteries less than 60V so the 60V FET rating should be OK.

The Kilovac is a much better choice for switching PV modules.

I hope you know that the max voltage rating of the Chargery DCC is 100V. Assuming you are right, should Chargery not provide this information to us?

 

[OffGridICF]

I hope you know that the max voltage rating of the Chargery DCC is 100V. Assuming you are right, should Chargery not provide this information to us?

Oops, good catch. No, I did not check the Chargery DCC voltage specification. I'm sure Chargery has tested the unit to get the 100V rating but they may not have tested it in your configuration.

In an ideal world, the two FETs in series should be OK up to 120V. However, if one of the FETs switches on/off before the other or if one has a lower Rdson than the other, the voltage between the two FETs will divide unequally and one FET could see more than 60V while the other sees less.

I don't have a simple way to check it, but I also wonder if disconnecting the PV panels from the MPPT when it is charging might cause a slightly higher voltage transient. Depending on the wiring, your 40A current might also cause an inductive transient at disconnect. Keeping +/- wires right next to each other for their entire length will minimize their inductance which is especially important with high current circuits.

At this point, I'm afraid I've wandered off into speculation Without being able to measure what happens when the DCC or Kilovac connects and disconnects the PV array it's not possible to know for sure what is happening.

 

[Made in North Pole]

Oops, good catch. No, I did not check the Chargery DCC voltage specification. I'm sure Chargery has tested the unit to get the 100V rating but they may not have tested it in your configuration.

In an ideal world, the two FETs in series should be OK up to 120V. However, if one of the FETs switches on/off before the other or if one has a lower Rdson than the other, the voltage between the two FETs will divide unequally and one FET could see more than 60V while the other sees less.

I don't have a simple way to check it, but I also wonder if disconnecting the PV panels from the MPPT when it is charging might cause a slightly higher voltage transient. Depending on the wiring, your 40A current might also cause an inductive transient at disconnect. Keeping +/- wires right next to each other for their entire length will minimize their inductance which is especially important with high current circuits.

At this point, I'm afraid I've wandered off into speculation Without being able to measure what happens when the DCC or Kilovac connects and disconnects the PV array it's not possible to know for sure what is happening.

You may just be more knowledgeable about the DCC than Chargery as a company. ? Thank you for the insight.

 

[Capt Bill]

I used it between PV and Morningstar charge controller. Highest current input was <40A for a 300A DCC, yet it failed. I have been lucky to have the charge controller come to my rescue to avoid overcharge. That thing is dangerous .

Here is an option for PV to charger controller that I am using for my 80vdc up to 30A max PV Inputs : https://www.amazon.com/gp/product/B07FCKLMNB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1 ... says 80A max for 250ac or 28vdc ... I have two of these working for me last couple of months,... as my PV In relays that my BMSs charge triggers can use to cut off all charging inputs. One relay can handle two channels in, with no problems so far.

 

[Ai4px]

i have the 8T (4S) using power plug, not the sense leads for power
my inverter will draw 150A and i don't see any dancing voltages - all within 30mV
i clean the terminals and use NOALOX to keep the contact resistance as low as possible

just re-read your post
the BMS should be powered from the battery posts, not the other side of the shunt

Oh I tried that too... 30mv? under a load? that's what I'm talking about!!! But my JK BMS works wonderfully.

 

[Made in North Pole]

Here is an option for PV to charger controller that I am using for my 80vdc up to 30A max PV Inputs : https://www.amazon.com/gp/product/B07FCKLMNB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1 ... says 80A max for 250ac or 28vdc ... I have two of these working for me last couple of months,... as my PV In relays that my BMSs charge triggers can use to cut off all charging inputs. One relay can handle two channels in, with no problems so far.

Thank you for your recommendation. I now use Gigavac.

 

[mkaye]

Oh I tried that too... 30mv? under a load? that's what I'm talking about!!! But my JK BMS works wonderfully.

yes, under load, normally <10mV w/o large load
i did get a 5A active balancer and left it on for a couple of days, this really worked
i don't have it connected now as i couldn't find a convenient way to mount it permanently, but it did it's job
the Chargery balancer kicks in @30mV for a bit, but this when the pack gets to 14.2V

 

[Capt Bill]

My Recent Learning from Mistake with two BMS8Ts: ... Do not sticky tape these Chargery BMSs to a wall, or (even worse, as I did) to the inside the styrofoam packing case I used as a holder attachment to my solar wall. Why? The BMS main body needs air flow to dissipate heat when balancing cells, and balance operation turns OFF as BMS case rises to about 30.5 degree C, to protect the BMS. ... When cell balancing is working ... the cell voltage page shows an "l" along side cells being balanced. When temp protection mode happens, those "l" along side balanced cells disappear. *** I now use sticky tape on thin L-brackets (two on bottom/ one on top) to hold my BMS w 1/2" air space to my cement board over plywood solar wall. My Temp Rise during top charge voltages is much slower now/ and stays in the OK zone. ;+)

 

[Nigel Snook]

Does anyone have information on ISO board which is in line with DCC control on separate port, positive bus arrangements?
I have finally had enough of the 300A DCC, at 170A it is dropping more than a volt and getting ferociously hot. I am replacing it with a 500A kilovac. My configuration is a separate port 2P4S 560Ah set up and my question relates to the ISO board that is used when separate port is used on the recommended positive side. I am struggling to find what this ISO board actually does and thus whether I need to use it when I switch to the kilovac.

 

[mkaye]

the DCC needs a much higher voltage to switch the mosfets - the ISO board boosts the voltage so the DCC can work on the + rail
not required for anything but the DCC

 

[mkaye]

My Recent Learning from Mistake with two BMS8Ts: ... Do not sticky tape these Chargery BMSs to a wall, or (even worse, as I did) to the inside the styrofoam packing case I used as a holder attachment to my solar wall. Why? The BMS main body needs air flow to dissipate heat when balancing cells, and balance operation turns OFF as BMS case rises to about 30.5 degree C, to protect the BMS. ... When cell balancing is working ... the cell voltage page shows an "l" along side cells being balanced. When temp protection mode happens, those "l" along side balanced cells disappear. *** I now use sticky tape on thin L-brackets (two on bottom/ one on top) to hold my BMS w 1/2" air space to my cement board over plywood solar wall. My Temp Rise during top charge voltages is much slower now/ and stays in the OK zone. ;+)

yes, i found out the hard way too
i had some foam backing and had a strap to fix it to the back of the cells in my RV
recently it started acting up - i.e. not reading current correctly
bought a used replacement & it works fine
i added just a strip of foam at each end so it can stay cool and mount in the same spot
also changed balancing to charge only

 

[Nigel Snook]

the DCC needs a much higher voltage to switch the mosfets - the ISO board boosts the voltage so the DCC can work on the + rail
not required for anything but the DCC

Great thanks. For interest - do you know what voltage it is boosted to?