Renogy 50ah lithium battery not accepting a charge

[roadtripper]

Looking at couriers... some of them are refusing to transport Lithium batteries citing risk of fire, even though LiFE04 batteries are safer than previous technologies it would impossible for them to discern between different Lithium technologies; so I understand their position. Renogy know this, and that is why they don't want it back.

I think it's reasonable for couriers to refuse to ship warranty return lithium batteries of any kind.

I wouldn't want a known faulty battery on my airplane/truck/ship either.

The industry does need to sort that out one way or another, rather than just writing off the device and leaving it to the end user to find some way to safely recycle it.

 

[Jim Rey]

I think it's reasonable for couriers to refuse to ship warranty return lithium batteries of any kind.

I wouldn't want a known faulty battery on my airplane/truck/ship either.

The industry does need to sort that out one way or another, rather than just writing off the device and leaving it to the end user to find some way to safely recycle it.

100% agree with you!!!

 

[Jim Rey]

At last I have received a replacement battery. It was 4 weeks of persistence that paid off. Renogy need to improve their communication though. I don't think 4 weeks is perhaps a reasonable turnaround on warranty replacements. So now, at last I can get my van 12v system up and running again. Any further orders I make online will be done either via eBay or Amazon.

 

[roadtripper]

So far my experience of Amazon returns is great in the Amazon determined returns window, but appalling after that but still within statutory rights period.

I've stopped buying anything I need a warranty I can rely on from marketplace sellers, only "real" Amazon.

And I don't use eveb them for computer parts since they shipped me 2 £600 NAS drives in a jiffy bag (writing them off) then did it again with the replacements...

 

[Jim Rey]

So far my experience of Amazon returns is great in the Amazon determined returns window, but appalling after that but still within statutory rights period.

I've stopped buying anything I need a warranty I can rely on from marketplace sellers, only "real" Amazon.

And I don't use eveb them for computer parts since they shipped me 2 £600 NAS drives in a jiffy bag (writing them off) then did it again with the replacements...

Yes, I think Amazon gives you a bit more protection re warranty. I think the secret is to use the "Fulfilled by Amazon" listings. I have been using Amazon for more years than I care to remember and they have always helped me out when required.
I tested the new battery this evening and it works the way it should. The faulty battery I think was never quite right until it stopped charging completly 4weeks ago when all this started.
At least, in the end and although it took 4 weeks of effort, they have replaced it which saves me having to buy another battery elsewhere. We live and learn.

 

[Jim Rey]

UPDATE ****
The new battery has gone the same way (i.e. won't charge). I had kept the first old 50aH Renogy LIFE04 they sent so I decided to take the lid off. The BMS had switched off in protection mode so couldn't charge the battery cells. They are arranged in packs and 4 in series to give the 13.6V nominal output (i.e 4 x 3.4v)

I then disconnected balancing leads then shorted out P- and B- momentarily which reset the BMS. Measuring each of the balance leads, I could see that one group of cells was 2.8v and well under the other 3 which were close to each other in charge state voltage.

Using a variable out power supply, I decided to top charge each of the cell groups individually to bring them all up to the same 3.4v voltage. After that, the battery worked OK.

Problem is with the batteries they are sealed with glue and if any of the cell groups go out of sync then the BMS will again cut off which is what has now happened with the second battery they sent me. I can't face another email and message table tennis with Renogy again! So, next possible solution is a 4S Active Equaliser Balancer Lifepo4 Energy Transfer Board (£6.59 from Amazon). This board arrives today so I will update in due course


I will wire this in parallel with the BMS balance leads. This should hopefully keep the cells in balance and prevent the BMS going into protection mode again. This board will auto-top up any cell (where the voltage might drop close to protection BMS cut-off point) from the other cells in the array.
As I have now 2 x 50aH batteries that have done the same thing, then there obviously was an issue with either, cells that were easily going out of balance with differing internal resistances, or the BMS is inferior and not accurate enough to maintain cell groups charge states within a few mVolts of of other.

 

[Dellmassive]

Why has the battery been allowed to drop so low?

