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diy solar

Checking Chargery voltage measurements

Steve_S said:
From my vault of e-mail exchanges with Jason:



12V off battery terminals apparently need the Shotky resister,
24V up should be ok, from what is gleened. I have asked for a very clear response like for 12V do this, 24V, 48V fo A or B... nope.

I want to put the packs on Batt Terminal power and have the adapters for the plugs. It occured to me though, it may be prudent to put an ON/OFF switch between the plug in and the terminal connection to kill power without having to pull the plug.

View attachment 29765
Click to expand...
the extenal power board is finished. please check the below pictures.
external1s.jpg
externals.jpg

5.5*2.1 DC connector can plug into BMS external socket directly. left connector is to connect to battery + and -, the power switch is used for power on or power off BMS. it is suitable for all Chargery BMS models.
if want this, please send me an email to jasonwang3a@163.com, now only 3 samples are available.
thanks.
 
Chargery said:
the extenal power board is finished. please check the below pictures.
View attachment 30491
View attachment 30492

5.5*2.1 DC connector can plug into BMS external socket directly. left connector is to connect to battery + and -, the power switch is used for power on or power off BMS. it is suitable for all Chargery BMS models.
if want this, please send me an email to jasonwang3a@163.com, now only 3 samples are available.
thanks.
Click to expand...
Great response Jason, have sent you an email.(y)
 
Chargery said:
the extenal power board is finished. please check the below pictures.
View attachment 30491
View attachment 30492

5.5*2.1 DC connector can plug into BMS external socket directly. left connector is to connect to battery + and -, the power switch is used for power on or power off BMS. it is suitable for all Chargery BMS models.
if want this, please send me an email to jasonwang3a@163.com, now only 3 samples are available.
thanks.
Click to expand...
Jason when my BMS is calibrated and you send it back can you add this power board in the package? What is the price?
 
Chargery said:
the extenal power board is finished. please check the below pictures.
View attachment 30491
View attachment 30492

5.5*2.1 DC connector can plug into BMS external socket directly. left connector is to connect to battery + and -, the power switch is used for power on or power off BMS. it is suitable for all Chargery BMS models.
if want this, please send me an email to jasonwang3a@163.com, now only 3 samples are available.
thanks.
Click to expand...
@Chargery
Hi Jason, can you confirm that D1 in the photo above is the 40v 3A Schottky diode? If not, would you mind telling me what i need to look for?
Thanks.
 
Solarfun4jim said:
Thanks jason. I'm going to incorporate one of those in a a homemade relay board...lol. (y)
Appreciate all your input.
Click to expand...
Just an FYI:
I put the External Power plugs on the BMS driven from the packs (-)(+) terminals, without a Shottky Diode (I'm 24V with BMS8T).
NO difference noticed in the readings. My SOC readings went kaflooie when I flipped the switch. One BMS came up with a ridiculous kAh instead of AH. Had to reset the AH values given which was a PITA and resulted in the packs reporting 99%, even though they are floating at 40% at the time...

My experiments will be more or less messed up as we are expecting no sunlight for the next week with daily snow and other. Oh well, the days will start to get longer on the 22nd...
 
Steve_S said:
Just an FYI:
I put the External Power plugs on the BMS driven from the packs (-)(+) terminals, without a Shottky Diode (I'm 24V with BMS8T).
NO difference noticed in the readings. My SOC readings went kaflooie when I flipped the switch. One BMS came up with a ridiculous kAh instead of AH. Had to reset the AH values given which was a PITA and resulted in the packs reporting 99%, even though they are floating at 40% at the time...

My experiments will be more or less messed up as we are expecting no sunlight for the next week with daily snow and other. Oh well, the days will start to get longer on the 22nd...
Click to expand...
@Steve_S
Cheers Steve. Wishing you a week of sunshine for your christmas....lol. (y)

I'm champing at the bit, waiting for a 1-25nm torque wrench and some electronic goodies to be delivered to really get going on this project...so far just done the bare minimum top balance and capacity test with the supplied busbars and screws. The real testing starts shortly(although deliveries have been getting dreadful with this virus impact).

