Chargery BMS News / UPDATE (Nov.25.2020) Ver 4.02 firmware

[Solarfun4jim]

Conundrum....
Powering down a RV for winter storage, ideally whereby the negative terminal on the house battery is disconnected, but the BMS is still connected/powered via the sense cables, could the BMS take a 280AH pack down below LVD over a six month period, more so if the pack was put to storage at 50% capacity? I feel this leaves my pack potentially unprotected.
On the other hand, if you power the BMS through the external input, this generally means using an AC/DC adapter, connected to the inverter, which means that it must be left permanently powered up, which in itself draws the battery down at an even higher rate. At least this way, the LVD will protect the pack.
If i completely switch off the BMS, then i assume i need to reset all the configuration settings when powered back up at a later date? I cant get the latest software updates(i'm on version 4.0 at present)
Anyone know what the parasitic drain of a BMS8T is, when sitting there measuring the voltages?

Could the diagram below work, such that i still have LVD control but not need to run inverter? I know there might be a potential issue with grounds, but dont know if this has been resolved?

 

[Bob B]

If the Chargery BMS is in storage mode .... Just press the stop button. This will de-energize the charge and load output and turn off the BMS..... I don't know what the passive draw would be in that mode, but it is very low.

Maybe @Chargery will check in an let us know what the BMS power usage is in that mode.

 

[Solarfun4jim]

If the Chargery BMS is in storage mode .... Just press the stop button. This will de-energize the charge and load output and turn off the BMS..... I don't know what the passive draw would be in that mode, but it is very low.

Maybe @Chargery will check in an let us know what the BMS power usage is in that mode.

Yes im aware of that function, but if connected through the sense wires, even at a very low draw in storage mode, you are still in reality unprotected in a low voltage situation? Take for example a situation where you think you are putting pack into storage at 50% capacity, but in reality it has been miss reported and in fact you are only at say 15% capacity...how long before you potentially run into trouble?

Like you say, we just need to know how minimal the draw is (plus you need to remember to press the stop button when shutting down...lol)

 

[Chargery]

on BMS manual there is a table that include the current drain from battery at different mode and battery voltage,
the follwing fist tabale is for BMS8T, take a 4S LiFe battery as a sample, the cell voltage at storage mode is 3.3V, total battery voltage is 13.2V, at sleep mode, the current from battery is around 28mA, if storage 6 months, the BMS will consume 120.96AH, if plus battery self discharge, the data will be more.
if turn off BMS, BMS still consume current from battery by sense voltage wire, but the current is very small, it is aroun 0.12mA(for 4S LiFe battery and cell average voltage is 3.3V), 0.45mA(for 4S LiFe battery and cell average voltage is 3.3V). at this mode, the consumption power (0.45mA drain) is under 2AH for 6 months storage.
if update BMS to V4.03 (main unit) and V4.02(LCD unit), when turn on BMS again, all setting parameters will be resumed as same before turn off, but the SOC , AH and WH reading is wrong due to battery capacity going down during storage.
obviously, 6 months is too long, in fact, for all lithium ion battery, it must be charged to 100% and then discharged to 0% every 3 months, and charge to storage voltage to continue to storage. on any lithium ion battery datasheet, the storage conditions including temperature and SOC should be found.

BMS8T:

BMS16T:


BMS24T:

 

[Solarfun4jim]

"if update BMS to V4.03 (main unit) and V4.02(LCD unit), when turn on BMS again, all setting parameters will be resumed as same before turn off, but the SOC , AH and WH reading is wrong due to battery capacity going down during storage.
obviously, 6 months is too long, in fact, for all lithium ion battery, it must be charged to 100% and then discharged to 0% every 3 months, and charge to storage voltage to continue to storage. on any lithium ion battery datasheet, the storage conditions including temperature and SOC should be found."

Great info Jason,

However the storage conditions for my particular cells datasheet suggests that 6 months storage is ok, and that the battery pack should be charged and discharged, but not necessarily from 100% to 0%(many folks just run their cells from 80% to 20% SOC permanently, for longevity reasons).

