Puredrive Battery

SD_DRACULA

Wanted to start a thread for a place for info for whomever has the puredrive DC batteries installed with their system.

SD_DRACULA

As a first question, does anyone know if you can connect to the battery via canbus and get live data from it?

I was trying to get a quote from a crowd which said that puredrive couldn't work out the model based on the serial number (even though I sent them the model number/SN tag/etc) and they said the only way is to connect to the battery directly.

The question is can we connect to the Down port and somehow read that? Anyone tried? What sort of cable is needed? Windows software that can read it?

Jonathan

I was wondering about that myself. Must get a multimeter at it next time I'm up and see if it is 3.3V or 5V serial port.

SD_DRACULA

The cable will be rj45 at one end but not sure if it uses something this adapter can read

https://www.amazon.co.uk/gp/product/B08CGXBSTF/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

I was able to read data via modbus from the inverter with it so if the battery uses the same protocol should work in theory

Jonathan

The DOWN port will likely speak canbus. It was the External Power Control port that I was particularly I interested in.

buzz11

https://youtu.be/fwQvQYrwf_Y

I'm interested in getting a battery and the puredrive seems a nice bit of kit but the guy in this video raises a few concerns, I'm wondering what the owners of any puredrive units think of his views?

Some of his issues relate to how it was installed but he doesn't name & shame the installer which is odd considering he's giving puredrive a lashing.

Jonathan

https://www.boards.ie/discussion/comment/118572630#Comment_118572630

That's the AC coupled battery in the the video. SD and I have the DC coupled battery and a hybrid inverter. No complaints from my side. Good battery and works well.

bullit_dodger

He's having a right whinge for sure.

A lot of what he's saying is true.... but he's not educated into the finer points of electrics. For example, he's talking about "little jimmy" needing a new plug ..... so you isolate the mains and then you get electrocuted cause your Puredrive is still on.

"Technically true", but anyone who's messing with wires and doesn't test them with a phase tester (or ideally a multimeter) to see if they are live before working on them pretty much deserves to be electrocuted in my opinion. Darwin awards etc. He also omits the fact that there is an AC isolator switch from the inverter. It's in his video at 8:00 mins (the big switch in Red) ... or the fact that it's a probably a grid-tied in inverter, and if you pull the mains then that will disconnect the battery (barring the EPS circuit)

That said, (personally) I'd like to see a circuit breaker between the battery and the inverter. Don't know if the lack of one is "non-code", but he can isolate the whole unit easy enough. Which you would have to do anyway as if it was sunny outside your inverter would be supplying the house - even if the battery was separately powered off.

The guys one of those lunatics you find on the web. He may be making "technically" correct points, but nahh.....move on Roy. Move on.

graememk

https://www.boards.ie/discussion/comment/118572767#Comment_118572767

Haven't watched the video, but it's a grid tied inverter, it has to have anti islanding, so grid is cut off, it shuts off, just like the solar inverters.

But yeah nobody should be touching stuff without safe isolation etc.

Ha Long Bay

https://www.boards.ie/discussion/comment/118572704#Comment_118572704

Just a quick question as I am not familiar with your setup are you charging the battery up on a night rate, how is the performance and any tips for import charging? I'm due to get 2 X 5KW installed next week as part of my install.

Jonathan

https://www.boards.ie/discussion/comment/118573199#Comment_118573199

Yes. Charging the battery slowly each night at about 10A. Given you'll have 10kWh, you'll have to go with a higher charge rate to ensure that you get to fully charged within the night rate window.

Ha Long Bay

https://www.boards.ie/discussion/comment/118573326#Comment_118573326

Thanks as always appreciate the advice. Do you think it would damage the batteries much if you tried to top them over a shorter time for example using a night boost rate which I imagine is for EV owners?

Just using the below graphic as an example of the type of tariff from Electric Ireland.

bullit_dodger

"Damage" isn't quiet the right word for it, but generally batteries don't like full charge/discharge. You won't wreck them or anything if you did do it for a night or two, but they prefer longer slower charges than full amps for short periods. You'll get more cycles out of them over the lifetime and they will (apparently) hold their capacity for longer. Like 10 years instead of 9 years etc.

Not sure you'll get 10Kwhr into a battery in 2 hrs though, will you? That's like ~25amps

SD_DRACULA

If you have the 5G solis inverter you can easily do that, it has 100a charge/discharge so 5kwh/hour is doable but again it would be at 1C which is what these batteries are rated for anyway.

By the way that tariff above is garbage, Bord Gais have a similar EV one with way lower rates and 3 hours for the "boost" at night meaning you could charge the battery at less than 1C

irishchris

Charge mine at 62a using the 3 hour bord gais EV charge window (2-5am @4.5c per kWh). It just charges within the 3 hours from 20% -100% and this is for 10kwh battery so as suggested above avoid that electric Ireland plan and go with the bord gais one as you will definitely need the 3 hours to charge.

