Rant: EG4 48v 100ah battery has faulty BMS. Signature solar customer service is TERRIBLE

[Solar Guy Richard]

Did you see the snippet from the manual I posted several pages ago? The manual text and the spec said the same thing ... 1 second. I got that snippet from the manual that was on the web page at the time I made the post.
I don't think you are helping your case by mis-stating the facts that have been posted on this thread.

Seems like that sort of glaring error should weight this disagreement in favor of the customer instead of digging up another spec that has nothing to do with the error he was experiencing and try to blame the customer for not sizing his battery correctly.
He was able to run a number of other devices just fine with the combination of equipment he purchased.

I am getting with SS support on Tuesday to make sure all documents are looked at again and adjusted correctly. I will also review the entire ticket to see if this specific spec was in any way shape or form a decision or spoken about and adjust accordingly.

I have an entire spreadsheet with all the information for each battery clearly outlined so it will be quick work.

 

[Solar Guy Richard]

Nope. No mention of 0.1 ms anywhere. https://signaturesolar.com/content/documents/EG4/1511006-manual.pdf

Sorry, I'm looking at a manual from the factory that hasn't been made to look nice and in English like that one. It's obviously a typo or someone misunderstood the ....questionable.... formatting and syntax of the original.

 

[Bob B]

I am getting with SS support on Tuesday to make sure all documents are looked at again and adjusted correctly. I will also review the entire ticket to see if this specific spec was in any way shape or form a decision or spoken about and adjust accordingly.

I have an entire spreadsheet with all the information for each battery clearly outlined so it will be quick work.

It's pretty obvious that the erroneous 1 second delay was a significant part of the customers reasoning that the battery must be defective since the OP mentioned it in his first post on this thread.
I don't understand why it's so hard to admit that documentation error represents a significant misrepresentation of the battery capabilities and is directly related to his problem .... give the customer a full refund .... and move on.

 

[robby]

It's pretty obvious that the erroneous 1 second delay was a significant part of the customers reasoning that the battery must be defective since the OP mentioned it in his first post on this thread.
I don't understand why it's so hard to admit that documentation error represents a significant misrepresentation of the battery capabilities and is directly related to his problem .... give the customer a full refund .... and move on.

 

[HighTechLab]

late to the party, but it's quite comical...I can relate to both parties but would like to share how I would have handled this differently. I'm a business owner and encounter identical situations to the one discussed in this thread.

First off, in my opinion someone designing a system around an lv6548 should never plan to use it with just 1 battery with these specs, both capacity and capability. That's mistake #1 and had the equipment been sized appropriately, we likely never would encounter this discussion. Unfortunately that is not where this ended.

If I were handling this, I would highly recommend that the customer should purchase another battery or downsize the inverter. The simple fact is that the system is by all means severely undersized by using this inverter with just 1 battery. If the customer flat-out refuses a smaller inverter or a second battery, I too would return the battery at cost of the customer and charge a restocking fee, albeit much lower at 10% vs 30%, UNLESS I found fault in testing upon return. A business and customer must work together and be reasonable in our solutions.

Now let's say the customer does buy the second battery - It's not over. When the new battery arrives, I would highly recommend the customer test the same startup circumstances identically with the ONLY the new battery. If the issue persists, then I certainly wouldn't consider it an issue with a particular battery and would revert back to my original reasoning that 1 battery is severely undersized for the system.

HOWEVER, if the new battery runs the load just fine, I would RMA the first battery and issue a full refund, INCLUDING the shipping.

Alternatively, if the customer wants to compromise, and to compensate for the headache the customer has been dealing with, I would offer a replacement BMS for the original (faulty) battery, and on top of that I would refund the shipping of the second battery and a 20% discount on the second battery because it would be my product's fault for the trouble. Again, if the customer doesn't want to go this route, I would RMA for a full refund. (NOTE: I am not sure if the BMS is user serviceable on the EG4's like it is on the SOK's I am most familiar with.)


I've had a situation just like this with 12v batteries, it's a tough one to handle. The thing is, a logical solution and compromise that focuses on a working solution for the customer, rather than a pushing of the blame, can be reached without incurring an unreasonable expense and liability for the business or customer.