I was hoping not to power down the BMS , but simply plug in the DC input cable and then slide the power selector from batt to ext.
Fortunately, i will be totally disregarding the chargery SOC/AH values anyway (i will rely on my victron shunt for that info).

Any idea if using the female to female jumpers on the back of an electronics breadboard are sufficient if glued into place or does everything need soldering(which is still very new to me) ?
 
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I'm going to make the following board(see below) since my RV/camper will be parked up for long periods during winter months. I want to power everything down, except the BMS, which i would prefer to be powered and monitoring cell voltages. By going this route, if my cells get too low, they trigger the LVD and in turn disconnect the BMS power to stop the drain. When i wish to power up again, i simply switch the power selector to Batt and reset parameters(but hopefully not). This means i can easily scan the voltages say once per month and have a good visual idea on the health of the cells.
Am i missing anything, any issues?

Relay board.png
 
Steve_S said:
Just an FYI:
I put the External Power plugs on the BMS driven from the packs (-)(+) terminals, without a Shottky Diode (I'm 24V with BMS8T).
NO difference noticed in the readings. My SOC readings went kaflooie when I flipped the switch. One BMS came up with a ridiculous kAh instead of AH. Had to reset the AH values given which was a PITA and resulted in the packs reporting 99%, even though they are floating at 40% at the time...

My experiments will be more or less messed up as we are expecting no sunlight for the next week with daily snow and other. Oh well, the days will start to get longer on the 22nd...
Click to expand...
@Steve_S Have you installed the 4.03 update? That resolved the problem for me where the BMS didn't maintain the SOC after a power down.
 
Yes, 4.03 Main, 4.02 LCD. All done at the same time early last week.

SOC per pack has not been right but then what I been doing to the packs, not expected to be either... but now It's time to complete the tests and get things up to snuff for final config. The Midnite is using a WinzBangJr (smart shunt attachment) which reads "bank" SOC but it's profiled for FLA/AGM and only 000.0 accurate which in Lithium Land is not very useful. They (Midnite) haven't addressed Lithium Based Chemistries as such, great SCC but "dated tech" and not keeping up, it's too bad really. Working on alternatives for myself.
 
After installing 4.03, I ran mine up to 100% and then down to about 20% and back up to around 90% a few times. The SOC is tracking pretty close on my pack now. The only issue I still have is that even though the SOC % and the WH readings are pretty close .... the AH reading is still whacky.
I've got mine sitting right now around 40% with the BMS stopped ... and monitoring with a different monitor to see how far it drifts when stored.
 
Here's what happens when I cycle BMS Power.
Using the two 174's as the example, as I just happened to do it all over again.

Upon restart of BMS:
- the internal R when cell in use stats reset (not unexpected)
- BMS 1 resets the AH remaining to 2147kAh
- BMS 2 resets the AH remaining to 4026kAh
instead of 174AH or whatever at the Top Right if the cell voltage screen.

Go to the Setup Screens, scroll down to the bottom, and change the "Battery Capacity AH" to 173, Save & Save and the AH return to normal.
I doubt accuracy there.

SOC Calculations and measurements is a bugger, Orion has FAQs as do many others in regards to accurately reading & calculating SOC.
WH is also a bit "goofy" too. The simple formula is 3.2V (nominal voltage) X #of cell X AH rating (3.2x8x100AH=2560wh.)
But it does not work does it. That "100AH" on the cell label means what ?
- Is that from 2.50-3.65V inclusive ?
- Is that just the 3.500-2.900 curve, leaving the cliff edges off ?
If you eliminate the top & bottom 5% of the cell voltage range, does that also equate to 90AH from a 100AH battery ? Yes & No... but...
3.650V-5% = 3.4675 (considered at 99%) & 2.500V+5% = 2.625 (about 2%) so, let's all be confused together with the hardware.
As it is, charge LFP to 3.65 per cell all day long to 0A taken, let it sit for an hour and they'll settle to 3.55-3.45 per cell anyways...
 
