Gazoo's Review of the Snadi 24 Volt, 2000 Watt UPS

[Gazoo]

First of all I would like to thank @WillProwse for this forum and all of the wonderful members. I could not have made it this far without your help and I still have a ways to go, but I am getting there.

Second I would like to thank @AussieSim for his review of his Snadi which prompted me to look into the company.

Third I would like to thank @Michael B Caro for the great deal on the 8 EVE 280ah cells.

Finally, I would like to thank my Snadi contact, Camille. She was very helpful answering my questions. The language barrier can be frustrating at times but we made it.
Camille included battery cables and they are not the best, but good enough to get started and for some testing. I think they are 4AWG but they have large wire strands. I had to cut the lugs off of one end and strip the insulation so I could insert the wires into the Din Rail Terminals. I will be replacing the cables.
All of Snadi's products come in different flavors. And some can be customized. I chose a 2000 watt, 24 volt DC, 110 volt AC 60hz UPS.

Link to Snadi's Alibaba website:

Foshan Snat Energy Electrical Technology Co., Ltd.

Foshan Snat Energy Electrical Technology Co., Ltd., Experts in Manufacturing and Exporting and 0 more Products.

snadi.en.alibaba.com

1-21-21 Total paid including DHL Air and CC fee: $415.92

2-10-2021 Received Snadi on time in good condition. It arrived in a plywood box.

Discharging:

2-11-2021 The unit came with Grid Priority Mode set as the default. The default battery setting was set to U1 A.G.M.1 26.8 Volts. I have started to discharge the pack using the Snadi with the power disconnected from the grid. Average load is 375 watts.

2-12-2021 I have continued discharging the pack to see if the Snadi will shut down before the BMS hits LVD. It did not.
Capacity dropped one bar on the Snadi display when the voltage dropped to 25.03 volts, next bar 24.30, next bar 23.58. I shut the Snadi off shortly before the BMS LVD would have kicked in.

Charging:

2-12-2021 I let the battery pack rest for around an hour then started charging. Then I plugged in my loads. The max charge current of this Snadi 24 volt model is 15-20 amps and current does fluctuate a bit when charging or discharging. I am currently using the U2 A.G.M.2, 27.40 Volt setting.

2-13-2021 The voltage exceeded 27.40 volts and the Snadi display stopped indicating a charge at 27.65 volts. The current tapered off when 27.65 volts was reached. The voltage of the pack is being held at 27.68 volts. I know the float voltage is too high. Charging can be shut off but I discovered the UPS draws 300ma's even with charging shut off.

NOTE: The AGM1 setting of 26.8 volts is best for this application using LFE cells. It still goes over the 26.8 volt pre set voltage. The end of the charge is 27.07 volts and that's where it floats. I have been able to balance my cells so the highest cell floats at 3.390 volts.

Charging Profile Tests:

U0: GEL U.S.A, 27.4 Volts: Did not test. Same voltage as U2.
U1: AGM1, 26.8 Volts: Charged to 27.07 volts and the Snadi floated at that voltage.
U2: AGM 2, 27.4 Volts: Charged to 27.68 volts and the Snadi floated at that voltage.
U3: SEALED LEAD ACID, 27.2 Volts : Charged to 27.49 volts and the Snadi floated at that voltage.
U4: GEL EUROPEAN, 27.6 Volts: Did not test. Same voltage as U5.
U5: OPEN LEAD ACID, 27.6 Volts: Charged to 27.85 volts and the Snadi floated at that voltage.
U6 CALCIUM: 27.2 Volts: Did not test. Same voltage as U3.
U7: DESULPHATION: 31 Volts: Not to be used with LFE cells.
NOTE: My meter did not detect any AC ripple at the battery terminals while charging.

Inverter AC Output No Load. L=Line, N=Neutral, G=Ground :
LN = 108.6 Volts LG = 85 Volts NG = 18 Volts

Inverter AC Output 150 Watt Load:
LN = 109.7 LG = 62 Volts NG = 47 Volts.

Testing inverter AC Output using 850 Watt Load:
LN = 109.6 LG = 62 Volts NG = 47 Volts.