My $0.02

 

[Bob B]

late to the party, but it's quite comical...I can relate to both parties but would like to share how I would have handled this differently. I'm a business owner and encounter identical situations to the one discussed in this thread.

First off, in my opinion someone designing a system around an lv6548 should never plan to use it with just 1 battery with these specs, both capacity and capability. That's mistake #1 and had the equipment been sized appropriately, we likely never would encounter this discussion. Unfortunately that is not where this ended.

If I were handling this, I would highly recommend that the customer should purchase another battery or downsize the inverter. The simple fact is that the system is by all means severely undersized by using this inverter with just 1 battery. If the customer flat-out refuses a smaller inverter or a second battery, I too would return the battery at cost of the customer and charge a restocking fee, albeit much lower at 10% vs 30%, UNLESS I found fault in testing upon return. A business and customer must work together and be reasonable in our solutions.

Now let's say the customer does buy the second battery - It's not over. When the new battery arrives, I would highly recommend the customer test the same startup circumstances identically with the ONLY the new battery. If the issue persists, then I certainly wouldn't consider it an issue with a particular battery and would revert back to my original reasoning that 1 battery is severely undersized for the system.

HOWEVER, if the new battery runs the load just fine, I would RMA the first battery and issue a full refund, INCLUDING the shipping.

Alternatively, if the customer wants to compromise, and to compensate for the headache the customer has been dealing with, I would offer a replacement BMS for the original (faulty) battery, and on top of that I would refund the shipping of the second battery and a 20% discount on the second battery because it would be my product's fault for the trouble. Again, if the customer doesn't want to go this route, I would RMA for a full refund. (NOTE: I am not sure if the BMS is user serviceable on the EG4's like it is on the SOK's I am most familiar with.)


I've had a situation just like this with 12v batteries, it's a tough one to handle. The thing is, a logical solution and compromise that focuses on a working solution for the customer, rather than a pushing of the blame, can be reached without incurring an unreasonable expense and liability for the business or customer.

My $0.02

But .... no mention of the impact of the significant documentation error that relates directly to the problem the customer was experiencing.
To me it looks pretty straight forward .... the customer had an expectation of performance based on a flaw in the documentation.

 

[Bob B]

But .... no mention of the impact of the significant documentation error that relates directly to the problem the customer was experiencing.
To me it looks pretty straight forward .... the customer had an expectation of performance based on a flaw in the documentation.

Another more inflammatory way of wording this would be ..... false advertising .... and, while I'm not a lawyer ..... in a legal case might even result in punitive damages.

 

[OffGrid]

I know of 2 local people that have had issues with eg4 . One was trying to run a 1500 watt 12 volt inverter . That was the local dealer's fault as he knew what the customer was going to use it on .
The second case was 4 200 amp batteries and they were down for 2 weeks after installation because of bms software issues , ss definitely worked to get that fixed.
So in my opinion the batteries are not very good but I have confidence in signature solar customer support.
Unfortunately what I'm seeing is that companies willing to pay YouTube affiliates more are going to get there quality inflated greatly. .
Also I have crunched numbers on the really cheap server rack batteries and either the company's not making any money or the quality is questionable .
Just my 2 cents ! ?

 

[Solar Guy Richard]

It's pretty obvious that the erroneous 1 second delay was a significant part of the customers reasoning that the battery must be defective since the OP mentioned it in his first post on this thread.
I don't understand why it's so hard to admit that documentation error represents a significant misrepresentation of the battery capabilities and is directly related to his problem .... give the customer a full refund .... and move on.

I’d be inclined to agree with you if I had not read the dozens of emails and notes on his support ticket. I will definitely be going through them again but it was made very clear during the interaction. I am pretty well known for erring in favor of the customer, and I will continue to research this interaction specifically, to get a fair outcome.

 

[Solar Guy Richard]

late to the party, but it's quite comical...I can relate to both parties but would like to share how I would have handled this differently. I'm a business owner and encounter identical situations to the one discussed in this thread.

