Just received 68 x EVE 280ah from Shenzhen Luyuan

GSXR1000

Solar Addict
Yeah I'm planning to clamp them together in their final configuration, but not when I'm top balancing them... I figured because they are being charged very slowly, the expansion will be minimal? hmm
if you let them sit fully charged they will swell a bit.. my sat for a week because of the ice storm in Texas... about ⅛ inch per cell.

next time I will build my cell then with 10 guage wire and ring terminal I will parallel them in final configuration so won't happen again
 

squowse

Solar Enthusiast
hahaha ok you made me change my mind. I’m going to hold off on top balancing until I have them clamped properly.
Trouble is that if you top balance them clamped, you're going to have to unclamp them before you're arrange them in series for discharging. I'm top balancing without clamps . Then discharge before clamping for permanent fixture to extend cycle life
 

Just John

Photon Sorcerer
hahaha ok you made me change my mind. I’m going to hold off on top balancing until I have them clamped properly.
Two suggestions.
The cheap power supply? Either get a second to double your amps, or buy a higher amp supply. Whatever you do, make some decent cables, the included alligator leads are a real hinderance. In the USA, 10 gauge wire and 1/4 inch ring terminals are easy to find in local stores or Amazon. The banana jack outside cover will unscrew, and let you place a ring terminal on it, then screw back on for a really good connection. The 1/4 inch ring terminals are also a good match for the M6 sized battery terminals. Many users have reported dramatic increases in charging (like from 4 amps to 10 amps) simply by doing this. Resist the urge to increase power supply voltage to get 10 amps, instead fix the root cause (poor connection). As Steve says, always adjust to your desired voltage while disconnected from the battery, then don't touch it.

Second suggestion. You might want to charge in groups of 4 or 8 to 3.4v and let it adsorb (in other words until current drops to less than half). That won't unduly stress cells while waiting for the rest. You are about 90 to 95% full there, so just at the start of the real curve, or just a bit below it. Once all are like that, then you can take your desired pack size (8 or 16 cells) and parallel top balance. Once top balanced and in a pack, it will take about 5 amp hours or less drawn to get them back in the 3.4v range. Just keep them in that same pack and they are top balanced.
 

davelondon

Solar Enthusiast
Whatever you do, make some decent cables

Yes I have decent cables and terminals... I was just using the crocodile clips today because the hydraulic crimper I ordered didn't arrive yet. I'll make proper cables and probably order a second PSU for the final top balance.

Next week I'm going to fabricate a mock-up of the final installation cabinet, and start to work on the clamping setup. Also I'm going to order all the Victron kit and REC BMS 😬
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
Read up on REC BMS, on here. There have been some serious issues & foibles... Nothing that cannot be resolved but a PITA nevertheless.
Every BMS regardless has some quirk or foible and sadly that is the nature of making "generic" systems to be used by DIY'ers and such.
 
did you ask Amy specifically for the black corner protectors on the boxes?
I wish she had put those on mine, my cells were all so perfect except one that took a small ding on the bottom corner. looks like the box was dropped.

I'm not sure if ill ask for any compensation as i think she has sincerely sent me good stuff. just a shipping mishap, but ill certainly let her know,
 

davelondon

Solar Enthusiast
did you ask Amy specifically for the black corner protectors on the boxes?
I wish she had put those on mine, my cells were all so perfect except one that took a small ding on the bottom corner. looks like the box was dropped.

I'm not sure if ill ask for any compensation as i think she has sincerely sent me good stuff. just a shipping mishap, but ill certainly let her know,

I didn't ask specifically for the corner protection. I always plan for a couple of damaged items in a big shipment like this, so I ordered a few spare cells.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
I go my final Air Express freight package yesterday from Amy, delivered by DHL 3 days ahead of the scheduled delivery date and I'm out in the middle of nowhere ! The packaging had the plastic corners. Amy has also just changed the way they are going to pack the cells by getting new boxes that are hardened and thicker because some of the shippers are outright abusive to the packages and she's totally fed up with that.
 

houseofancients

Solar Addict
Yes, expensive shipping to the UK is frustrating. Didn't receive any test reports with the cells.

I've unpacked 32 of the cells and they're all equally immaculate. All cells were 3.295 or 3.296 volts. They only included 1 bus bar per cell, which is not enough to connect them all in parallel, so I'm going to top balance them in two groups of 32 cells. Currently charging at 7 amps with a cheap 10A desktop charger.

View attachment 51649
what powersupply are you using if i may ask ?
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
@davelondon If you bought the Matched Grade-A cells, you do not get a printed report but ask Amy and she has that available as a download. She usually provides a link to it which pulls it from the DB. IF they were Bulk Cells, no reports as they are not Factory Matched & Batched.
 
I go my final Air Express freight package yesterday from Amy, delivered by DHL 3 days ahead of the scheduled delivery date and I'm out in the middle of nowhere ! The packaging had the plastic corners. Amy has also just changed the way they are going to pack the cells by getting new boxes that are hardened and thicker because some of the shippers are outright abusive to the packages and she's totally fed up with that.
This is good news. I was going to start a thread suggesting everyone gets Amy to use the black corner thingies, cause although its boring, it would save so many people headaches and disappointent. great to know she is motivated enough to make the improvements!
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
She is motivated because she & her husband OWN Luyuan ! Unlike the other vendors, you get to deal with working reps without a stake in the business and it's success. Amy and her hubby are what I consider as "Honourables" which doesn't mean much to Westerners (no concept of face or honour in the Chinese traditional thinking) and THAT is the reason I am happy to help them to help us collectively. Jason Wang of Chargery is also one of the rare "Honourables".
 

Just John

Photon Sorcerer
There is another thread here somewhere where this was discussed. The conclusion is that because you're able to torque the bolts much more than with the other version, you don't lose anything, and it could in fact be better.
Yes, seems there is good enough contact area, in particular using 0.5C rates and below.
That's more than enough for me, I have no desire to have my batteries only last an hour. Someone reported a 5 degrees C rise, but I get that without the welded studs during the last 40 amp hours discharge in a cell, so can't really tell if that is due to the studs, or just normal cell behavior.
Up until the last few amp hours, I was getting a 2 degree C rise in cell temperature.
 
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