Jump to content

Buying LiFePO4 cells from Lazada - Worth it or rip off time? My saga, but please add your experiences.


Recommended Posts

Posted

A Little History

Back in June 2021 we were commissioning our Sofar hybrid solar inverter, this unit needs a battery pack in order to function correctly.

 

So, in my innocence, I bought 16 x 100Ah LiFePO4 cells at 1,125 Baht a pop, along with a cheap (Daly) BMS, stuck them together in a pack with zero preparation and hooked them up. It worked!

 

Slightly later I bought my first battery capacity tester and a multi-charger, these arrived too late to actually test the pack I'd made and the BMS wasn't of the "smart" type so things were operating "blind".

 

A little later I bought 16 x 200Ah "used" LiFePO4 golf-cart cells at 1,499 Baht a pop. I spent rather a long time doing capacity tests on these. The charger could only do 6A so it was taking a day and a half to charge them, then the tester discharged at 20A. All bar one cell tested at somewhere near 160Ah (I didn't keep records I'm afraid) the remaining cell was nearer 60Ah ???? 

Of course it was way too late to complain so I ordered another cell which came out somewhere near the others. So I built a pack, added a "Smart" BMS (another Daly) and hooked them in parallel with the first lot, all worked reasonably well and I was storing around 9kWh in the two packs (treating them gently).

 

Fast-Forward to This Year

I bought a more decent Smart BMS (from Seplos) which could actually talk to the inverter. There are many discussions on the web as to whether there's any advantage, but in our case the Sofar inverter has a software bug, in that it defaults to a lead-acid profile if there's no comms. It's supposed to be adjustable, but basically ignores any settings so we weren't getting quite to a full charge.

 

Along with the Seplos I added a 5A "flying-capacitor" call balancer, hooked it all to the golf-cart cells and ran the PC software (which talks to the BMS via an RS484 converter). It rapidly became apparent that, even with the balancer, one of the cells was "a bit weak", so to help it along I hooked the "spare" cell (the one that I rejected 12 months ago) in parallel with it which improved matters a fair bit, but the parallel combo still showed as being rather low capacity.

 

Earlier This Month (Dec. 2022)

The Daly BMS on the 100Ah cells went "fzzt" and let out the Magic Smoke, it was replaced by the old non-smart unit to get the pack back online. So, the engineer in me got itchy fingers and ordered another Seplos BMS to replace the fried unit and decided that adding a further 16 x 100Ah cells to the current 100Ah pack (making it a 2P 16S arrangement) was going to be good use of my Christmas money from mummy (don't tell Madam!).

 

Meanwhile I've acquired a second 20A tester and 4 x 20A 3.65V chargers, so I can do capacity tests in a reasonable time.

 

<To be Continued>

 

  • Like 1
Posted

The Saga Continues

 

In the 18 months that the system has been operating I've bought a fair number of smaller (32650) LiFePO4 cells for various projects including our solar floodlights. The experience has shown that the quality of the cells available is somewhat "variable", ranging from "pretty decent" to "absolute carp". Even buying the same cells from the same seller didn't really guarantee anything.

 

With this in mind I bought 20 x 105Ah "Eve" cells at 1,099Baht from a seller I've used before, my idea being to capacity test them and use the best ones, along with the existing 100Ah cells (which I would also capacity test) to make the new 2P16S pack.

 

The cells arrived and were duly charged to 3.65V (full) and capacity tested at 20A down to 2.5V (totally empty). The results were somewhat disappointing. 

 

The cells ranged from 82Ah down to 55Ah ???? 

 

OK, so I can pair them "best to worst" with the existing cells.

 

When I capacity tested the existing 100Ah cells I was amazed to find that they ranged from 98Ah to 100Ah!! ???? I evidently got lucky on those.

 

Hoping to make the best of a bad job I tried ordering another 4 of the Eve cells, "no stock", even at other sellers of the same cells "no stock". It's pretty obvious that all these suppliers were drop-shipping from the same source which was now exhausted.

 

Grrr.

 

OK, so now we have a 2P16S pack which has cell-pair capacities of 165Ah to 182Ah, meaning that the best I can hope for is a total of 165Ah (or about 8kWh). Oh well ???? 

 

This pack is currently under test and calibrating the Seplos BMS.

 

I also now have the LiFePOQR app (check the Google Playstore) which can decode the QR codes on the cells and give you all kinds of useful details, manufacturer, manufacturing date, capacity etc. Unfortunately, all the cells (even the original 100Ah ones) come back with "invalid data" and a suggestion that the codes are fake ???? 

 

<More Soon>

 

 

  • Like 1
Posted (edited)

I have s/h CALB 200ah x 16 that only store about 100ah (had to buy 18)

And s/h Sinopoly 100ah x 16 that only store about 50ah (had to buy 20)

 

So your experiences are far better than mine.

If I were doing it again I'd buy new 3.7v NMS.

But in Thailand you never know what you're getting until it arrives.

 

The good news,

Even though I have my grow tent LED on from 6am to 10pm the batteries give enough o/p, to power my home from 3:30pm to 9am without taking any grid power, as long as it was a sunny day. Overcast and I'm on the grid from 6pm.

I have my cooking/showers/air-con on the grid all the time which costs me 45units/month.

Edited by BritManToo
  • Like 2
Posted
41 minutes ago, BritManToo said:

If I were doing it again I'd buy new 3.7v NMS.

 

It would be really interesting to hear the experiences of anyone who has bought these cells from Lazada.

 

Of course, they are Li-ion and so need appropriate safety arrangements (a quality BMS for starters and I wouldn't have them in the actual house).

  • Like 1
Posted

How much for the Battleborn or food batteries all the van life people and sail boat bloggers are using?  I know they are expensive.   But how can yiy expect a decent battery fir 40$.  Last lead acid battery I bought 4 months ago  was 180$ USD.  

Posted
38 minutes ago, Elkski said:

How much for the Battleborn or food batteries all the van life people and sail boat bloggers are using?  I know they are expensive.   But how can yiy expect a decent battery fir 40$.  Last lead acid battery I bought 4 months ago  was 180$ USD.  

 

You do need to compare like with like.

 

The "$40" batteries are single 3.2V cells, you need 4 of them for a 12V pack ($160) plus a BMS to protect them ($50- >$200), so we're looking at $210 for the equivalent of a 200Ah 12V lead-acid.

 

Of course, we are talking about DIYing packs here, as soon as you put a fancy box around it the $$$ goes wheeee! For example, Seplos do a 48V, 280Ah DIY kit box (with BMS but no cells) for $600, cells will add another couple of grand US.

Posted
3 hours ago, Crossy said:

 

...  as soon as you put a fancy box around it the $$$ goes wheeee! For example, Seplos do a 48V, 280Ah DIY kit box (with BMS but no cells) for $600, cells will add another couple of grand US.

sorry for the (maybe) strange question:

 

if i have a hybrid solar system installed by a thai company,
what will the quality of the battery be like?
where does a company get its batteries from?

 

@KhunLA: could you check your batteries or do you just

have to trust your installer?

Posted
37 minutes ago, motdaeng said:

sorry for the (maybe) strange question:

 

Not a strange question at all.

 

A reputable installer will probably use a branded pack (same as the inverter). Of course, you will pay for the brand name but you'll also get some kind of warranty.

  • Thanks 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.



×
×
  • Create New...