SS EG4 12V 400AH - Disappointing BMS

[BoatGuy64]

The EG4 400AH 12V battery from Signature Solar is a beast at first glance. Its well put together but lacks the delivery you would expect with such a big battery. The documentation provided by Signature Solar shows a circuit breaker on the battery face. There isn't one on the battery they sent me. The same documentation talks about the bluetooth monitoring of the battery. Mine didn't come with bluetooth. Nobody at tech support mentions bluetooth, they just keep asking me to plug in the ethernet cable and connect it to my laptop. I have to rely on my Victron Shunt to give them any usage info. Despite these short comings and false statements I was so impressed by the build quality and @Will Prowse recommendation I decided to try it. It may look like a beast but performance is more like a pussy cat. Maximum discharge rate according to SS own specs is 200 amps, yet they throttle it with a wimpy 100 amp BMS. Really? Who does that. Its like getting a bottle of water with a pinhole to drink from. A 400ah battery that only has an output of 100amps.

I spent a week trying to figure out why my Victron Multi II 2x120 kept putting the battery into a fault. Finally I look at the specs an find out they used such a small BMS that if my inverter is at 50% capacity, it will put the battery into protect mode. Let me check the battery status using the bluetooth app, nevermind it didnt come with bluetooth.

I purchased from Signature Solar assuming a US based company would be "better" than dealing with someone offshore who just says return it, pay the shipping or buy another one. Here is the kicker, the solution provided by Signature Solar is return the battery (pay for shipping) and pay a restocking fee, or buy a second battery with a grossly undersized BMS at full retail and still be shy of what the inverter will handle.

Shame on me for not reading closer and assuming they would put a BMS that matched the substantial build of the battery. Shame on Signature Solar for not delivering the battery they advertised with a front mounted breaker, and built in bluetooth app. It took Dustin in support days to come to the realization that their battery can't perform to a reasonable expectation. They have no interest in helping make this right, so back it goes and my rating is POS.

 

[John Frum]

The spec sheet says the max charge/discharge current is 200amps constant.
I understand constant to be a synonym for continuous which is a respectable 0.5c.

https://signaturesolar.com/content/documents/EG4/1511004-specs.pdf

@BoatGuy64 are you claiming the BMS can only handle 100 amp continuous?

Tagging @RichardfromSignatureSolar

 

[BoatGuy64]

The spec sheet says the max charge/discharge current is 200amps constant.
I understand constant to be a synonym for continuous which is a respectable 0.5c.

https://signaturesolar.com/content/documents/EG4/1511004-specs.pdf

@BoatGuy64 are you claiming the BMS can only handle 100 amp continuous?

Tagging @RichardfromSignatureSolar

Yes. You fell into the same trap I did. The 200 amps cont refers to the battery module. The BMS module states 100 ah. These are copies from the spec sheet.

EG4 LIFEPOWER ADVANTAGES: This battery consists of prismatic LFP Cells, Wire, BMS, and Container ● 19” 3.5U Rack Mount Design ● Expandable up to 16 units ● Highest Performance LFP Cells with long life, safety features, and a wide temperature range ● Small Size, Light Weight, High Energy Density ● Single Cell Container is fire retardant, stable and safe ● Built-In 100AH BMS with voltage, current, temperature, and health management ● Integrated Bluetooth with APP for monitoring ● 10-20 Year Design Life ● Maintenance Free, Waterproof, 5 Year Warranty

 

[John Frum]

Yes. You fell into the same trap I did. The 200 amps cont refers to the battery module. The BMS module states 100 ah. These are copies from the spec sheet.

EG4 LIFEPOWER ADVANTAGES: This battery consists of prismatic LFP Cells, Wire, BMS, and Container ● 19” 3.5U Rack Mount Design ● Expandable up to 16 units ● Highest Performance LFP Cells with long life, safety features, and a wide temperature range ● Small Size, Light Weight, High Energy Density ● Single Cell Container is fire retardant, stable and safe ● Built-In 100AH BMS with voltage, current, temperature, and health management ● Integrated Bluetooth with APP for monitoring ● 10-20 Year Design Life ● Maintenance Free, Waterproof, 5 Year Warranty

The bms is part of the battery.
If the bms can only do 100 amps continous then the battery can only do 100 amps continuous.
@RichardfromSignatureSolar I think you should see that the doco is fixed.
That is misleading.
That spec sheet has multiple issues.

I think @BoatGuy64 has a legitimate beef.

 

[John Frum]

Yes. You fell into the same trap I did. The 200 amps cont refers to the battery module. The BMS module states 100 ah. These are copies from the spec sheet.