Ambient Temp: 73F All temps measured at highest readings. I checked temps several times.
Temp of UPS fan output: 79
Temp of DC Din Terminal - UPS Battery Input: 79
Temp of BMS cables: 83.7
Temp of fuse: 83.3
Temp of Snadi's AC outlet: 74.1
Inverter pulling 32.8 to 33.6 amps from battery. This fluctuates.
Voltage delta of cells. It fluctuates .011 - .026

I measured the AC output with a volt meter while connected to the grid and the AC output is around 1 volt less than the AC input with the inverter charging at 15 amps and an 850 watt load.

NOTE: The AC outlets installed in the UPS are rated for 10 amps or apx. 1100 watts. The UPS hard wiring input is rated for apx. 16.7 amps or 2000 watts with a 120 volt input. This slightly exceeds the output of a standard AC outlet in the US. If using a standard AC outlet I would not run the UPS much over 1500 watts. If it is hard wired into an electrical panel then it should be able to run at 2000 watts continuously. As soon as I can hard wire a power strip or something to the AC output of the UPS, I will proceed to test using a higher load than I did this test. That could be a while but I wanted to post my conclusions so far.

Likes:

1: The unit is very sturdy and the interior wiring looks good to me. It's not a Samlex or Victron but so far I like it.
2: Most of the Snadi's use a toroidal transformer. There are several advantages and disadvantages with this type of transformer. It's my understanding one of the benefits is they are more efficient.
3: The inverter idle load varies between 14 and 17 watts.
4: Easy to install the battery cables even though the unit uses Din Rail terminals.
5: Wiring the AC input was easy. I haven't wired the AC output yet but I intend to. I want to get the most power I can out of the unit mainly for testing. The UPS does supply 10 amps out of the outlets on the back which is equal to 1100 watts. Using the hard wiring of the AC output the Snadi would be limited to a total of 1800 watts which is the total the common USA outlet can supply.
6: The UPS function works great. I don't have a scope but I plugged in an old dell laptop that has no battery and when I unplugged power from the grid it didn't blink. My 55" TV doesn't blink either. So the transfer time is good.
7: The monitoring software came on an included CD. It does report the temperature of the Snadi and has a bar graph to indicate the load. Unfortunately it does not report the wattage. At least I know the serial port works which I paid an extra $5.00 for. I believe the software was compiled in 1999. It does work fine on Windows 10 and works with a serial to USB adapter.

Dislikes:

1: One case panel wasn't lined up quite right. Had to force it to get it right.
2: The top panel doesn't line up quite right with the front of the case but this is nit picking.
3: The charging profiles work but once the set voltage is reached the Snadi floats at the set charge voltage and the end of charge voltage is always a bit higher than listed in the manual.
4: I discovered the Snadi is drawing 300ma's from the battery with charging shut off.


Conclusion:
This is a very basic UPS. There are no adjustments for LVD or HVD, absorb, float or anything else other than the battery types I listed above and the charging current. For my needs it's fine and so far I feel I got my moneys worth. I know distributers can request to have firmware loaded to allow for various advanced settings. Unfortunately Camille told me they could not do this for a single order. The biggest plus of this type of UPS is the ability to add your own battery pack. Based on my experience so far I do recommend Snadi.

Support:
The only problem I am having is with the charge current. Camille told me this Snadi UPS charges in 3 stages and should charge with at least 25 amps of current. The manual indicates 30 amps. The highest charge current I have noticed is around 20 amps when I start charging my battery. But it quickly tapers off to 17.5 amps.
Camille has been working with me on this and I will report back with the outcome. She has not ignored any of my questions and we are still trying to figure out why this is happening. Personally I think it's could be a misprint in the manual.

I wasn't able to remove the top of the UPS. It's tucked in tight. I may try later.

 

[Gazoo]

More photos and the user manual:

 

[Bud Martin]

Thanks for the review.
1) Can the AC output of the inverter be readjusted to 120VAC? 110V is a little for me and it may be lowered than 110VAC at high load.
2) On the 300mA currenr draw, so if the unit is not connected to AC source, it means it will keep drawing current from batteries? I f that is the case then it looks like the batteries has to be dis connected when unit is not in used for a long time.
3) I have not decide yet which inverter I will get from them yet, trying to decide if I should spend the money making second 12V 280Ah battery pack or spending money on the inverter.

