Chargery BMS, DCC (Solid State Contactor) thread.

[DerpsyDoodler]

Guinea Pig, yes... spent an obscene amount of cash of relays contactors & even had some made to spec the 500A & 1000A SSRS.
and now I am still using the First Generation of DCC. I have one latest generation DCC en-route to complete my final pack going into my bank, shipped Air Express this morning with other goodies. While you hang on the complainers and those who had issues, yet there are far more folks out there not having any issues and yes they are talking about it on other forums too... IN FACT, that is how I found out about chargery a Couple of years ago, from people using them for recycled EV cells.

The FIRST Generation which is what I posted at the START OF THIS THREAD were updated and changed, lugs are farther apart... Then came the ISO Boards and external adapters which WE here asked for and Jason @ Chargery responded and met the need....

Also to the point, I run DCC-300's and have pulled 250A and pushed 150A through them and they only got warm, not hot and the fans barely came on and that happened when I covered the vent holes (because I wanted to see, what would happen).

BUT a qualifier for that... My Powerhouse is heated to 50F in winter and in summer it never goes above 27C/81F because it is as insulated as my house is with Thermally broken walls with 6" of Foam (5" between studs, 1" between studs & sheathing) and a Cool Roof system for passive venting and a thermal break as well. Not at all typical in most places.

I’m glad you’ve had success with it. I just don’t feel comfortable with it. I feel good about my decision.

 

[curiouscarbon]

revisited OP, terminals seem kinda close still?

do two 4/0 selterm lugs fit on it now with any orientation with more than 10mm of clearance? that’s what i have and would like to connect unmodified.

i could go down to 5mm but it would be very disappointing when copper is a readily available conductor

tesla model 3 uses a solenoid contactor and can pull 1200 ampere

my JBD BMS uses mosfet and places the terminals 80mm+ apart, so can DCC eventually.

i could be ignorant/tired/lacking coffee and missed the right picture

edit: totally believe in the fundamentals and do wish to replace my gigavac contactors with a semiconductor based one eventually. the idle power draw of normal solenoid contactors are really terrible. coil management e.g. gigavac options can get it down to 1-5W but that still doesn’t touch 0.011A

watching this space!

 

[Ai4px]

Maybe im confused. Forgive me but I wanted to at least respond to ya. What happens when the bms disconnects due to battery being drained to low. How do I charge the batteries back up if using common port and it has discharge and charge disconnected. I found another post that was about common/separate port and I asked there if this is off topic for this thread.
If this is talked about somewhere else please direct me to it

I too have considered this. I've elected to accept that a disconnected battery will not reconnect. it will take manual intervention. Here's another issue... let's say I have a battery that disconnects itself. When should it reconnect itself? In my case, I've got three 280ah packs and I worry about a pack joining automatcially if there's a significant difference in voltage between the other packs and the one that just turned itself on. I don't want the current spikes... I don't want some sort of rapid cycling where it connects and 30 seconds later decides 300amps is too much and disconects... only to reconnect again in 30 seconds. I'd rather do it manually and in a contorlled manner.

Just my 2c worth.

 

[curiouscarbon]

i personally plan on requiring manual intervention when one pack disconnects. imbalance reconnect event concerns me too.

eventually a logic gate will activate an isolated dc dc converter, charging the pack until within spec of main bus and auto reconnect.

 

[Ai4px]

BUT a qualifier for that... My Powerhouse is heated to 50F in winter and in summer it never goes above 27C/81F because it is as insulated as my house is with Thermally broken walls with 6" of Foam (5" between studs, 1" between studs & sheathing) and a Cool Roof system for passive venting and a thermal break as well. Not at all typical in most places.

Our house is insulated concrete forms. The house is a Southern Style with a wrap around porch and the basement under that porch is concrete block and a poured concrete slab... so we have an outer and inner basement... the outer basement is under the porch and 8' (2.5m) wide and you can walk around the entire perimeter... good storage space and the inverters and batteries are there as well as the water tank and water heater. The inner basement is, naturally the same size as the upstairs. I have an internet connected power meter and it usually takes about 2-3 days for the hvac to change its rhythm when we get a cold snap. Very well insulated house.

