Will blasts Chargery

[Will Prowse]

@Will Prowse I am still in the market for a 'final' bms solution but the reason I am not using my ANT anymore is that the max charge supported, 50a. I normally charge at twice that amount. It looks like the one you linked to also is limited to 50a. View attachment 12539

Is there a way around that for ANT or Smart BMS options? I have not found any outside of Daly.

Which one do you have? They have different sizes and you can change the charge rate in the settings.

And I wouldn't use HVD on most BMS anyways. Just run charge controller direct and set absorption manually with a coulomb meter. I trust a high quality SCC over a Chinese BMS hvd anyday. Electrolyte degradation doesn't occur till 4.2v per cell for LiFePO4 anyways. HVD really isn't that crucial, especially if top balanced and as mentioned earlier, manually setting absorption

 

[Cal]

Difficult to detect without data logging?? Everything you posted can be deduced pretty easily with a cell monitor with IR measurement, and using an infrared heat gun for a few minutes. If something was wrong, you can easily spot it with a capacity test or feeling the cells with your hand. It really is not that difficult.

With all that said, data logging is fun. And useful for diagnosis of problems. But all of these things mentioned can be found within minutes with basic electrical/temperature probes. But yeah, to each their own. I see why some like it.

One would want do perform verification and validation over the entire spectrum of operation. The charge curve of LiFePO4 cells are somewhat complex, consisting of a lower and upper knee and a reasonable linear response in between. With data logging, all that is presentable in one view. You are talking about STATIC measurements. You are taking measurements at one point in time. Since battery charge and discharge curves are dynamic, you are missing quite a bit of data. I detected several issues with the Chargery settings that you would not have found in minutes if at all.

There are so many possibilities with what you can do with logged data. For instance, at a constant charge current, I can calculate the equivalent capacitance of the battery in a matter of seconds. Capacitance is be equivalent to the AH rating. Now I don't have to totally charge and discharge the battery to check capacity over the years. You might be able to perform all the tests and data gathering manually, but that's extremely time consuming. I just connect the data logger, turn on some loads now and then (or charging sources), and let it run for however long I want. Later all the data is at my finger tips in an Excel file. It couldn't be much simpler. It's not about data logging being fun. It's about getting the total job done in an efficient manner.

 

[solardad]

Which one do you have? They have different sizes and you can change the charge rate in the settings.

And I wouldn't use HVD on most BMS anyways. Just run charge controller direct and set absorption manually with a coulomb meter. I trust a high quality SCC over a Chinese BMS hvd anyday. Electrolyte degradation doesn't occur till 4.2v per cell for LiFePO4 anyways. HVD really isn't that crucial, especially if top balanced and as mentioned earlier, manually setting absorption

@Will Prowse I bought this one last year from ICGOGO https://www.ebay.com/itm/192713045620 200a version.

My ANT BMS is disconnected now so I can not check the settings but mine is similar to the one that you posted and has a stated max charge rate of only 50a. Were you able to confirm you can change the charge rate higher than 50a on yours? If so what model, link?

 

[JoeHam]

For me, it's not a single setting or single special feature, but a combination of features:

• 48V/16S compatibility and hardwired serial comms
• selectable top/bottom/both balancing
• Jason is actively engaged in continuous product development, and listens to customer requests
• The chargery is the best fit for my system, at a great price

For me all of those applied and one more:

I was able to get it in just three days.

I am genetically deficient of patience and the BMS got to me before I did anything stupid with my new cells ?

 

[Will Prowse]

One would want do perform verification and validation over the entire spectrum of operation. The charge curve of LiFePO4 cells are somewhat complex, consisting of a lower and upper knee and a reasonable linear response in between. With data logging, all that is presentable in one view. You are talking about STATIC measurements. You are taking measurements at one point in time. Since battery charge and discharge curves are dynamic, you are missing quite a bit of data. I detected several issues with the Chargery settings that you would not have found in minutes if at all.

There are so many possibilities with what you can do with logged data. For instance, at a constant charge current, I can calculate the equivalent capacitance of the battery in a matter of seconds. Capacitance is be equivalent to the AH rating. Now I don't have to totally charge and discharge the battery to check capacity over the years. You might be able to perform all the tests and data gathering manually, but that's extremely time consuming. I just connect the data logger, turn on some loads now and then (or charging sources), and let it run for however long I want. Later all the data is at my finger tips in an Excel file. It couldn't be much simpler. It's not about data logging being fun. It's about getting the total job done in an efficient manner.