8.1 Long-term storage
Batteries should be stored (more than 1 month) indoor with a dry and clean environment at 0 ℃~35 ℃. Avoiding contact with corrosive substances and staying away from fire and heat source. The battery should be charged and discharged every 6 months. The voltage for storage is between 3. 0~3.3 V (30 ~ 50% SOC).

 

[JoeHam]

Perhaps I’m missing something but if the battery is in storage and loads are disconnected there is no benefit to keeping the BMS connected.

I would definitely disconnect the BMS for storage.

 

[Solarfun4jim]

Perhaps I’m missing something but if the battery is in storage and loads are disconnected there is no benefit to keeping the BMS connected.

I would definitely disconnect the BMS for storage.

I dont want to lose all the configuration settings, since i will not be taking the pack to 100% or 0% soc thereafter. I cant get the version 4.03 update which i believe you need to maintain the settings(from a previous post)

 

[JoeHam]

I dont want to lose all the configuration settings, since i will not be taking the pack to 100% or 0% soc thereafter. I cant get the version 4.03 update which i believe you need to maintain the settings(from a previous post)

Well I disconnected mine for storage. I can redo the settings in less than a minute.

There are YouTube videos of people who have killed their batteries in storage via BMS discharge.

Your cells,your choice though.

 

[Solarfun4jim]

Well I disconnected mine for storage. I can redo the settings in less than a minute.

There are YouTube videos of people who have killed their batteries in storage via BMS discharge.

Your cells,your choice though.

Yes i understand your reasoning, but surely after you redo the settings and then only charge to 80% soc, your readings will be all wrong, or do you charge once more to 100% SOC?

If i run my battery pack power to the external power source input, through a SSR connected to the discharge relay, then the LVD should protect me if the pack does go to low???

Edit...
To let you understand, i will only be setting up the RV electrics once and have no intention of tinkering later. I only intend to run my cells from around 3.1v/cell to 3.4v/cell, so might struggle to get to 100% SOC. I wont have any balancing function active. I'm determining the best method to power down the rv over winter.

 

[JoeHam]

Yes i understand your reasoning, but surely after you redo the settings and then only charge to 80% soc, your readings will be all wrong, or do you charge once more to 100% SOC?

If i run my battery pack power to the external power source input, through a SSR connected to the discharge relay, then the LVD should protect me if the pack does go to low???

My opinion is that the Chargery SOC is worthless at best, misleading at worst.

So I use a Victron SmartShunt.

For me the only way to avoid phantom loads is to disconnect. Stuff happens and the risk of ruining an expensive battery is not worth the reward of avoiding one minute of work.

Again, just my choice to protect my investment.

 

[Solarfun4jim]

My opinion is that the Chargery SOC is worthless at best, misleading at worst.

So I use a Victron SmartShunt.

For me the only way to avoid phantom loads is to disconnect. Stuff happens and the risk of ruining an expensive battery is not worth the reward of avoiding one minute of work.

Again, just my choice to protect my investment.

Yeah joe, i have a BMV712 for measuring my SOC. I'm using the chargery purely for the disconnect protections only. No SOC measurement or balancing.
Thanks for your input.

 

[Bob B]

I agree with the stuff happens argument .... and I also subscribe to the idea of being more careful than you think is necessary.

I also appreciate the input from Jason.

 

[Capt Bill]

in fact, for all lithium ion battery, it must be charged to 100% and then discharged to 0% every 3 months,

WOW: New Information for my Learning More All The Time Program. I did not previously know about that one. Are there any contrasting opinions? I will be putting this on my To Do List, .. while wondering how many folks never do that. Thank you for educational tip ( I think) :+)

 

[JoeHam]

.. while wondering how many folks never do that

Please add that to the list of things I will never do to my batteries ?

Your cells, your money, your choice but a hard no for me.

 

[Solarfun4jim]

WOW: New Information for my Learning More All The Time Program. I did not previously know about that one. Are there any contrasting opinions? I will be putting this on my To Do List, .. while wondering how many folks never do that. Thank you for educational tip ( I think) :+)

I wont be doing this, preferring to run between 3.1v - 3.4v/cell usage. Above 3.43/cell and my cells diverge, so i dont wish to go there.
Not sure if Jason's suggestion is simply for re calibration of the SOC/AH output values rather than for the general health of the battery???

