Battery Bank Build - Deligreen 280AH EVE cells

[solardad]

Hi - Thought I would share my experience so far and upcoming journey with purchasing cells from Deligreen on Alibaba and battery bank build: https://deligreen.en.alibaba.com/co...lleryofferlist.0.0.795718a8RAd0SV#top-nav-bar

Deligreen: Main contact for me is April Cao, I believe she is the main point of contact for Deligreen Alibaba sales. My interaction so far has been good. Responsive and willing to explain details and provide technical data sheets (EVE specs.). I selected this vendor based on comment on this board from users that had a good experience.

Cells: I selected the 280AH cells purely on cost per KWH. I purchased 66 which works out to 1120AH when configured in a 4p16s setup (bought 2 spares). Paid $80 / cell at the time, end of April, so with sea shipping total cost was $6500 or $112/kwh. Pretty good deal when I was considering purchasing another Leaf pack and dealing with the unknown performance of the 'used' cells.

Shipping: Took roughly 70 days from order to delivery. Unfortunately between COVID and bumping into the May Day holiday in China it took almost 4 weeks before they were shipped out.

Packaging: Ok. I think they could've done better. When I received my order a number of boxes were beat up, holes and tears. As a result 7 of my cells were damaged beyond use, large dents and leaking fluid. This is one of my suggestions to April that they need to improve packaging. Examples:

All voltages were between 3.25 to 3.28 two except for two outliers, 3.33 and 3.15. I'll see how they act post a top balance but if needed I"ll just pair them up accordingly with stronger / weaker cells. I had very good success with that method when building my current Leaf pack - going on two years with no out of balance issues.

7 damaged cells: Working with April now to see what they can do in terms of expediting the sending of those cells. They had agreed to replace the cells but waiting to see if they can ship by air vs sea again.

I'll keep folks posted once my top balance is done and I start getting this replacement / upgrade battery bank built.

 

[solardad]

Update: Heard back from vendor and they will be shippping me replacement cells via air. I’ll be splitting the shipping cost since this is an upgrade from sea shipping. 1/2 way through balancing the cells that I have, settling in nicely at 3.6v. Took almost 3 days with a 10a charger, DC charger. Working out now my storage of the bank while I let the cells rest so I can match them appropriatel.

 

[Dauntless]

I too, just received 4 cells from Deligreen I bought the 200 ah cells for $80 each +
3.2V CATL 200AH LifePO4 cells 4x $85
4853404S12V 200A LifePo4 BMS with common port $118
1118118Ship by Sea:door to door, tax and duty free, 1 month after ship leave $155
Total Cost $613

My box was shipped to Seattle and then I had to pay $58 to get it to Alaska on the barge a week later.

All in all, I was very pleased with Deligreen. THere were no surprises and the batteries were very well packed.
Looks like a few of Solardads boxes above were dropped;

My box came in perfect condition.

 

[Bleedingblue]

Update: Heard back from vendor and they will be shippping me replacement cells via air. I’ll be splitting the shipping cost since this is an upgrade from sea shipping. 1/2 way through balancing the cells that I have, settling in nicely at 3.6v. Took almost 3 days with a 10a charger, DC charger. Working out now my storage of the bank while I let the cells rest so I can match them appropriatel.

On that charger you just set it to 3.6 and it charged them all up and the cells balanced out? I'm asking because I do not have one and never have messed with it. But I have some cells coming sometime this month or next.


Also what kind of BMS are you going to use? Is it going to communicate with the charge controller?

 

[solardad]

On that charger you just set it to 3.6 and it charged them all up and the cells balanced out? I'm asking because I do not have one and never have messed with it. But I have some cells coming sometime this month or next.


Also what kind of BMS are you going to use? Is it going to communicate with the charge controller?