Ha Long Bay

Thanks all for the helpful advice. I was just using that plan as an example of the boost rate.

bullit_dodger

62a!

ahh, in retrospect I guess I should have noted/asked for the voltage, my bad. That 62A is at ~50v though Chris isn't it? Giving you 62x50 = ~ 3Kwhr, so your three hours is ~9Kwhr. Partly the reason why I like Kwhr over amps as you have to clarify the voltage.

I was thinking your amp setting on the inverter was grid charging so your amp setting was at 220v.

buzz11

https://www.boards.ie/discussion/comment/118572630#Comment_118572630

So no real concerns about Puredrive batteries from any owners?

they're on my 'short-list' but space is going to be an issue for me (the inverter etc is all in the utility room) and their thin large profile will be tricky.

THE ALM

Happy with the puredrive as well and if I could pick up a second for decent money I will be doing so although prices for them are high.

If I could also pull the data directly and feed it into Loxone would be great but beyond my knowledge at the minute. Currently pulling it into Home Assistant then feeding it to node-red to feed it out as mqtt into Loxone so a bit convoluted.

SD_DRACULA

Apparently they have an app for it but must be apple only, as I can't find in the play store

https://www.youtube.com/watch?v=ByVx9i0hUG4

Also I'm not seeing any way to connect to it unless they offer some full system with inverter as well

THE ALM

https://www.boards.ie/discussion/comment/118580609#Comment_118580609

I wonder is it for the AC battery?

The app is in the play store and when you install it it asks for a username and password that I see no way of setting up

SD_DRACULA

Yeah I found it after looking closer as well.

Maybe here? https://puredrive-energy.co.uk/register/

SD_DRACULA

Nope just a bunch of powerpoint presentations

THE ALM

looking at the ac battery datasheet it does mention the puredrive portal so I think it is ac only

SD_DRACULA

I'd say so, I dropped them an email to confirm

On the plus side I finally figured out what flashing green light means

Also found this in the install guide:

I was told you need a "specific" cable set to daisy chain batteries together but that sounds like nonsense after reading this and everything is included with the battery as is?

Ha Long Bay

https://www.boards.ie/discussion/comment/118580583#Comment_118580583

What kind of price are you getting? I initially had a quote for a single 5KW battery and asked for a price for a second. I was quoted €2200 and agreed a price of €2000 to get it added to my upcoming install.

SD_DRACULA

https://www.boards.ie/discussion/comment/118583749#Comment_118583749

So far I got quoted 2300+ vat for adding a second one which is too much for what it is.

Also got £1600 + whatever the daisy chain cables cost from the Electrical Equipment Company up north which is better.

2k is a decent price I think. It cost me 2.5k on my install last year.

THE ALM

https://www.boards.ie/discussion/comment/118583749#Comment_118583749

Was quoted €2200 for second which is on the high side.

I'll be looking into the company in the north as I have someone who might be able to sort out something on the trade side and maybe get a better deal.

I'm in no real panic at this stage especially going into the longer days.

SD_DRACULA

https://www.boards.ie/discussion/comment/118585490#Comment_118585490

Keep us posted on how you get on with that. Maybe you can add one more to the shopping cart for me 🤣

Was told an installer needs to connect to the battery and update both of them if expanding (that's what the guys up north were told by puredrive at least)

Jonathan

https://www.boards.ie/discussion/comment/118585490#Comment_118585490

Keep me in loop as well please. Ta.

THE ALM

https://www.boards.ie/discussion/comment/118585957#Comment_118585957

will do

THE ALM

https://www.boards.ie/discussion/comment/118585530#Comment_118585530

no problem, will do.

Will call into them the next time I am up that way to get a bit more info

SD_DRACULA

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.

Jonathan

https://www.boards.ie/discussion/comment/118648571#Comment_118648571

Have you been on to your installer about it? Let them deal with Puredrive on your behalf.

SD_DRACULA

Yeah that went nowhere pretty much.

@reklamos was having the same issue and without a puredrive battery so looks like a common thing with the Solis it seems.

This is what Solis said:

So the battery management system (inside the batteries) would do estimations of SOC and after long periods of hovering at 20% odd they will be wrong.

Resetting it could help the batteries "find themselves". ​

Your batteries are not getting much energy at all. I would recommend either shutting them down during winter periods, or applying for a cheaper tariff and fully charging them during that period.

Any idea which modbus registers I can call to stop the battery from being used?

graememk

https://www.boards.ie/discussion/comment/118648571#Comment_118648571

I've been poking about with the canbus protocols, none of them actually send the battery voltage. That is measured by the inverter directly.

I wonder does the request to charge come from the battery.

Would you be able to have both the soc % and the voltage overlayed?

Or even get a multimeter on the battery terminals in the early morning?