What settings did you change? I still don't get the point. Why do you care about the capacitance? When has that figure changed anything in your design?

Missing data for what? Cycling bandwidth? Even though it's dynamic, it doesn't make a big difference because with LiFePO4, the voltage curve becomes quite dramatic at high and low SOC, so using normal voltage cut offs work fine. What is your goal exactly? Not sure what you are trying to control and what the point is.

And yes, static measurements because these are simple systems. There are no signal control systems or anything that we need to plot data over time. It's just a bunch of voltage sensitive switching and converting. What are you trying to optimize? If it works, then it's fine. Can you give actual examples of optimizing your system with your data logging? Have IR and capacitance really been an issue for you?

If you are running high c rates, then I would understand why you need to log this stuff. But for solar? I just don't see the point. You are trickle charging it. Changing the voltage cut offs for various SOC does not need data logging. Just watch SOC rise to what you wish to cycle to, then log highest cell voltage and set the absorption on SCC.

 

[Will Prowse]

@Will Prowse I bought this one last year from ICGOGO https://www.ebay.com/itm/192713045620 200a version.

My ANT BMS is disconnected now so I can not check the settings but mine is similar to the one that you posted and has a stated max charge rate of only 50a. Were you able to confirm you can change the charge rate higher than 50a on yours? If so what model, link?

Any common port BMS should handle high charge rate. Usually it's separate port that is limited. Hook it up to your pack with just balance lead and change the settings. Should work fine

 

[Bob B]

Why exactly do people prefer the chargery over SBMS or ANT BMS? I can't think of a single setting or special feature to make someone choose the Chargery. Am I missing something? Is it the 1.2A for balancing perhaps?

I just cannot find a reason people would choose the chargery over other options these days. There are even CAN bus communication BMS from Daly. So many options available these days. Really confuses me why folks are trying to make the chargery work when there are easier/cheaper options available.

Standby consumption of most FET based BMS is .2 mA. That is really tiny. Why mess with these relays?

I don't want the inverter load current .... or the charge current... to be going thru to be going thru a relay or a FET. I also want to be controlling charge and load independently. The only thing I want to have in the charge and load circuit is manual shut-offs and fuses. It just seems to me that it is not a good idea to be controlling the high current DC side of things .... Can the Ant do that?

I want to be able to control the devices with a remote signal. I will be doing my inverter like you did in your video with the SSR relay inline with the power switch. I haven't chosen my SCC .... yet, but I will be controlling it and the AC charger in a similar way.

 

[KohalaJim]

I've been looking into the Electrodacus SBMS0 and on page 16 of the user manual it states, "The max charge current can be set between 10A minimum and 600A max for SBMS0 ."

Charge current is a "target setting" for the SBMS and is ultimately dependent on your solar array(s) paired against the ideal charge rate of your pack chemistry. If you employ the use of the "Dual PV" capability of the SBMS0 you can attain this target rate via gating your PV sub-arrays using the EXT-IO options that are available. For LFP, it's been suggested to charge for ultimate longevity from 0.2C-0.3C.

Dacian refers to this as the "panels are cheaper than batteries" argument.

 

[Will Prowse]

One would want do perform verification and validation over the entire spectrum of operation. The charge curve of LiFePO4 cells are somewhat complex, consisting of a lower and upper knee and a reasonable linear response in between. With data logging, all that is presentable in one view. You are talking about STATIC measurements. You are taking measurements at one point in time. Since battery charge and discharge curves are dynamic, you are missing quite a bit of data. I detected several issues with the Chargery settings that you would not have found in minutes if at all.

There are so many possibilities with what you can do with logged data. For instance, at a constant charge current, I can calculate the equivalent capacitance of the battery in a matter of seconds. Capacitance is be equivalent to the AH rating. Now I don't have to totally charge and discharge the battery to check capacity over the years. You might be able to perform all the tests and data gathering manually, but that's extremely time consuming. I just connect the data logger, turn on some loads now and then (or charging sources), and let it run for however long I want. Later all the data is at my finger tips in an Excel file. It couldn't be much simpler. It's not about data logging being fun. It's about getting the total job done in an efficient manner.