EG4 LIFEPOWER ADVANTAGES: This battery consists of prismatic LFP Cells, Wire, BMS, and Container ● 19” 3.5U Rack Mount Design ● Expandable up to 16 units ● Highest Performance LFP Cells with long life, safety features, and a wide temperature range ● Small Size, Light Weight, High Energy Density ● Single Cell Container is fire retardant, stable and safe ● Built-In 100AH BMS with voltage, current, temperature, and health management ● Integrated Bluetooth with APP for monitoring ● 10-20 Year Design Life ● Maintenance Free, Waterproof, 5 Year Warranty

Please post a link to this spec sheet ^

 

[Solar Guy Richard]

Hey thanks for the tag. First off, I'm going to check these numbers. The manufacturer manual states 200a continuous discharge from both the battery and the bms. If this isn't true, we need to talk with them about what is happening there. @BoatGuy64 Totally agree with you I'm going to get to the bottom of this. PM me your order info and I'll be in touch. We will either fix this or give you a full refund. I'll also make sure I don't have an outdated manufacturer manual that needs to be....englishified (a job I normally undertake anyways). This isn't sitting well with me if what you are saying is true. Where did you get the BMS discharge amperage from? I do have to say, however, that the image on our website is the correct battery and there is no breaker nor does any of the descriptions mention a breaker but ya, that manual is for the lifepower4 12v 400ah battery which we don't have in stock so not sure why they attached that to this battery. I'll get that fixed for sure tomorrow.

 

[Solar Guy Richard]

https://signaturesolar.com/content/documents/EG4/1511004-manual.pdf

Here's the link from our website.
Here's a cropped image from the manufacturer directly.

 

[Solar Guy Richard]

I just went through all the documentation on the website because I know this unit doesn't have bluetooth. Where do you see bluetooth at on the docs? We do have a 12v 100ah waterproof battery that has bluetooth but that's a completely different unit. Let me know so I can get that fixed as well.

 

[BoatGuy64]

I have attached the PDF that was given when we ordered the battery. It was then sent to me by Ethan when I called to ask again about the continuous output rating. It clearly says EG4 400 AH 12V at the top. The features list does in fact mention bluetooth app for monitoring. Further on page 2 it talks about BMS being 100AH which in fact is a misnomer since amp hour is storage and amp is current nonetheless the next diagram explains the "BATTERY MODULE SPECIFICATIONS" and states the battery dishcharge rate is 200A continous. Then Page 5 has a diagram explaining the "BMS SPECIFICATIONS:" it states discharge of >102 puts the battery into protection with a 5 second surge of >150.
Furthermore the picture and diagram on page 3 shows the breaker very clearly.

I have spent a lot of time trying to figure out why the battery can't do certain things and goes into protect mode and with the help of a clamp meter I can confirm this 400AH baterry only allows for 100A continous draw. Using ohms law thats about 1/3 of what my inverter could draw hence the reason my inverter goes into low battery mode, and the battery goes into protection mode, all the while showing a state of charge of 50 to 100%

I was willing to look into getting a second battery so I could get closer to the required 250A that would allow the inverter to max out at 3000W. Not an elegant or inexpensive solution but I was confident we could work out something. Here is the reply from your support team:

From the beginning the technicians here have thought that maybe you were asking too much out of the battery. I should have asked about the inverter sooner but it was something that I overlooked as I am still relatively new here. I have talked with my supervisors and we are not going to be able to offer you a discount on an additional battery. We are fairly certain that a new battery will resolve this "issue." The reason it is going to help is your battery can only produce 2400w instantaneously and depending on the efficiency of the inverter it can change that number slightly. We can still return the battery if you would like but you would have to pay a restocking fee and shipping. Have a nice day.

I'm hoping you can see my frustration here.

 

[SoCalKevin]

@BoatGuy64 I am also dealing with the identical issues as you.

I will say @RichardfromSignatureSolar and everyone there has been very helpful and such, but the issue still remained.

I think these issues are the manufactures fault, and not SS. SS has been awesome trying to help me.

Seems there are at least THREE different sets of specs floating around for this battery, and it seems the confusion is from the manufacture, not SS.

I have done a ton of testing here and i am agreeing 100% with your assessment the weak and poorly implemented BMS is issue.

Mine trips WAYY before the specs says it should.

I opened up my batteries and bypassed the BMS and everything seems fine now.

Personally, i would rather have the cells just connected raw than to some wonky BMS with a bunch of weird unexplained things going on that cant be adjusted.

Yeah i voided my warranty, but it is what it is. At some point, i will add a BMS back to these packs, but it most definitely wont be of the EG4 flavor.

I am also going to add a Blue Sea breaker onto mine to function as both a breaker, and an on off switch.