Given the number of cells I maxed out the charger to 10amps for the bulk of the charger. This speeds up the process but you need to closely monitor. Reason being this charger only allows for constant current (amps) or voltage. If you do current then it’ll just keep on pumping the amps out regardless of volts, how my overcharge happened. If you do consent voltage then it’ll charge at a lower current and taper down the current when it reaches the set voltage, safer but takes longer. Read the manually carefully since the settings on the charger I found finicky at first. In short there is a light for the voltage knob and current knob the only way to tell which setting the charger is set to is the light. I believe it was a green light for voltage and orange/red for current.

I plan on using Charger 16T based on the reviews here. Was looking at the Batrium but decided to go this route. My charge controller is dumb, only reads the cell values at this time so I plan on leveraging the Chargery relays for my low / high voltage disconnects if needed.

 

[Bleedingblue]

Given the number of cells I maxed out the charger to 10amps for the bulk of the charger. This speeds up the process but you need to closely monitor. Reason being this charger only allows for constant current (amps) or voltage. If you do current then it’ll just keep on pumping the amps out regardless of volts, how my overcharge happened. If you do consent voltage then it’ll charge at a lower current and taper down the current when it reaches the set voltage, safer but takes longer. Read the manually carefully since the settings on the charger I found finicky at first. In short there is a light for the voltage knob and current knob the only way to tell which setting the charger is set to is the light. I believe it was a green light for voltage and orange/red for current.

I plan on using Charger 16T based on the reviews here. Was looking at the Batrium but decided to go this route. My charge controller is dumb, only reads the cell values at this time so I plan on leveraging the Chargery relays for my low / high voltage disconnects if needed.

Since i have 48 -280 AH cells it should take a while then. You do all yours at once or charge em in batches?

 

[Craig]

Since i have 48 -280 AH cells it should take a while then. You do all yours at once or charge em in batches?

I charge 8 at a time with a 30 amp bench charger. It only takes about a day to get to 3.65v

 

[Ampster]

Read the manually carefully since the settings on the charger I found finicky at first. In short there is a light for the voltage knob and current knob the only way to tell which setting the charger is set to is the light. I believe it was a green light for voltage and orange/red for current.

That is very important information. In addition, when setting voltagen when connected to a cell or cells, a button needs to be pushed so the voltage on the dial is the target, not the voltage of the cell or cells connected. Been there done that and overcharged a few myself.

 

[solardad]

Since i have 48 -280 AH cells it should take a while then. You do all yours at once or charge em in batches?

Initially I did a batch of 6 and then another batch of 6. First 6 I screwed up and over charged but brought down quickly. Second batch i figured out the charger and had a good charge. Batch 1 and 2 were roughly 3.55-3.6. Still had 20 to go so I charged those to 3.6 all in parallel (at max amps, 10) and then paralleled the other 12 into one overall 32 cell bank and did a set voltage charge to 3.65, roughly 1-2amps that tailed off once it hit 3.65 - took almost 8-12 hrs. I then let the bank rest overnight still paralleled and the voltage was 3.6. From there I wanted to see if I had any outliers so I disconnected every cell and measured the voltage and then again 24 hrs later and tagged which ones were more than 2mv from the average, 2 cells. Now I have a baseline in combining my cells so the pack will hopefully stay in balance naturally.

In short if I was to do it over again I would’ve just parallel the overall bank and did the charge. The most important steps are the last couple since you can confirm which cells are naturally strong or weak, aka internal resistance outside of the pack average.

Edit: might make sense if I mention that my packs will be 2p16s thus the reason for the earlier comment about ‘combining cells’. Still have another 32 cells to top balance.

 

[Ampster]

still paralleled and the voltage was 3.6.

Maybe these take longer to get to resting voltage than my other experiences.
Thanks for the update. I am away for a few more days before I can share any more experience.

 

[solardad]

Maybe these take longer to get to resting voltage than my other experiences.
Thanks for the update. I am away for a few more days before I can share any more experience.