How large is your system? Are you using used cells? Mismatched IR cells are usually not a problem for solar because c rate so low. Maybe I am misunderstanding your application. Or are you using used cells on a small pack to power high surge HF inverters? What is your c rate?

 

[Will Prowse]

Anyone see this contactor: https://www.batteryspace.com/relaye-mechcontactor500actrl-v9-36dcvol-rtg12-900dcforbms.aspx

1.7W hold current. Seems like a massive upgrade compared to the chargery relay

 

[FilterGuy]

Then give up using a BMS and go it in the rough without any last ditch safeties... What the heck it's just batteries & money which everyone can chuck out the door easy peasy ! WHY Have a BMS that cannot shut things down if something goes wrong ? Here's an idea, nail all the doors & windows on your house shut to prevent burglars... Or why bother installing Lug Nuts on the wheels of your car, they are only there to attach the wheels & keep them on, no safety reasons at all... Without RELAYS there is no point, it would show you cell voltage and do passive balancing which can be done with a simple battery monitor and no time wasted on BMS anything.

Seriously... some of the stuff posted is just .... oivey !
This has become absurd, seriously absurd.

Wow!... I am not sure what I said to evoke that response. Sorry if I offended in some way.

All I was saying is that relays are not my thing...so using a Chargery with relays is not something I would do. I immediately followed that with a comment that I am considering using the Chargery in situations where I can use the Chargery relay signals to directly control the charge and load devices. I also understand that others don't see the relays as a problem...and I am fine with that. We all have different situations and value sets.

I have nothing against the Chargery BMS. It is one of many options I consider when designing a system for someone. It fits well in some situations and not-so-mutch with others.

Note: The reason I am not a fan of relays is that most of the systems I do are small mobile systems where the relay energy would be a healthy percentage of the total generated power. (In the design I am considering the Chargery for, two relays would probably eat around 10% of the generated power) In addition, IMHO using the signals to directly control the load and charge is a better solution. I also have a fear (perhaps irrational) of SSR failures due to surge currents and voltage spikes.

 

[FilterGuy]

Anyone see this contactor: https://www.batteryspace.com/relaye-mechcontactor500actrl-v9-36dcvol-rtg12-900dcforbms.aspx
View attachment 12563
1.7W hold current. Seems like a massive upgrade compared to the chargery relay

Ouch!!!!

 

[Will Prowse]

View attachment 12564

Ouch!!!!

Oh I know haha! super expensive

This is another reason I avoid relay systems

But people still seem to want charge/discharge relay systems. So thought I should show the options available. I am not a fan of it at all

 

[solardad]

Any common port BMS should handle high charge rate. Usually it's separate port that is limited. Hook it up to your pack with just balance lead and change the settings. Should work fine

Thanks Will for the feedback.

 

[Ampster]

Electrolyte degradation doesn't occur till 4.2v per cell for LiFePO4 anyways.

That is a pretty high voltage to take a LiFePO4 cell. Most specs I have seen say 3.65 max. I have been running mine to 3.5 under the theory that less time at the top means less time for dendrites to grow. Is that what you mean by electrolyte degradation?

 

[Ampster]

Anyone see this contactor:

Yes, I used one on an EV conversion which I built years ago. Mine originally came with the motor and controller package but I did weld the contacts one time while messing around and had to buy a replacement for $100. I have a $50 smaller version that is going to go into my upgraded pack. Arcing gets pretty crazy at high volts and Amps especially with the big capacitors in some inverters. The contacts in these devices are surrounded bv arc suppressant chemicals and I think an inert gas. Well worth the money if you have an expensive pack to protect. You don't want your contacts to weld when you have a load that you need to disconnect for safety or to protect the pack.

 

[Steve_S]

Wow!... I am not sure what I said to evoke that response. Sorry if I offended in some way.

All I was saying is that relays are not my thing...so using a Chargery with relays is not something I would do. I immediately followed that with a comment that I am considering using the Chargery in situations where I can use the Chargery relay signals to directly control the charge and load devices. I also understand that others don't see the relays as a problem...and I am fine with that. We all have different situations and value sets.

I have nothing against the Chargery BMS. It is one of many options I consider when designing a system for someone. It fits well in some situations and not-so-mutch with others.