 

[Solarfun4jim]

Conundrum....
Powering down a RV for winter storage, ideally whereby the negative terminal on the house battery is disconnected, but the BMS is still connected/powered via the sense cables, could the BMS take a 280AH pack down below LVD over a six month period, more so if the pack was put to storage at 50% capacity? I feel this leaves my pack potentially unprotected.
On the other hand, if you power the BMS through the external input, this generally means using an AC/DC adapter, connected to the inverter, which means that it must be left permanently powered up, which in itself draws the battery down at an even higher rate. At least this way, the LVD will protect the pack.
If i completely switch off the BMS, then i assume i need to reset all the configuration settings when powered back up at a later date? I cant get the latest software updates(i'm on version 4.0 at present)
Anyone know what the parasitic drain of a BMS8T is, when sitting there measuring the voltages?

Could the diagram below work, such that i still have LVD control but not need to run inverter? I know there might be a potential issue with grounds, but dont know if this has been resolved?

View attachment 30484

I realise there is a big error in my sketch above ....drawn in haste. The diagram below is my corrected one. Unfortunately i couldn't edit the original incorrect diagram.

 

[Cdkipp]

My opinion is that the Chargery SOC is worthless at best, misleading at worst.

So I use a Victron SmartShunt.

For me the only way to avoid phantom loads is to disconnect. Stuff happens and the risk of ruining an expensive battery is not worth the reward of avoiding one minute of work.

Again, just my choice to protect my investment.

Do you still use the shunt attachment with the Chargery? I have been trying to figure out if that would work. I really just want the high low cell protection.

 

[JoeHam]

Do you still use the shunt attachment with the Chargery? I have been trying to figure out if that would work. I really just want the high low cell protection.

Yes since it was connected before I got the SmartShunt. There is very little resistance so no overhead to worry about but if I ever disassemble the battery I might leave it out upon reassembly.

 

[Solarfun4jim]

Do you still use the shunt attachment with the Chargery? I have been trying to figure out if that would work. I really just want the high low cell protection.

You need the shunt for the Over Current Protection...if you dont use the chargery, you need to use another one and recalibrate the chargery to the different shunt.

 

[Chargery]

Great info Jason,

However the storage conditions for my particular cells datasheet suggests that 6 months storage is ok, and that the battery pack should be charged and discharged, but not necessarily from 100% to 0%(many folks just run their cells from 80% to 20% SOC permanently, for longevity reasons).

8.1 Long-term storage
Batteries should be stored (more than 1 month) indoor with a dry and clean environment at 0 ℃~35 ℃. Avoiding contact with corrosive substances and staying away from fire and heat source. The battery should be charged and discharged every 6 months. The voltage for storage is between 3. 0~3.3 V (30 ~ 50% SOC).

yes, differenct cell manufacture has different storage requirments, because the cell self discharge rate is different. every 3 months, battery pack discharge to 0 and charge to 100% can resume battery original capacity, discharge to 20% and charge to 80% is not the best, but it workable. when charge in 100AH, battery cannot discharge out 100Ah, why? with the cycels increase, when in 100AH, only out 90AH, because the battery meterial microstruture is damaged.
so undertand battery, using battery according to battery datasheet is very important. storage for 3 months, and do a charge-discharge deeply cycel is suggested.
almost good battery or A grade battery manufatured by famous manufactures don't sell in DIY market. the good cell must have almost same volage, same resistance and same capacity before assembel battery bank , fit with good BMS to monitor each cell volage, current, cycles, and other kinds of protecion design, all parameters is preset before delivery, warranty 2000 cycles or 3 years, not only focus on each part performance but also optimize total system performance. these battery banks are used on 5G communication base station at a large volume in China.
Chargey will be ready to provide our customer in DIY market the A grade battery bank in future.
The following picture is the 48V 100AH 16S LiFePO4 battery bank.