Puredrive Battery
Comments
-
-
Would love to connect to this battery and see what the hell it is doing.
This morning started charging itself from the grid from 15% to 25% a few times until the sun kicked it.
Best guess it is getting bogus voltage from its BMS and starts to panic when it "thinks" it got to 48v (why 48? When 44v is the lowest allowed value as per Solis battery settings) and then I don't see how adding 10% of charge makes it jump to 55.6v that doesn't sound right in my books.
Only way to clear that is to power cycle the battery which is annoying - might get one of those smart finger push switches to save me the trouble.
Wish I could get a clear answer from Solis/puredrive other than SOC value is a guesstimate.
0 -
-
-
-
Advertisement
-
The puredrive dc II is a 5kwh module.
Not seeing anything out of the ordinary in the battery settings:
However when I power cycled the battery earlier today the inverter lost power too - first time I see this happen and surely with it being grid tied it shouldn't happen (I did it before at night and it did stay on)
Even weirder is that I had set the discharge SOC to 20% and it just kept on going below it, then I changed the battery mode to Backup and it stopped draining. That sort of says SOC % doesn't matter but maybe inverter looks at voltage instead?
Very hard to know what's wrong if you're not getting the right values.
If I had a night tariff it wouldn't do this I guess but I feel like it is needlessly straining the battery since it charges at 100a for a few mins, drains, charges, etc. Not to mention wasting kwh for nothing due to the conversion loses.
0 -
-
-
Solis does get voltage and current values from BMS. There are seperate registers for that. The question is though which ones it uses to make decisions. Here are both voltages within 24hours from my inverter. From what I have seen inventer overesitmates at the top or underestimates at the bottom.
The other thing is that when these unexplained charge cyscle were happening there were no alarms/warnings logged on inverter. I noticed with Seplos that when it gets to low/high voltage state, it sends that to inverter and alarm/warning is logged. This make me believie that this is purely comes from Solis and has nothing to do with battery.
In regards to battery drain it does slowly go down overtime as BMS itself is using some power but it is minimal.
0 -
Speculation: I think there's more to it than a specific voltage = a certain state of charge. Here is my cell voltage telemetry verses the reported state of charge from my GivEnergy rig.
As you can see, right this instant I have (apparently) a voltage in most cells of 3.25v and a SOC of 72%.
However, at 12:40am last night, I also had a voltage of approx 3.25v when I started to charge the battery on night rate and the SOC was ~10%. So from that I'm left to think that
a) I'm doing something wrong with the telemetry
b) there's more to it than a simple voltage= soc and there's some intelligence going on behind the scenes in the BMS to work out what the SOC is.
As to what that intelligence is.....nope, beyond my understanding, but I thought I'd share this anyway as it might give you some breadcrumbs to follow.
0 -
Advertisement
-
-
-
-
-
-
-
-
One last post re this:
This is the code that calcuates the SOC (well calculates the AH remaining, and than the SOC is calculated from that)
It will self reset itself if to 100% if the voltage of the pack is greater than the "full voltage" in the settings and current is less than 2 amps.
My charge voltage is 57V and my full voltage is 56. this is my overnight charge, went to 100% because the weather was going to be poor. The voltage of the pack
SOC/Voltage graph from last night too
0 -
-
-
Advertisement
-
-
-
-
-
Just a quick thanks for the advise on this thread I adjusted the over discharge down to 12% and the Forcecharge SOC to 10% and all appears to be working well.
Instructions for others that can hopefully help. Default pin for Solis inverter advanced settings is 0010
select in Advanced Setting_> Storage energy Set-> Battery Select, after you choose the battery model, you will be asked to set an Over-discharge SOC and a Forceharge SOC.
The over-discharge SOC is the value down to which the inverter will discharge the battery into the loads.
That will need to be set to 10% The Forcecharge SOC is the value below which the inverter will start charging a battery from the grid to avoid complete depletion.
This Forcecharge SOC must be set below the over-discharge SOC value to avoid conflict.
2 -
-
-
-
-
Advertisement
-