First off, in my opinion someone designing a system around an lv6548 should never plan to use it with just 1 battery with these specs, both capacity and capability. That's mistake #1 and had the equipment been sized appropriately, we likely never would encounter this discussion. Unfortunately that is not where this ended.

If I were handling this, I would highly recommend that the customer should purchase another battery or downsize the inverter. The simple fact is that the system is by all means severely undersized by using this inverter with just 1 battery. If the customer flat-out refuses a smaller inverter or a second battery, I too would return the battery at cost of the customer and charge a restocking fee, albeit much lower at 10% vs 30%, UNLESS I found fault in testing upon return. A business and customer must work together and be reasonable in our solutions.

Now let's say the customer does buy the second battery - It's not over. When the new battery arrives, I would highly recommend the customer test the same startup circumstances identically with the ONLY the new battery. If the issue persists, then I certainly wouldn't consider it an issue with a particular battery and would revert back to my original reasoning that 1 battery is severely undersized for the system.

HOWEVER, if the new battery runs the load just fine, I would RMA the first battery and issue a full refund, INCLUDING the shipping.

Alternatively, if the customer wants to compromise, and to compensate for the headache the customer has been dealing with, I would offer a replacement BMS for the original (faulty) battery, and on top of that I would refund the shipping of the second battery and a 20% discount on the second battery because it would be my product's fault for the trouble. Again, if the customer doesn't want to go this route, I would RMA for a full refund. (NOTE: I am not sure if the BMS is user serviceable on the EG4's like it is on the SOK's I am most familiar with.)


I've had a situation just like this with 12v batteries, it's a tough one to handle. The thing is, a logical solution and compromise that focuses on a working solution for the customer, rather than a pushing of the blame, can be reached without incurring an unreasonable expense and liability for the business or customer.

My $0.02

What we did was very close to this. Although we didn’t offer a second battery or tell the customer to get a smaller inverter (he didn’t buy the inverter from us or we would have likely made this exact suggestion), it was at the customers behest (after we informed him of the issue) to return the battery. Our tech team probably could use some training on how to sell additional equipment when it makes sense, but that’s another talk for another time. The restocking fee charged was a 20% charge, so closer to the 10% you would go with. That might change, I have some more research to do.

I do agree with some of your other points. Really, our tech team right now is very focused on immediate solutions and problem solving. It’s evolving. I’m sure if you or James or me were on this phone call, we might have made those suggestions because of experience and a wide range of knowledge in these one-off problems. I think you and me can both recognize the opportunity here to have done better from everyone’s point of view. We have grown quickly and that includes our tech department. They did the right things here to isolate the issue and inform, but that third level of knowledge and support that comes with time and experience is still being developed on our call floor. It’s constantly improving, or at least I hope so.

 

[Hedges]

I will also review the entire ticket to see if this specific spec was in any way shape or form a decision or spoken about and adjust accordingly.

Doesn't matter at all if it was spoken about. (because it was published.)
Doesn't matter what inverter manual recommends.
Doesn't matter what else this particular battery can power.

If battery spec sheet says 200A (or 250A) for 1 second, and customer's load applied less than that and battery tripped offline in under a second, that deserves 100% refund including shipping both ways. Because it failed to meet spec.

 

[Solar Guy Richard]

Doesn't matter at all if it was spoken about. (because it was published.)
Doesn't matter what inverter manual recommends.
Doesn't matter what else this particular battery can power.

If battery spec sheet says 200A (or 250A) for 1 second, and customer's load applied less than that and battery tripped offline in under a second, that deserves 100% refund including shipping both ways. Because it failed to meet spec.

I’m going to definitely research the ticket further as well as the test results. At the end of the day he shouldn’t have tried to use one battery by itself in the first place. The onus of responsibility in DIY can’t be 100% on the company or else their prices would need to be adjusted accordingly. It would be odd (to me) if a person made a purchase off of one obscure spec (short circuit timing) but ignore the obvious shortcomings of a single battery compared to what the inverter specifically calls for (AH and discharge amps) when most here can likely agree those are much more significant factors in system design. So I don’t know, on Tuesday I’ll hop in SS office, pull all the communications, the testing results, and go from there. I’m actually inclined to lean towards what you say @Hedges because you are right. Someone misplaced a period when they copied the stats and although I doubt it had any factor to this situation, I generally like customers and want them to feel good when working with Signature Solar and EG4. But, I gotta research and find out everything I can. Everyone knows I’m a customer advocate - hell, I bet some take advantage of that and me, but it’s just who I am.