Usually the inverter does what it is told regarding the SOC and charges. There is can codes to force a charge etc.

Remind me, what capacity is the puredrive again?

When @DrPhilG was setting up his pack I remember it being mentioned that the solis pulls some power even on standby. A clamp multi meter should be able to measure it.

SD_DRACULA

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.

irishchris

https://www.boards.ie/discussion/comment/118650358#Comment_118650358

The reason the solis would have shutdown when you power cycle the battery is that the Solis is a DC powered inverter. Therefore it only uses DC to run irregardless of it being a grid tied inverter. Those with a non hybrid Solis will see it shutdown every evening when the sun sets also

SD_DRACULA

https://www.boards.ie/discussion/comment/118651440#Comment_118651440

Yeah could be but I could swear I had the battery off at night before and it did stay on but maybe the AC backup was keeping it on (I have the option off now)?

reklamos

https://www.boards.ie/discussion/comment/118649924#Comment_118649924

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.

bullit_dodger

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.

graememk

https://www.boards.ie/discussion/comment/118652379#Comment_118652379

Oh yeah, its on CAN id 0x356 Voltage, current and Temp, Although it should be doing the actual running from its own numbers.

But your not seeing it on yours, and it doesnt happen with pylontechs, Why is it happening with Puredrive.

Its a 16s of 100ah cells, and them going to 3.4v under a 100amp charge isnt unheard of, If i push mine (400ah) cells to 120ah the voltage is well up there.

when the charge is removed it quickly settles back down.

Does it only happen when its at 15% SOC?

reklamos

LiFePO4 voltage curve is flat most of the time and only at low and high it end goes down/up. In your case at 12:40 you were charging so voltage automatically would be higher.

From what I've learned over last 2 weeks is that SOC is not exact science. I am mostly now interested in voltage of cells as this shows better picture on how the pack is doing. Also as I mentioned it does matter if the state that the cell is in idle/charge/discharge as the voltage does bounce arround.

Jonathan

@SD_DRACULA I know you have a smart meter, but can you make the numbers work if you move to BG with their 3 hour boost? That way you'd be able to charge the battery at night. I think that is the main difference between our systems.

bullit_dodger

https://www.boards.ie/discussion/comment/118652655#Comment_118652655

I get what your saying there reklamos, and to be fair, while I understand a bit of the theory here.....it's really is on the edge of my knowledge. There does seem to be some witchcraft going on there though. The 100% plateau is another interesting case. It (the voltage) spikes and then settles down. Presumably some chemistry related parameters that the BMS knows and expects and accounts for. The 3.32V range another one.

I guess what I'm saying is that there seems to be some intelligence built into the BMS which is mapping a few parameters other than the voltages and it's able to determine the soc taking all those variables into consideration, along with voltage of course.

For me, it's more of an interesting side point (I'd just like to know how it works out of curiousity). I've no real need here. In fact, when I was looking at the givenergy API I thought I wouldn't bother captureing the cell voltage, but decided "feck it - why not!"

reklamos

https://www.boards.ie/discussion/comment/118652856#Comment_118652856

It is a witchcraft. The fact that you have to tell BMS Ah of your batteries and also the deviation should be within 20Ah, make me believe as stated earlier 'SOC is not exact science'. The 100% stat is also not a set point as it does depend on the C rating that yo use to charge the baattry. The things get even more messy because there are 16 cells in the pack and they do start behave diferently at lows/highs, hence BMS tries to balance them.

For me, is similar to you if I can monitor I will, just out of interest and just in case something goes wrong at least I am not completely blind and potentialy will see what did went wrong. I would still like to better understand how it all works as this would help me to tweak my setup better. Now I do not expect to have drastic improvements but every little helps :)

graememk

https://www.boards.ie/discussion/comment/118652557#Comment_118652557

yeah you cant work out SOC from lifepo4 cells from voltage, only when your full or nearly empty is it sort of accurate. You have to columb count.

Charge to full, and then count the power in and count it out. 10 steps back and 10 steps forward should leave you at 100%!

This is the charge curve of LFP batteries, the middle is extremely flat and also influenced by charging and discharging

That's the way the zeva bms works, just counts the power in and out.

Having a good 100% mark is important, I have noticed a little bit of drift in the SOC which I've compensated for by tweaking the code and taking 1% off when it's counting the charge into the batteries

bullit_dodger

Nice one bud. Again, don't need to know this......but knowledge is power.

graememk

https://www.boards.ie/discussion/comment/118653323#Comment_118653323

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

SD_DRACULA

Yeah something weird alright, for example now the battery is at 100% SOC and 54v which seems a bit too low for a full battery doesn't it?

reklamos

https://www.boards.ie/discussion/comment/118654170#Comment_118654170

54V at 100% SOC is fine since it is not charging, you can seen only while charging it gets close to 56V