Possible, but I just checked again individual cells (now 36hrs since they were all paralleled) and they range from 3.58 to 3.60 with one outlier at 3.55. I think this makes sense when you consider the discharge curve for the cells - initial drop off then basically flat.

 

[Ampster]

That is different from my experience with Winstons and Thunderskys. However the settled voltagemof 3.2 to 3.3v is consistent with the voltage that my LFP 280 cells were at when they arrived.

 

[Ampster]

I checked my Nissan Leaf charging data and only see less than 0.1 volt drop so they don't settle like the LFPs I used to have. That was historical data while connected to my inverter. When I get back I am going to look at some of the Leaf modules that have been charged to 4.2v and sitting static since then. I also got notice that my IR tester arrived.

 

[solardad]

That is different from my experience with Winstons and Thunderskys. However the settled voltagemof 3.2 to 3.3v is consistent with the voltage that my LFP 280 cells were at when they arrived.

I think a 3.2-3.3 will eventually happen to the cells but not sure how long it’ll take - months..??

 

[Bleedingblue]

Initially I did a batch of 6 and then another batch of 6. First 6 I screwed up and over charged but brought down quickly. Second batch i figured out the charger and had a good charge. Batch 1 and 2 were roughly 3.55-3.6. Still had 20 to go so I charged those to 3.6 all in parallel (at max amps, 10) and then paralleled the other 12 into one overall 32 cell bank and did a set voltage charge to 3.65, roughly 1-2amps that tailed off once it hit 3.65 - took almost 8-12 hrs. I then let the bank rest overnight still paralleled and the voltage was 3.6. From there I wanted to see if I had any outliers so I disconnected every cell and measured the voltage and then again 24 hrs later and tagged which ones were more than 2mv from the average, 2 cells. Now I have a baseline in combining my cells so the pack will hopefully stay in balance naturally.

In short if I was to do it over again I would’ve just parallel the overall bank and did the charge. The most important steps are the last couple since you can confirm which cells are naturally strong or weak, aka internal resistance outside of the pack average.

Edit: might make sense if I mention that my packs will be 2p16s thus the reason for the earlier comment about ‘combining cells’. Still have another 32 cells to top balance.

I guess I'm planning on combining all 48 of mine and balancing all at once.

 

[Ampster]

I think a 3.2-3.3 will eventually happen to the cells but not sure how long it’ll take - months..??

Good question. I have some extra cells so I might charge one to 3.4 and another to 3.5 and log their voltages over several days to see.

 

[solardad]

Update: So I have half of my cells up and running in a 2p16s configuration, so far so good.

I originally was going to do a cabinet but ended up leveraging an existing shelf that I had my old battery bank on, Chevy Volts packs. The location is limited in size so the shelving should be ideal, two shelves of banks at 2p16s. Ended up re-enforcing the shelves with 3/4 plywood.



After wired up and balance wires in place.



Terminal block for balance wires and Active balancer and Chargery BMS. The relay still needs to be hooked up. The balance function of the Chargey is really not relevant for a pack at this size when compared to the performance of the active balancer. I ran a few basic tests and it was able to balance the pack down to a cell delta of 4-6mv from 25-27mv over the course of 8-10 hours. I would normally be happy in the 20-30mv range given my pack high and low settings are, 54.6v and 48v or 3.4125v to 3, just below and above the cell knees.



Active balancer screen with cell details:

 

[Ampster]

Looking good.

 

[solardad]

Looking good.

Thanks.

Forgot to mention that Deligreen and April came through with the replacement cells that were damaged by FedX. I received 7 replacement cells by air through UPS. Condition of all the cells was perfect!

 

[ArthurEld]

April told me someone else bought 66 cells for $80 each.
I paid $6641 including shipping and the PayPal transaction fee for 66 cells from Deligreen.
Hopefully they will arrive in a month.
I saw your box tore up. They made the nice spongy battery holders but it makes the whole box spongy by the time it gets here.