 

[Hedges]

The onus is on the vendor for the battery to meet spec. (or spec to match battery.)

A 100Ah battery with 100A (1C) discharge rate and 200A surge is what people would normally expect (and charge rate 50A 0.5C). That's what the modest performance cells can usually take. So no surprise if spec sheet lists such figure. If BMS can't handle as much and spec sheet says so, then customer can select accordingly.

Disconnecting in 0.1 ms for a short is great, but we would expect that for > 2C. Would expect some seconds at < 2C, so when data sheet says so it doesn't raise eyebrows.

Short-term you can fix data sheet to be correct, but you'll have a better product if it can do 2C surge long enough to start a motor.

All these cells/batteries seem to support relatively high discharge rates and/or surge ratings.

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[12VoltInstalls]

Everything has free shipping free returns.

Nothing is free. Not even love.

Nothing is free except an individual’s intellectual capacity to de-cognify the cost of shipping and returns.

Love freely given has a cost to the giver. Love received is not free to the blessed recipient unless one is a narcissist and self-centered psychopathic manipulator. And they can’t experience the joy of blessing because they believe it’s due them

So shipping that has a real cost basis is not anywhere near free- it is merely a profit center to the seller with a fractional potential for discount. While it is a useful customer service tool due to convenience and simplicity it is certainly not free.

 

[Hedges]

What were these batteries designed for ???

I wondered why batteries for DIY solar were packaged in relatively expensive rackmount configuration.
They're meant as battery backup for computer servers in a rack!
Not as power for an AC UPS. That uses a high voltage string of batteries.
As uninterruptable 48V for power distribution unit.

They weren't designed for starting motors. They aren't expected to deliver a capacitor precharge surge because they are connected to an AC powered PDU, and keep servers running while generator start.

No wonder they are problematic for off-grid inverter applications. Such requirements weren't a consideration when they were designed.

What Signature Solar could do is define spec for the product they want to carry, e.g. 5500W continuous draw and 11000W surge for 3 seconds (to supply 5kW output of inverter with some efficiency rating.)
Be sure to specify that current draw will not be steady DC. Because load is a single-phase inverter not 3-phase, current from battery has ripple of rectified sine wave.
And precharge requirements, e.g. configurable current limit and time to charge about 1F of capacitors.
Tell manufacturer what performance is needed, and have them configure (and test/qualify) a product with suitable BMS, FET or contactor as necessary for the requirement.

You can lead the market by delivering a product that works and meets the need.

 

[JoeHam]

I know of 2 local people that have had issues with eg4 .

So in my opinion the batteries are not very good but I have confidence in signature solar customer support.

For another anecdotal report, I have been running my EG4, detailed in the post linked below, for 20 months without issue.

It is a single battery running a 4kW inverter (Schneider CSW4048). It runs my sump pump, refrigerators, garage door opener, shop vac and a ham radio amplifier that consumes about 2kW, all without issue. The amp is an unusual load since the power consumption is always on/off as I send morse code.

I rarely recount how it works without issue but thought I would throw in one positive anecdotal report.

My original post from 2020 :

100 Ah LiFePO4 @ $1250 usd. 48v nominal

Let me start by saying that I have an affliction where I read almost every post on this forum. I then wander down various paths following up on what I find interesting. I recently came across this company on one of my rabbit hole trips and I cannot remember the thread where I found this...

diysolarforum.com

 

[Ozark Tinkering]

250 A is an incredibly short trip point
We said 5000w per battery. Most people build solar systems with healthy discharge rate ratios under .5C max but ours handles 1C

You seem to be looking for a 2C ratio bms that is more like an EV battery, we don’t reach those apps as indicated by our specs.