That seems to be your problem?

The BMS had shut down as a safety feature. From low cell or pack voltage.

Low voltage cells can swell which can be dangerous.

What monitoring have you got?

I've not heard of any one fitting the 50ah battery as it's so low on capacity, and you mention you have two of them?... Most people choose the 100ah up wards.

Can you post some pics of the setup, and battery etc,?

Another thing that can cause individual cells too got out of balance is high current charge or discharge cycles... So what's your loads?

And for charging you can reduce the charge rate voltage so slow down the charge speed... Ie 14.2v. so what chargers are you using,?

What version Renogy battery s, have you got the bt2 Renogy adapter to get screen shots from the BMS?

 

[Jim Rey]

These older model 50aH batteries don't have bluetooth.
My Renogy dc-dc 30A does the charging either from Solar input or ALT+
It's always been trickle charged from the solar panel so it should never have been run low.
So are LIFE04 batteries dangerous in a low voltage state?...thought these were the safest lithium technology yet.
I run sometimes a diesel heater, lights. So heater 10A at start up for a few minutes then 2A running. Lights negligible current draw.
My Eco flow Delta 2 powers everything else.
Rewiring my van as I am getting rid of rock and roll bed. so pictures not available right now.

 

[Dellmassive]

yes LIFEPO4 are the safest cell tech. . .

when looked after as instructed. . ie DO NOT LET THEM RUN 0% Flat and leave then that way.

that will 100% kill them. . . all lifepo4 manufactures state in the manual to charge monthly and fully charge every now and again to reset and BMS SoC drift.

which many short charge cycles will cause.

ie from the Renogy 50ah battery guide:

• Long periods of storage can deteriorate the battery performance. It is recommended to charge the battery "at least once every three months" to prevent over-discharge.

The "BMS will protect and shut the battery down when it is over-discharged" or short circuited. In these rarecases, the battery will show 0V voltage. Please activate the battery using an external charging source that haslithium battery activation function. Please contact our Tech Support team at (909)287-7111 for moreinformation about the BMS.

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https://www.renogy.com/content/RNG-BATT-LFP-12-50/LFP50100170-Manual.pdf

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[Dellmassive]

assuming its a

RNG-BATTLFP-12-50

charge voltage needs to be 14.4v - up to 50A charge rate ( whats yours?)

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12V 50Ah Lithium Iron Phosphate Battery

Lithium Iron Battery RNG-BATT-LFP-12-50 instruction manual, take you to understand how to use and maintain Lithium Iron Phosphate Battery

www.renogy.com

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https://www.renogy.com/content/RNG-BATT-LFP-12-50/LFP50100170-Datasheet.pdf

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looks like pouch cells . .


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[Dellmassive]

be carful of deeply discharged cells. . .

Swollen LiFePO4 Batteries? How To Prevent?

Swollen LiFePO4 batteries are the result of too much current inside a cell of the battery, which causes a build-up of heat and gas. This can be caused by overcharging, deep discharge, overheating to battery or manufacturer defects, or environmental reasons.

batteryfinds.com

Swollen LiFePO4 Batteries? How To Prevent?​

3 Comments / Lithium Battery Guides / June 17, 2021
Swollen LiFePO4 batteries are the result of too much current inside a cell of the battery, which causes a build-up of heat and gas.

This can be caused by overcharging, deep discharge, overheating to battery or manufacturer defects, or environmental reasons. In this article, we discuss why that happens and how you can prevent that.
LiFePO4 battery swelling is one of the important physical characteristics before LiFePO4 battery failure. Sometimes LiFePO4 batteries puff/swell up to twice their original size.

.

What Causes Swollen LiFePO4 Batteries?​

Causes of swollen LiFePO4 batteries

• Abuse like over charge, over discharge;
• Environmental reasons like high temperature, high humidity, ultra low pressure;
• Production process reasons.

.

2. LiFePO4 battery swollen caused by over-discharge​

LiFePO4 batteries will reversibly damage the passivation layer covering the surface of the battery after excessive discharge. The destruction of the passivation film that protects the negative electrode material will damage the negative electrode material and cause the battery to bulge.




