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Chargery BMS now with Low Temp Cutoff

DW SD said:
Craig, You are a bit ahead of me, but I do have the Chargery BMS setup. It is strange that you have two sets of voltage readings. I looked at mine and the readings are also not consistent. My impression is the one screen is historical, as if an alarm were triggered.

There is a youtube video on setting up a new shunt offset with chargery. Did you review that? I suspect it'd resolve the shunt thing.
Click to expand...
yes i saw this video and i just rewatched the video. His bms is seeing current. my bms is not seeing any current but my trimetric does see current and the current is equal to what my tristar solar controller says. I'm going remove the current wires at the shunt tomorrow to see if the Chargery wiring is not making a good connection and it is wired properly
 
grizzzman said:
Where are you getting the positive sense lead for the TM? Right at the battery positive?
Click to expand...
The tm is getting the reading on the bus bar 12" away from the positive post via a single cable that feeds the bus bar. the shunt is wired correctly weather the wires from the bms to the shunt are making proper connection stacked on top of trimetric's current sense wires is what i'm going to look at tomorrow. the battery pack is taking a charge no problem. that's what the trimetric battery monitor says. matter of fact it looks like the 2 charge and discharge relays use about 1.5 amps.
 
hmmm. strange. maybe that shunt isn't compatible? But I'd have thought they all work about the same.
Did you try measuring voltage on the shunt yourself?

Doug
 
If you are looking for lower consumption relay... check out gigavac GV200 with economizer circuit. It draws 2.8W is about $130. These are used in EV applications (called contactor). Very robust. There are also knockoffs on electric vehicle car parts' website. And EVwest, I think. They might have some used ones.

Note, since I have Magnum inverter / charger all - in -one in my RV and also 12V loads which I can't really separate, I'm using only one relay / contactor.
The charge relay output from Chargery, I'm using to trigger a Bosch cube relay which will interrupt the trigger circuit of the Gigavac contactor. The second relay is very low draw (1.5W). So, load and charge will be interrupted if ANY of the BMS's conditions are met. Still, I don't expect to push charging or load or temp limits.
 
Steve_S said:
maybe you did not notice this one line: MSRP: $240.99
the ML series hover around MSRP $230 ish...
Click to expand...
LOL I did noticed that was kinda my point for how simular they were as references and the price difference
 
The BlueSeas L solenoid looks identical to Gigavac GV200. It might even be white-labeled.

Doug
 
Craigmck said:
yes i saw this video and i just rewatched the video. His bms is seeing current. my bms is not seeing any current but my trimetric does see current and the current is equal to what my tristar solar controller says. I'm going remove the current wires at the shunt tomorrow to see if the Chargery wiring is not making a good connection and it is wired properly
Click to expand...
Well i'm a dumb ass went through the wiring on the bms found i must have unplugged the current sense wires at some time. Reconnected back to the bms and is now working great now.
 
Am I figuring this right? The BMS8T set-up I'm considering has 2, 200A charge relays that have a power consumption of .96A according to the manual, and 2, 400A discharge relays that have a power consumption of 1.24A. Does this mean that in a 24-hour period the relays alone would consume:
2(.96A) + 2(1.24A) x 24 hrs = 105.6Ah/day! :eek: This can't be right!
 
Yes it is...

With a capacitor and resistor you can divide that by 2.

With SSR you can divide that by 20 but they are expensive.

With latching relays you can divide that by 1000+ but they'll need some extra components (at least some capacitors) because the BMS can't control them natively.
 
BiduleOhm said:
Yes it is...

With a capacitor and resistor you can divide that by 2.

With SSR you can divide that by 20 but they are expensive.

With latching relays you can divide that by 1000+ but they'll need some extra components (at least some capacitors) because the BMS can't control them natively.
Click to expand...
Can you provide specific components and a diagram for the economizer circuit for the Chargery relays as well as more details on a latching relay and how to implement the extra components?
 
BiduleOhm said:
Yes it is...
Click to expand...
Thanks BiduleOhm! OK, here's another question that will expose my electrical shortcomings (I haven't even gotten to studying the DC fuse block of the equation yet, so not sure how that all is wired in) but here goes. I will likely use my inverter for no more than 15 minutes per day, so If I put my BMS8T into sleep mode when not using the inverter, will that stop the power consumption of the relays? But if I did put the BMS into sleep mode, would my batteries still power my DC loads through my DC fuse block (of particular concern is powering my DC refrigerator, which would essentially need to be powered throughout the day)?
 