I'm pretty sure there's a bricked up corner nook in there with a couple casks of amontillado.

 

[Cheap 4-life]

I too have considered this. I've elected to accept that a disconnected battery will not reconnect. it will take manual intervention. Here's another issue... let's say I have a battery that disconnects itself. When should it reconnect itself? In my case, I've got three 280ah packs and I worry about a pack joining automatcially if there's a significant difference in voltage between the other packs and the one that just turned itself on. I don't want the current spikes... I don't want some sort of rapid cycling where it connects and 30 seconds later decides 300amps is too much and disconects... only to reconnect again in 30 seconds. I'd rather do it manually and in a contorlled manner.

Just my 2c worth.

So your saying you use 1 relay/common port. That sounds like the way to go for solar systems if the cells are good and you don’t charge or discharge to many amps and make your cells drift often.
Only problem is a chargecontroller being cutoff from disconnecting the battery to it while it was in the process of charging.

 

[Ai4px]

So your saying you use 1 relay/common port. That sounds like the way to go for solar systems if the cells are good and you don’t charge or discharge to many amps and make your cells drift often.
Only problem is a chargecontroller being cutoff from disconnecting the battery to it while it was in the process of charging.

With the chargery, you can absolutely use two relays... one for charing and one for discharging.... gigavac are $95/each. If you use two relays, get the 12v gigavac GV241BAX model with 12v relay contacts, or use the SSR relay I used with GV241FAX model and run the coil off 48v directly from batteries.

 

[wild01]

So your saying you use 1 relay/common port. That sounds like the way to go for solar systems if the cells are good and you don’t charge or discharge to many amps and make your cells drift often.
Only problem is a chargecontroller being cutoff from disconnecting the battery to it while it was in the process of charging.

If you are running an offgrid setup, this is rarely ever an issue, because you will almost always have some ac loads going on your system (lights ac fridge etc) so when the bms unloads the battery it doesn't overload the cc. the cc suddenly has less demand on it, but it isn't completely unloaded, it's still pushing dc power to the inverter (or more accurately the inverter is still pulling power through the cc). In fact it's pretty rare to not have a heavy ac load going during the day after you get used to offgrid life. you run/program heavy loads to run during peak sun as a matter of course. water lawn run ac run heaters do laundry run dishwasher etc.

 

[Cheap 4-life]

If you are running an offgrid setup, this is rarely ever an issue, because you will almost always have some ac loads going on your system (lights ac fridge etc) so when the bms unloads the battery it doesn't overload the cc. the cc suddenly has less demand on it, but it isn't completely unloaded, it's still pushing dc power to the inverter (or more accurately the inverter is still pulling power through the cc). In fact it's pretty rare to not have a heavy ac load going during the day after you get used to offgrid life. you run/program heavy loads to run during peak sun as a matter of course. water lawn run ac run heaters do laundry run dishwasher etc.

Maybe I’ve mistaken. When the bms disconnects “unloads” the battery, the cc is immediately shut completely off. No power can come through the cc when it’s off. I figured The inverter couldn’t pull power through the cc when cc is completely off.

 

[wild01]

Maybe I’ve mistaken. When the bms disconnects “unloads” the battery, the cc is immediately shut completely off. No power can come through the cc when it’s off. I figured The inverter couldn’t pull power through the cc when cc is completely off.

only with a contactor bms. a common port fet based doesn't. it simply stops voltage flow INTO the battery. thus the cc continues to power the inverter as does the battery.

 

[Cheap 4-life]

only with a contactor bms. a common port fet based doesn't. it simply stops voltage flow INTO the battery. thus the cc continues to power the inverter as does the battery.

I’m fairly certain a common port fet bms stops flow out of the battery. From what I’m reading some will allow charge if the bms disconnected battery power due to Lvd. And the other way around.

