Battery Charge Speed

guybarth said:

Well, I haven't had success accessing the parameters of the batteries in order to change/increase the charge current limits. Below I show the instructions from the battery manual on how to access the settings by connecting to the Enspire software when connecting my computer to the BMS. However, I show what the Enspire software looks like when I access it, and it doesn't look the same, but more importantly, there is no option to view/change the charge current, or any parameter, of the batteries. The installer is not familiar, so we are still trying to get the supplier to help. I tried to get help directly from Hauwei, that has been a dead end so far. If anyone on this forum is smart on Hauwei batteries, please help! I'll pay Thank you

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xuhaibkhan said:

Hi there , were you able to login/access this battery’s bms ! I have the same battery but not able to connect its bms with inverter.

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1. If you only had ONE battery in the system, would it need any external device to provide proper management?
2. If no, can you disconnect them from the "hub" device such that there is no communication between them?
3. If yes, can the batteries simply be put in parallel via their primary electrical connections, like you would parallel multiple 12V batteries?
4. If yes, can they then be individually programmed to a higher charge rate?

sunshine_eggo said:

That's the same data on the huawei forum post I included before, hence why I proposed 0.15C:

https://forum.huawei.com/enterprise/en/lithium-battery-esm-48100b1/thread/667272004501389312-667213875642249216

53.25 is simply 3.55V/cell. They're permitting a little higher. It shouldn't make much difference, and either should work. I wanted to start a little on the low side to minimize triggering boost.

Their float voltage is generally regarded as unhealthy, as it has a high potential for over-charge and lithium plating holding the cells at elevated voltage. The general consensus is that 3.375V/cell is nearly ideal. Holds cells at very near 100% with no risk of over-charge. That would be 50.63V float.

When you regulate with DVCC, you can interfere with the operation of the chargers. DVCC is a single voltage. If the chargers are set higher, they never get to absorption voltage, and they won't end the bulk phase. Once you've demonstrated elevated charge current, you will need to eventually set all chargers to the same absorption voltage, absorption time and float voltage.

If this were my system, after I sorted the charge current issue, I would set to:

Absorption: 53.25V
Absorption time: 1 hr fixed.
Float: 50.63V
DVCC voltage to 53.35V (to keep it from interfering with absorption/float, but still acting as a safeguard)
DVCC current to the desired limit.

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sunshine_eggo said:

Wow. Ouch.

Whelp, at least you'll buy different batteries next time!

Questions:

1. If you only had ONE battery in the system, would it need any external device to provide proper management?
2. If no, can you disconnect them from the "hub" device such that there is no communication between them?
3. If yes, can the batteries simply be put in parallel via their primary electrical connections, like you would parallel multiple 12V batteries?
4. If yes, can they then be individually programmed to a higher charge rate?

My thinking... If each battery could operate independently with no other device needed to provide BMS protection (each battery has its own stand-alone BMS), then they should be able to operate in electrical parallel without any communications at all. If you could individually program each battery to a higher charge rate with your existing tools, then that may get you there with less pain.

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guybarth said:

Hello,

I was able to communicate directly with Hauwei a couple weeks ago. I had 3 different versions of the battery manual, and they told me which one I should use. The parameter table is below. As you can see, this chart has higher boost and float values than the chart I posted earlier. If the Hauwei rep was correct and my battery model should use this manual/chart, do you think by battery is 15s or 16s? Thank you!

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sunshine_eggo said:

100,000% 15S. They have the voltage booster so these can be paralleled with lead-acid batteries.

EDIT:

The 4800Wh Output is a dead giveaway. If it were a 16S battery, it would be 5120Wh.

15 * 3.2V = 48V
16 * 3.2V = 51.2V

48V * 100Ah = 4800Wh
51.2V * 100Ah = 5120Wh

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sunshine_eggo said:

Based on the reported behavior (it would simply raise the voltage to whatever the charger was set at when charging exceeded 0.15C), the way it seems to work to me is it uses the boost function to limit current into the battery. If it was in parallel with lead acid, it would have to raise the voltage to prevent the lead acid batteries from discharging into the lithium.

MANY server rack type batteries don't actually manage the LFP cells well - not consistent with best practices for maximum cycle life, so I don't trust that they are engaging in best practices battery management. I also see the boost function as a potential failure point - the more its used, the greater the risk of failure.

As a know-it-all, PERSONALLY, I would try the settings I recommend. If that yields acceptable results, stick with them. I would need to see expected and consistent day-to-day kWh consumption/PV production on clear days. If it doesn't, I'd grudgingly use the manufacturer's specs.

You can certainly elect to skip over everything I blabbered about and just use the manufacturer's specs. Since you're coordinating with various entities/personnel familiar with those batteries, that may be the easier option.

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guybarth said:

Hello, sorry I didn't see your question before. No, not yet. I have a Hauwei SMU BMS that connects to all of my 8 batteries. I was able to access the enspire software that the manual shows, but the menu items are not the same as the manual and the charge coefficient was not available. I wasn't able to get help from Hauwei until I somehow I got help from Hauwei in Romania. According to them and the manual they said I should use the device in the image below. My supplier in Guatemala hasn't been able to get it yet. Even if I get the device, I still need to have the software, but the Hauwei rep in Romania sent me that at least. Next, you need to have an Android device, which I don't, but my installer does.


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There is an old manual for the battery that shows connecting a special cable to the battery. Screen shot is below. That said, the Hauwei rep said this is old and not operational anymore. That said, given my lack of success getting the recommended device above, I bought the cable on Amazon. Crazy part is that the other side of the cable cannot be purchased (as far as I can tell), but my installer said he can make the cable. We'll see...

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xuhaibkhan said:

I found a video on YouTube and it seems all it needs a Lan wire and usb modified to monitor the cells and battery.

Here is the link that might help:

Also I am new to solar and batteries and this is definitely not a 16s battery it’s a 15s battery. I have tried multiple setting to avoid overcharging, and the best I have found are Float:51V and Absorbtion:51.2 (I am not running heavy load on it and it’s just 1 battery in case grid is offline)

(thanks to Steve and others who helps me and educated me about cells and voltages)

The company that installed the entire solar system at my house installed this battery, If I have known this before I would have never signed up for this battery as it doesn’t communicate with the solar inverter BMS and is connected in ‘Lead Acid’ mode.

So far I have been testing it how much charge it can hold, but to monitor it either have to get the Hauwie SBU just for this battery, or connect using the modified lan cable with laptop as in the YouTube video , not sure what language it is but captions helped)

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