Note: The reason I am not a fan of relays is that most of the systems I do are small mobile systems where the relay energy would be a healthy percentage of the total generated power. (In the design I am considering the Chargery for, two relays would probably eat around 10% of the generated power) In addition, IMHO using the signals to directly control the load and charge is a better solution. I also have a fear (perhaps irrational) of SSR failures due to surge currents and voltage spikes.

My APOLOGIES for Snapping Off at you. Bad Hair moment you might say.

Oh I know haha! super expensive

This is another reason I avoid relay systems

But people still seem to want charge/discharge relay systems. So thought I should show the options available. I am not a fan of it at all

Have a Look at this Post I just put up, might be of interest https://diysolarforum.com/threads/ssr-testing.5347/post-73921 four posts above are links to them in that thread.

 

[Ampster]

And I wouldn't use HVD on most BMS anyways. Just run charge controller direct and set absorption manually with a coulomb meter. I trust a high quality SCC over a Chinese BMS hvd anyday. ............ HVD really isn't that crucial, especially if top balanced and as mentioned earlier, manually setting absorption

I agree that if you have a good quality charge source. Some good hybrid inverters have coulomb counters as part of their charge algorithm. Those inverters, and I assume some charge controllers, have adjustable setting for when Constant Current (Bulk) changes to Constant Voltage (Absorb) and for how long or how much the Amps have tapered.

 

[Cal]

I still don't get the point.

1. Design validation.
2. Understanding all aspects of the BMS operation.

I would never achieve those goals through your static methods. You probably already achieved those goals through the years and don't feel any reason to data log. For most of us on this forum this is the first interaction with this type of hardware. Data logging helps to get a more detailed knowledge base. OK?

Why is capacitance relevant? A LiFePO4 battery is similar to a huge capacitor. The equivalent capacitance is simple to calculate from my graph.

Using I = C dV/dt, we can calculate C (since I and dV/dt can be derived from the graph). As the battery ages capacity is lost. This will be reflected in a smaller capacitor equivalence. This data is keep for future reference to see how the battery characteristics change in the future.

What settings did I change?

The battery was charged at a constant 56A. The BMS turns the Iota converter off when cell voltage reaches 3.48V, and turns converter back on when cell voltage decays to 3.37V. In other words, the cell recovers in the span 3.48V - 3.37V = 0.11V before it turns back on. Due to cell resistance and charge current voltage drop (V = 1.5 mohm * 56A = 0.084V), there's virtually no recovery. It's all eaten up by the IR drop within the battery. We now got a free running oscillator. The reset voltage needs to be lowered. The same issue exists with the discharge reset voltage.


My setup:
180Ah battery (4 CALB cells, new)

Charging sources: solar (7A), alternator via Renogy dc/dc (40A), Iota converter (55A)

Over voltage shutdown is accomplished by the Chargery BMS. There is no big disconnect relay. Each charging source is disabled via a mA (small) relay. The BMS initiates charge termination The charging sources have a higher voltage setting than the BMS. This enables a significantly faster charge.

Loads: Biggest load is the microwave. It takes 160A. It is powered by a 2500W (ReliableElectric) inverter. I have no plans to install a low voltage disable as the inverter is only switched on when using the microwave. It is only hard wired to the microwave. Otherwise it is always off. I have taken the cover off the unit and it's would be a simple mod to install a small relay in line with the on/off switch. The switch has a ribbon cable connection, so current is very small.

Otherwise, largest load is the motor for the forced air heating. It draws 8A. I'm still looking for optimal disconnect here. Perhaps a 40A SSR or 40A latching relay.

 

[Ampster]

Note: The reason I am not a fan of relays is that most of the systems I do are small mobile systems where the relay energy would be a healthy percentage of the total generated power. (In the design I am considering the Chargery for, two relays would probably eat around 10% of the generated power) In addition, IMHO using the signals to directly control the load and charge is a better solution. I also have a fear (perhaps irrational) of SSR failures due to surge currents and voltage spikes.

That makes sense for mobile systems, especially where they are occupied when not attached to shore power. For my stationary pack there could be weeks where I am traveling and I may want to incorporate some fail safe system. I remember coming home from a trip to China a few years ago and something had happened that caused my Thundersky pack to head to zero. I wish I had installed a fail safe disconnect on that pack then. For that reason I would not use a SSR relay because when they fail they tend to fail closed.