Steve_S said:
Here's what happens when I cycle BMS Power.
Using the two 174's as the example, as I just happened to do it all over again.

Upon restart of BMS:
- the internal R when cell in use stats reset (not unexpected)
- BMS 1 resets the AH remaining to 2147kAh
- BMS 2 resets the AH remaining to 4026kAh
instead of 174AH or whatever at the Top Right if the cell voltage screen.

Go to the Setup Screens, scroll down to the bottom, and change the "Battery Capacity AH" to 173, Save & Save and the AH return to normal.
I doubt accuracy there.

SOC Calculations and measurements is a bugger, Orion has FAQs as do many others in regards to accurately reading & calculating SOC.
WH is also a bit "goofy" too. The simple formula is 3.2V (nominal voltage) X #of cell X AH rating (3.2x8x100AH=2560wh.)
But it does not work does it. That "100AH" on the cell label means what ?
- Is that from 2.50-3.65V inclusive ?
- Is that just the 3.500-2.900 curve, leaving the cliff edges off ?
If you eliminate the top & bottom 5% of the cell voltage range, does that also equate to 90AH from a 100AH battery ? Yes & No... but...
3.650V-5% = 3.4675 (considered at 99%) & 2.500V+5% = 2.625 (about 2%) so, let's all be confused together with the hardware.
As it is, charge LFP to 3.65 per cell all day long to 0A taken, let it sit for an hour and they'll settle to 3.55-3.45 per cell anyways...
Click to expand...
Input the exact WH you got on the first capacity test and the AH reset itself to 100%. Now i've noted over the last couple of weeks that my Wh figure has dropped purely from the BMS 'load', with a corresponding drop in the % SOC, but the AH figure hasnt budged. I'm assuming if i charged it to full or discharged it to empty, that the AH figure would automatically be reset...but i wont be going to those values...so will simply ignore SOC/AH values.
 
Last edited:
Solarfun4jim said:
Input the exact WH you got on the first capacity test and the AH reset itself to 100%. Now i've noted over the last couple of weeks that my Wh figure has dropped purely from the BMS 'load', with a corresponding drop in the % SOC, but the AH figure hasnt budged. I'm assuming if i charged it to full or discharged it to empty, that the AH figure would automatically be reset...but i wont be going to those values...so will simply ignore SOC.
Click to expand...
That's pretty similar to my results ... except that the AH's does change. It just isn't in sync with the SOC% and the WH. Those 2 do sync pretty closely.
I can be at 50% SOC and the AH's will still be reading 60-70% of full.
 
Bob B said:
That's pretty similar to my results ... except that the AH's does change. It just isn't in sync with the SOC% and the WH. Those 2 do sync pretty closely.
I can be at 50% SOC and the AH's will still be reading 60-70% of full.
Click to expand...
My AH didnt change, because the 'BMS load' is less than 1A, so not recognised.(im still on ver4.0). The bit i dont understand, is, why does the WH value change when the system doesnt change the AH?
 
Solarfun4jim said:
My AH didnt change, because the 'BMS load' is less than 1A, so not recognised.(im still on ver4.0). The bit i dont understand, is, why does the WH value change when the system doesnt change the AH?
Click to expand...
I would update to the latest version 4.03 for the BMS and 4.02 for the display. I saw significant improvement in the voltage readings and the current when I upgraded mine.... both were a lot smoother.
There is also a lower threshold for dropping out of storage mode, but I would still like to see it even lower or eliminate storage mode all together and just allow the BMS to be powered off in charge or load mode.
 
Bob B said:
I would update to the latest version 4.03 for the BMS and 4.02 for the display. I saw significant improvement in the voltage readings and the current when I upgraded mine.... both were a lot smoother.
Click to expand...
I cant. I've tried already using an old laptop running vista and it was a complete no go. :-(
 
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