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[Dellmassive]

you could install a shunt on the batterys, , , that will give you a 0-100% fuel gauge style ,

so you will know what the state of charge is. . .

Renogy do one now. . .

i use the Victron shunts.

bother are good and essential for a lithium battery with no BT or way of telling what the charge is. . .

The Renogy & Victron one works with the APP on your phone.

its like adding BT to your battery. . . .

I can get you a discount at Renogy United Kingdom

Hey, if you're ever looking for Renogy United Kingdom products, let me know and I can get you a discount at Renogy United Kingdom. Here's a coupon if you need one now:

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and the vicrton has the same. . .


they can also monitor the starter battery voltage,

https://amzn.to/4b33NEo

 

[Dellmassive]

so i don't think its a cell balancer you need.

i think you need a shunt to monitor the SoC - State Of Charge.

to know when the battery is low, ie around 10%,

to the enable a full charge.


lifepo4 battery's are happiest in the 20-80% range. . . but that not practical.


i normally fully charge to 100%, which has been fine,

but on the low side is try not to drop aby below 10%.


i do this with my Domestic solar batteries.

Ecoflow delta2 and other portable units,

as well as the lithium's in both vans.

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[Dellmassive]

FWIW. . .

I've had the same situation.

i had a 12v lifpo4 that we took camping. . . and left all the 12v stuff running all weekend.

i forgot about it and it run flat and cut out. . . no problem at this stage as the BMS would have allowed a charge.

but i come home and unpacked and forgot about the battery for a few weeks/months.

then when i next got it out. . . i had the same thing.

totally dead as the BMS had completely shut down due to low cell voltage. ( as the BMS consumes power all the time)


i had to open up the battery and use a variable bench supply to slowley charge each cell pack to get the battery back to life. . .


and it been fine ever since, so i what where abouts you are at. . .

my cells were very low. . . i thought that battery was toast.

but these were Grade-A Prismatic cells so top quality and recovered ok.

 

[Jim Rey]

I never ever let the batteries run low. Maybe more guilty of them sitting at 100%. I will try my cell balancer board in any case. Not going to buy shunts etc, I would buy a better battery before going down the shunt route

 

[Jim Rey]

Currently top balancing each cell group after which I will wire the equaliser board in parallel with the BMS. This will then ensure that any discharge will be uniform across the 4S array. Using shunts and battery monitors would allow me to see in detail why the BMS protection is cutting in but the equaliser board will hopefully do it’s job and for £6 a cheaper option than battery monitoring with shunt. Shunt monitoring only confirms an issue I have. However once I get the batteries operating normal I will cycle them within normal operating parameters

 

[Jim Rey]

If anyone interested in solution I am exploring see this link 4S cell balancing pcb

 

[Dellmassive]

The Renogy battery has it's own balance board built in. On the BMS board ...

Including bleed off resistors

...

And I still believe your problem is low battery voltage. ... Not sure what effect adding a second balance board will have?

But keep us posted. And post pics of your testing.

 

[Jim Rey]

The Renogy battery has it's own balance board built in. On the BMS board ...

Including bleed off resistors

...

And I still believe your problem is low battery voltage. ... Not sure what effect adding a second balance board will have?

But keep us posted. And post pics of your testing.

Useful information, thanks, but something amiss and I am not letting batteries drain so I wonder why they are dropping voltage down to 2.8v in one case of the 4S series pack. I will fit the balancing board and monitor operation. I will put a load on the battery and monitor the new balance board as DC current is drawn. There are 3 x leds on the small balance board which will light if there is an imbalance at any point. I have top balanced one of the batteries using my bench PSU and brought each cell group up to 3.4v. Will update in a few days

 

[Dellmassive]

ok, keep us posted.

but mind me asking, that if you have no shunt on the batterys,

how do you know the state of charge of them?

or whether they are full.. . or empty?

using static voltage readings is extreamly unreliable with lithiums as they basicly stay the same over 80% of the capacity range.