 

[Gazoo]

1) Can the AC output of the inverter be readjusted to 120VAC? 110V is a little for me and it may be lowered than 110VAC at high load.

AussieSim was able to have his adjusted from 220 to 240 so it is possible depending on the inverter. I don't know if it's possible with this one. I will be sure to check the voltage when I can up the wattage.

2) On the 300mA currenr draw, so if the unit is not connected to AC source, it means it will keep drawing current from batteries? I f that is the case then it looks like the batteries has to be dis connected when unit is not in used for a long time.

If the unit is not connected to an AC source, and all loads are disconnected then the idle draw of the inverter is 14 to 17 watts. Of course in that case the inverter will keep drawing power from the battery.

I will double check and get back to you. But as I recall if the unit is disconnected from the AC source, and shut off using the power button, then there is no current drawn from the battery.

If the unit is connected to an AC source, pressing the power button will turn off the AC output. But the unit will not power down. It will only power down completely if disconnected from an AC source.

3) I have not decide yet which inverter I will get from them yet, trying to decide if I should spend the money making second 12V 280Ah battery pack or spending money on the inverter.

That depends on what is more important to you. In the meantime I would suggest spending some time chatting with Camille. See what she can do for you and find out for sure Snadi is for you. They have a good variety of products and there are YouTube videos showing some of them. Also my unit was shipped DHL Air. It probably would have been less if shipped sea freight. The actual cost of my unit was $169.00 including the $5.00 I paid for the serial port.

 

[Gazoo]

2) On the 300mA currenr draw, so if the unit is not connected to AC source, it means it will keep drawing current from batteries? I f that is the case then it looks like the batteries has to be dis connected when unit is not in used for a long time.

I will double check and get back to you. But as I recall if the unit is disconnected from the AC source, and shut off using the power button, then there is no current drawn from the battery.

I have confirmed if the unit is not connected to AC and powered down, then there is no current being drawn from the battery.

 

[Gazoo]

Regarding charge amps this is what the engineer relayed to Camille:

"replyed from engineer :
The maximum charging current is controlled by the hardware and software. The software is modified by the computer. The maximum current on the manual generally refers to the maximum permitted by the hardware. Hardware is the circuit board. Software refers to computer software. Software is modification BY computer. These data is adjust and confirm by an adjustor before shipment."

This doesn't fully explain why the maximum charge current on my unit is 20 amps (the manual says 30 amps) and rapidly tapers to 17.5 amps. I have come to the conclusion it is what it is. As I said above, I don't think there is anything wrong with the unit. Snadi should make changes to the manual regarding this.

I have no complaints whatsoever regarding Camille. She has been with me every step of the way and has always been there to reply to my questions.

 

[John Frum]

@Gazoo for an ups 3.35 volts per is indicated.

Charging method lifepo4 280AH EVE (float or not.)

So even with an low voltage its able to charge to 100% SOC Depending on what rate you charge with, you'll get at the same state of charge at lower voltage.

diysolarforum.com

Li-Ion battery SEI layer, the critical process step in fabrication of Li-Ion batteries.

A very critical process step in the fabrication of lithum Ion chemistry batteries, including LiFePO4 battery, is the initial formation of the Solid Electrolyte Interface (SEI) layer. It is crucial in protecting electrolyte from chemical decomposition facilitating long cycle life of battery...

diysolarforum.com

Props to @RCinFLA

 

[Gazoo]

@Gazoo for an ups 3.35 volts per is indicated.

Charging method lifepo4 280AH EVE (float or not.)

So even with an low voltage its able to charge to 100% SOC Depending on what rate you charge with, you'll get at the same state of charge at lower voltage.

diysolarforum.com

Li-Ion battery SEI layer, the critical process step in fabrication of Li-Ion batteries.

A very critical process step in the fabrication of lithum Ion chemistry batteries, including LiFePO4 battery, is the initial formation of the Solid Electrolyte Interface (SEI) layer. It is crucial in protecting electrolyte from chemical decomposition facilitating long cycle life of battery...

diysolarforum.com

Props to @RCinFLA

Thanks but I have read all those posts and many other posts on this forum as well as others regarding holding cells at different float voltages. But I have also read posts of others on other forums floating cells at 3.40 volts using a UPS. They were checked later and did not have any mentionable capacity loss.