If you used a 3000w inverter you could run your vacuum, but with the 6548 platform you are undermining the unit.

I'm thinking about purchasing the EG4 6500EX-48 and 1 EG4 48v 100ah battery. Should I anticipate a problem running my household vacuum cleaner with that setup? ...I purchased the vacuum used from op.

​

 

[HighTechLab]

It would be odd (to me) if a person made a purchase off of one obscure spec (short circuit timing) but ignore the obvious shortcomings of a single battery compared to what the inverter specifically calls for

I rarely agree with Signature Solar, but I 100% agree with Richard on this line right here.

Yes, the documentation is partially incorrect, they need to fix it - but look at every other brand. Jakiper, trophy, etc. We could sit here and find inconsistencies for months.

Even SOK battery which we all know and love couldn't figure out the difference between the > and the < sign in their spec sheet for BMS cut off voltage - I corrected it on my site, but it's been wrong on SOK's site since the beginning but we don't go 10 pages down the forum freaking out about it.

I think the whole argument that the customer bought the battery based on this spec is a load of crap and being exploited now. The inverter does NOT SPEC that running this particular vacuum mentioned in this thread would require a 250a 1s surge from the battery. It's not a real spec from the inverter! The real specs the inverter DOES have have been ignored...

Anyone familiar with NEC knows this line:

 

[Hedges]

I think the whole argument that the customer bought the battery based on this spec is a load of crap and being exploited now. The inverter does NOT SPEC that running this particular vacuum mentioned in this thread would require a 250a 1s surge from the battery. It's not a real spec from the inverter! The real specs the inverter DOES have have been ignored...

Here's the spec, what battery is supposed to do:

https://signaturesolar.com/content/documents/EG4/1511006-specs.pdf

100A constant discharge
>100A, 10 second delay
>150A, 3 second delay
>250A, 1 second delay

An inverter application is expected to have varying continuous draw, and surge capability. Many inverters spec surge of 2x nominal, so 5kW inverter might deliver 10kW. From a 48V battery, that would be 200A or so. If surge goes away within one second, this battery's spec indicates should be OK. If multiple seconds, this battery is expected to shut off. If surge is under about 7kW, draw on battery would be < 150A, should be fine for at least 3 seconds, maybe 10 seconds, should be OK.

It doesn't seem like OP's < 1kW vacuum powered by 5kW inverter should exceed these current ratings.
It may be, with a poorly filtered high-frequency inverter, that there are millisecond pulses higher than 250A to synthesize 60 Hz sine wave.
Battery spec indicates that should be ignored, but if it actually disconnects in 0.1 milliseconds, that would be the "disconnect".

I don't think "server rack" batteries were designed for inverter applications, especially single phase. I think they were designed for 48VDC PDU in a rack of computer servers.
Not designed for this application, no wonder there are problems.
We read people install a different BMS and everything is hunky-dory.
You vendors of server rack batteries for alternative energy systems ought to be setting different parameters, swapping in a different BMS, or specifying performance of a modified product to your vendors.

Either that, or very clearly (and correctly) specifying actual performance of these batteries with caveats for the application. e.g. this battery can NOT provide any surge above rated continuous output. A 100 Ah 48V 100A battery is suitable for no larger than 2kW inverter (with 4kW surge). For a 5kW or 6kW inverter, buy at least 3 batteries and connect in parallel.

 

[Hedges]

If this battery does deliver 100A continuous, 100 to 150A for 10 seconds, 150A to 250A for 3 seconds, over 250A shuts off in 0.0001 second ...
that would be plenty for reasonable operation of a 5kW inverter with 10kW surge.

We've read lots of stories of precharge issues, but not overload with modest applied load.
So it is possible OP's inverter is a unique animal that draws unfiltered PWM from battery, exceeding 250A per pulse. If so, that could explain results without anything being out of spec (beside the erroneous "250A 1 second" spec.)

It takes a fast current probe to see these spikes. Inrush function of clamp ammeter is meant to measure 60 Hz AC current, not SMPS pulses. One probe I use has 20 kHz bandwidth and can measure 2000A.