Last edited:
lmwilco1 said:
Can you provide specific components and a diagram for the economizer circuit for the Chargery relays as well as more details on a latching relay and how to implement the extra components?
Click to expand...

Sans titre.png

That's for a 24 V 1 A relay.

For the latching relay it depends of a lot of things (there's multiple latching relays types) and I forgot to mention it would need a manual reset, not really the best thing.

Calothrix said:
I will likely use my inverter for no more than 15 minutes per day, so If I put my BMS8T into sleep mode when not using the inverter, will that stop the power consumption of the relays?
Click to expand...

I didn't look how this BMS works exactly but, presumably, yes.

Calothrix said:
But if I did put the BMS into sleep mode, would my batteries still power my DC loads through my DC fuse block (of particular concern is powering my DC refrigerator, which would essentially need to be powered throughout the day)?
Click to expand...

Yes if the fuse block is connected to the battery directly (not recommended for obvious reasons), no if it is connected through the BMS relay like the inverter.

But why not just shut off the inverter with its power button?
 
I'm confused... will you have 2 BMSs - IE two parallel battery banks? If only one, you would need a maximum of 2 contactor relays.
If your inverter also has charging feature, I'd advocate for a different configuration.

If yours is similar....
Just use 1 contactor relay like the Gigavac GV200M. It only draws .13A. This would be controlled by the load outputs from the Chargery.

Then use a separate Bosch cube type relay to control the trigger (ground) - #85 on the Gigavac GV200. The charge side output from Chargery controls the Bosch relay.
So the ground output from the Chargery for the load relay control is interrupted by the Bosch cube relay. And connected to posts 30 and 87. Post 86 on the Bosch would be positive from the Chargery charge.
I could draw a picture if it'd help.
A side benefit is the Bosch cube relay is also low draw. ~.15A
 
Note, in my proposed configuration, there are potential corner cases where the battery is over-protected. For example, battery temp is below zero, but you are drawing power from the battery. Under temp charge can destroy the battery, but you can safely discharge.

So... ANY condition which triggers either a load or discharge relay to open would open my 1 Gigavac contactor relay.

It is necessary for me, since my inverter is both load and charger.
 
Calothrix said:
OK, here's another question that will expose my electrical shortcomings (I haven't even gotten to studying the DC fuse block of the equation yet, so not sure how that all is wired in) but here goes. I will likely use my inverter for no more than 15 minutes per day, so If I put my BMS8T into sleep mode when not using the inverter, will that stop the power consumption of the relays? But if I did put the BMS into sleep mode, would my batteries still power my DC loads through my DC fuse block (of particular concern is powering my DC refrigerator, which would essentially need to be powered throughout the day)?
Click to expand...
If you put into sleep mode both relays are disconnected. So no.
 
BiduleOhm said:
View attachment 9263

That's for a 24 V 1 A relay.

For the latching relay it depends of a lot of things (there's multiple latching relays types) and I forgot to mention it would need a manual reset, not really the best thing.



I didn't look how this BMS works exactly but, presumably, yes.



Yes if the fuse block is connected to the battery directly (not recommended for obvious reasons), no if it is connected through the BMS relay like the inverter.

But why not just shut off the inverter with its power button?
Click to expand...
Sense the Chargery contactors are "peak and hold" (it has two coils one high amp that over comes the return spring and a smaller low amp coil) The high amp coil is on for a very short time then the low amp coil takes over. The "max" watts are 4-10 (normally takes less then rated) The down side of using a "RC network" econimizer circuit is that it's not recommended if the application is mobile.
 
grizzzman said:
Sense the Chargery contactors are "peak and hold" (it has two coils one high amp that over comes the return spring and a smaller low amp coil) The high amp coil is on for a very short time then the low amp coil takes over. The "max" watts are 4-10 (normally takes less then rated)
Click to expand...

That's exactly what the RC network do. It's just less efficient than 2 separate coils because you loose some power in the resistor but it's better than nothing. But if the relays have this functionality already, why the question was asked in the first place?

grizzzman said:
The down side of using a "RC network" econimizer circuit is that it's not recommended if the application is mobile.
Click to expand...

That is the case if you try to push the economy too far, but with a 1:2 ratio only it's pretty safe, even in mobile applications. The G force it would take to open a closed relay, even at half the coil current, would probably destroy a lot of things in your vehicle, including yourself.

Calothrix said:
If I shut off the inverter but not the BMS, wouldn't there still be power going to the relays?
Click to expand...

Yes. But if there's no power to the relays how your others loads are powered then?
 
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