If you care to see my thread: https://diysolarforum.com/threads/v...lifepower-battery-compatibility-issues.38252/

 

[SoCalKevin]

https://signaturesolar.com/content/documents/EG4/1511004-manual.pdf

Here's the link from our website.

From that link: "Built-In 100AH BMS with voltage, current, temperature, and health management"

Yet, elsewhere states 200a continuous discharge. I think this is leading to a bunch of the confusion.

From all the testing i have done, 200a discharge is NOT possible here.

 

[John Frum]

From that link: "Built-In 100AH BMS with voltage, current, temperature, and health management"

Yet, elsewhere states 200a continuous discharge. I think this is leading to a bunch of the confusion.

From all the testing i have done, 200a discharge is NOT possible here.

Amp hours doesn't make sense in this context.
BMSs are rated in continous service amps.

 

[SoCalKevin]

The bms is part of the battery.
If the bms can only do 100 amps continous then the battery can only do 100 amps continuous.
@RichardfromSignatureSolar I think you should see that the doco is fixed.
That is misleading.
That spec sheet has multiple issues.

I think @BoatGuy64 has a legitimate beef.

Absolutely and i am in the same boat!

 

[SoCalKevin]

Amp hours doesn't make sense in this context.
BMSs are rated in continous service amps.

Agreed, that is cut and pasted directly from the document

 

[Solar Guy Richard]

Yea, I'm going to update these docs to be correct and in english. Sorry for the confusion, not sure who was taking control of this, but I will now. Also, I am in PM comms with the OP.

 

[BoatGuy64]

@SoCalKevin Yikes! I hope you only bypassed the BMS for a short test. It does a lot of balancing, discharge management. But you do have a good idea. If I was forced to keep this battery I would have to pull the BMS and put in my standard JDB 200A BMS with temp sensors and bluetooth. It doesnt seem realistic for an end user to void their warranty just to get a battery that operates as it should.

 

[SoCalKevin]

@SoCalKevin Yikes! I hope you only bypassed the BMS for a short test. It does a lot of balancing, discharge management. But you do have a good idea. If I was forced to keep this battery I would have to pull the BMS and put in my standard JDB 200A BMS with temp sensors and bluetooth. It doesnt seem realistic for an end user to void their warranty just to get a battery that operates as it should.

@BoatGuy64 well, its a long story, but the BMS is bypassed for a vacation i have coming up (already had to delay it a week because of this) so the batteries will be used without a BMS for about a week and i will deal with it when i get back.

My entire system is Victron components, and other than cell balancing, i have all the other parameters to protect the batteries setup through the inverter and solar charger. I honestly trust the Victron stuff to work and protect the batteries better than a wonky BMS.

When i get back from Vaca i plan to add a breaker to each battery, and see if a different BMS for cell balancing is even worth the trouble.

Cheers

 

[BoatGuy64]

@BoatGuy64 well, its a long story, but the BMS is bypassed for a vacation i have coming up (already had to delay it a week because of this) so the batteries will be used without a BMS for about a week and i will deal with it when i get back.

My entire system is Victron components, and other than cell balancing, i have all the other parameters to protect the batteries setup through the inverter and solar charger. I honestly trust the Victron stuff to work and protect the batteries better than a wonky BMS.

When i get back from Vaca i plan to add a breaker to each battery, and see if a different BMS for cell balancing is even worth the trouble.

Cheers

Victron settings won’t help if you don’t have a cell monitoring bms. If a cell underperforms at all you will overcharge the remaining cells. Charging any of those logical cells beyond 3.6 volts willl cause serious dangerous issues. If a cell drops for any reason, Victron will see your voltage as 10.8 Volts and keep pushing resulting in catastrophic failure.

 

[Mahendra Gomanie]

@BoatGuy64 well, its a long story, but the BMS is bypassed for a vacation i have coming up (already had to delay it a week because of this) so the batteries will be used without a BMS for about a week and i will deal with it when i get back.

My entire system is Victron components, and other than cell balancing, i have all the other parameters to protect the batteries setup through the inverter and solar charger. I honestly trust the Victron stuff to work and protect the batteries better than a wonky BMS.

When i get back from Vaca i plan to add a breaker to each battery, and see if a different BMS for cell balancing is even worth the trouble.

Cheers

Thats still considered third party products and a custom set up according to a battery supplier who has no inverter or safety devices of their own

 

[SoCalKevin]

Thats still considered third party products and a custom set up according to a battery supplier who has no inverter or safety devices of their own

Yes i am aware the warranty is now null and void.

At this point, its really my only option.

I have an Overkill solar BMS and blue sea 200a breaker on the way and the batteries are disconnected and out of service until then