Having said that I will be testing this for myself with my cells and my system. I will be cycling at least monthly and will be keeping track. Time will tell and as I indicated I am not concerned....at least for now.

 

[John Frum]

@Gazoo Do you have a specific post to link that refutes the one I linked about the effects of voltage stress upon the SEI layer sequestering lithium?

 

[Gazoo]

@Gazoo Do you have a specific post to link that refutes the one I linked about the effects of voltage stress upon the SEI layer sequestering lithium?

No. I did not bookmark any of the other posts I read, I have no research to link to refute voltage stress, and I no where did I say I am refuting anything.

I did say I don't "think" holding a cell at 3.4 volts for an extended period of time will degrade cell capacity substantially. That's my opinion. If I start to lose a substantial amount of capacity after 3 months to a year then I will be convinced otherwise and I will post my findings.

I have seen the charts that show cell degradation when held at higher voltages but many of those are old. We will see. It's not that I am ignoring anything. I like learning by doing and in some cases have to see things for myself. I am stubborn that way and I don't mean to imply holding cells at 3.4 volt is good for the cells.

BTW, what would you consider substantial capacity loss after one year if floating at 3.4 volts?

 

[John Frum]

BTW, what would you consider substantial capacity loss after one year if floating at 3.4 volts?

I'll get back to you when I feel up to doing the amortization math on that.

 

[Gazoo]

I'll get back to you when I feel up to doing the amortization math on that.

Now that we know charging can be turned off on the Overkill BMS using the latest android app, at least I have some more control. I will keep an eye on the cells. If I start to see capacity loss I will just turn charging off on the BMS when the cells reach the set voltage.

 

[John Frum]

BTW, what would you consider substantial capacity loss after one year if floating at 3.4 volts?

I don't know.
We don't really know how much capacity loss you would have over time with these cells anyway.
I've heard estimates from 2000 cycles to 4000 cycles before the cells are at 80% of original capacity.
My guess on why we have a steady supply of inexpensive cells to the grey market is because it cheaper for the manufacturers to make more batteries than it is to dial in quality control to get higher consistency from the process.
They make more cells to ensure they have enough top quality ones for the primary market and sell the "almost good enough" cells to the cell brokers.
The real dogs should go to landfill but sometimes those get sold as well.

A wild guess would be
Lets say your 280ah cells will last 3000 cycles and test to 224ah at the end.
Lets say that you cycle once a day.
Lets say its linear degradation.
56 ah / ( 3000 cycles / 365.2422 days ) = ~6.8 ah per year.
Lets say floating high costs and extra 10% over the lifetime.
84 ah / ( 3000 cycles / 365.2422 days ) = ~10.2 ah per year.
and you end with 196 amp hours and the end.
Totally guessing of course.

 

[MisterSandals]

We don't really know how much capacity loss you would have over time with these cells anyway.
I've heard estimates from 2000 cycles to 4000 cycles before the cells are at 80% of original capacity.

I wish there were more data too!

One thing I considered in managing the number of “charge cycles” was micro-cycling. My cells settle to 3.35v in just a few minutes. When I float at 3.4v, my SCC charges every hour or two to maintain 3.4v. How these micro-cycles count towards total cycles?, I dunno.

When my RV batteries sit mostly idle in my driveway, I set float to 3.3v to prevent micro-cycling. I feel better doing this. For longer periods, I will turn off charging completely to store closer to 3.25v.

Conversely if I were a full timer or on a long trip, floating at 3.4v would keep the cells nicely topped off.

 

[Gazoo]

Conversely if I were a full timer or on a long trip, floating at 3.4v would keep the cells nicely topped off.

That's kind of what I would like to do. I just am not sure if floating at 3.4 volts for an extended period of time is going to degrade the cells. I am using my cells along with a UPS. I have no way to adjust the float voltage. The highest cell is 3.390 and the lowest is 3.375 when floating. So I will keep an eye on them to see what happens.

If I start noticing a substantial loss in capacity, and that will be awhile, I can fully charge the battery, then turn charging off on the BMS. I could also drain the cells down to a lower SOC. The only load on the battery would be from the BMS and a cheap DROK meter I have connected unless the grid fails.

I will be cycling at least monthly and I don't know if that will help prevent degradation using a 3.4 float voltage. Like you said, there is a lot of data missing.