 

[Steve_S]

A Reminder.... The TOPIC of this thread is ????
Off-topic then please start another thread.

 

[curiouscarbon]

Chargery BMS, DCC (Solid State Contactor) thread.​

 

[wild01]

A Reminder.... The TOPIC of this thread is ????
Off-topic then please start another thread.

Evaluating how a DCC works and whether or not it is the best solution for a system involves discussing how other solutions work. I'm not sure why this is upsetting you so much. How can we discuss the pros and cons of the dcc if we can't talk about any other options???

 

[curiouscarbon]

I wish there were a way to like, categorize posts within a thread and then view the thread chronologically but filtered to only see the tags wanted. This could really alleviate the linear thread constraint when conversation becomes branchy.

Dunno how to implement that here, though..

 

[DerpsyDoodler]

I wish there were a way to like, categorize posts within a thread and then view the thread chronologically but filtered to only see the tags wanted. This could really alleviate the linear thread constraint when conversation becomes branchy.

Dunno how to implement that here, though..

You mean you’d like to be able to tag each post with 1 or several categories? sounds like the way modern email systems (among other things) work. There is also the upvote or “like” system.

As for OT, i feel it necessary to point out that some pointer outers of OT discussion engage in OT discussion before and after their rant about OT in that very same thread. Are we now OT again? ?

 

[curiouscarbon]

On Topic? ? Chargery’s DCC is DireCtly Competing with solenoid type contactors so comparing and contrasting seems good to me?

 

[wild01]

I’m fairly certain a common port fet bms stops flow out of the battery. From what I’m reading some will allow charge if the bms disconnected battery power due to Lvd. And the other way around.

Most common port mosfet based BMS's control charge and discharge flow separately, they can act like one way valves, allowing charge while not allowing discharge, or allowing discharge while stopping charge. (I can confirm that this is how my JBD 8s 100a function as I have watched it/caused it to function this way)

Common port contactor based systems (traditional or dcc ssr)cut off both at the same time.

separate port contactor (traditional or DCC) bms's can cutoff charge and discharge seperately, BUT only if charge and discharge are provided by separate systems. ie stand alone solar cc/ stand alone ac charger/ stand alone inverter. they also cannot allow voltage to go from the charger to the inverter if they isolate the incoming power from the battery.

I was hoping that the DCC had been designed to overcome these shortcomings but alas it has not. I could make a setup using a split/separate port bms and massive blocking diodes to achieve this but I'm afraid it would be terribly inefficient. I know next to nothing about how fet based systems work, but they do work very well in smaller systems.

reasons why I'm disappointed by current offerings. I really like the flexibility that a fet based system allows in every respect but size. I forsee many times when it would be reasonable or neccesary to allow discharge while blocking charge. for one-battery heating in freezing temperatures. I want to set up a heater that gently warms the battery. I also want the bms to protect the battery from this heater overdischarging the battery. Also if a cell overcharges, I want the bms to cutoff charging and allow the system to keep operating and get the battery cell out of an overcharged condition asap. I also want all of the above functionality while still being able to use all in one inverters, or at least inverter chargers...

my hope is by participating in this discussion the next gen of DCC could be designed with these things in mind

 

[Steve_S]

Relays, Contactors, SSR's and more beaten to death here.

SSR testing

Hopefully tonight I will be able to test my SSR's I have 250 Amp and 500 Amp ones. Obviously the first test is weather or not they work. I was also going to run them under load and check temperature often to see how they heat up with and without a heat sink. Does anybody have any other tests...

diysolarforum.com

 

[BiduleOhm]

I could make a setup using a split/separate port bms and massive blocking diodes to achieve this but I'm afraid it would be terribly inefficient. I know next to nothing about how fet based systems work, but they do work very well in smaller systems.

They actually use exactly that: diodes. They aren't additional ones but the mosfets body diode (more info here).

Since they will dissipate a lot more power than with the mosfets closed, you actually can't pass the BMS rated current if it is in charge or discharge mode only so be careful about that.