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Hello guys I'm new here. I work for a China battery company and I guess I know something you're interesting in. Ask whatever you wanna know

AshleyL said:
I am more interested with the gray market questions.
I understand the best batteries are reserved for those high end automotive or stationery energy storage stuff.
How about those cells that don't pass the test? There are many questions I like to ask about these "unwanted" cells that currently in gray market.3

  1. Why are those cells "discarded"?
  2. What kind of tests that make those cells failed to be qualified?
  3. Why company doesn't simply recycle those failed cell, yet they auctioned those and many unscrupulous people "relasered" it to trick people?
  4. Why the manufacture does have DIRECT TO Customers sales?
Click to expand...

Both automotive batteries and energy storage batteries are classified differently due to their different focuses. Automotive batteries emphasize power density, while energy storage batteries emphasize energy density. Here is the response to your questions:

1. Batteries are typically graded during production, with those meeting the target requirements classified as Grade A. Batteries with higher internal resistance or higher self-discharge rates are classified as Grade B. Depending on the quality, there may even be Grade C and D. Qualified products are retained, while non-qualified products are typically destroyed(under normal circumstances).

2. Testing is usually based on the battery's performance in meeting standards, such as internal resistance, capacity, self-discharge rate, etc. Specialized tools are often required for testing.

3. This topic involves economic issues and is a microcosm of the entire economic world. Non-qualified products don't necessarily mean they are completely unusable. For small businesses, production capacity and quality control are often not high, resulting in a higher rate of non-qualified batteries. If, as you suggest, every non-qualified battery is discarded, the cost would become very high. The increased production cost would then be passed on to consumers. Assuming the market price is generally 1 USD, but the non-qualified rate increases production costs, even exceeding 1 USD. Do you think consumers would bear the cost? If not, businesses would close, creating a serious problem. Large enterprises also face this issue, having evolved from small enterprises.

4. This issue is strategy-oriented. Traditional manufacturing industries generally don't directly sell to end consumers because their focus is on manufacturing and research and development. Face-to-face sales are typically within the scope of brand merchants. However, you can see new manufacturing industries engaging in customer marketing. This strategy allows them to gain more partners. When consumers choose products manufactured by XXX, it forces distributors and brand merchants to actively contact XXX, helping them expand their sales network because it is profitable in this network. Regardless of whether the manufacturing industry directly markets to end customers, there is a bottom line—they will not disclose prices to end customers. This means no profit for distributors. It is good for consumers but disastrous for manufacturers because manufacturers have limited access to customers, while distributors can take products worldwide, as long as it's profitable.
 
hwy17 said:
In the battery business in China do people talk about the market for DIY batteries and customers purchasing raw cells, or is it so small that it is mostly ignored?
Click to expand...
Chinese consumers also buy battery cells for assembly, whether out of interest or practicality. However, the number of people doing so is limited. Assembled products are typically used for small devices, such as replacing batteries in solar-powered lights or swapping batteries for electric bicycles. For outdoor portable power sources, only a very small number of enthusiasts engage in DIY, as it requires higher technical expertise beyond the simple connection of positive and negative terminals. If one buys battery cells, they also need to be matched, which demands specialized tools. Therefore, DIY batteries exist, but this segment of the population currently constitutes a small proportion. It is also possible that I may have made an inaccurate judgment due to not being involved in their community.
 
Battery_Kate said:
Chinese consumers also buy battery cells for assembly, whether out of interest or practicality. However, the number of people doing so is limited. Assembled products are typically used for small devices, such as replacing batteries in solar-powered lights or swapping batteries for electric bicycles. For outdoor portable power sources, only a very small number of enthusiasts engage in DIY, as it requires higher technical expertise beyond the simple connection of positive and negative terminals. If one buys battery cells, they also need to be matched, which demands specialized tools. Therefore, DIY batteries exist, but this segment of the population currently constitutes a small proportion. It is also possible that I may have made an inaccurate judgment due to not being involved in their community.
Click to expand...
Did you notice the title of this Forum when you joined?
 
OffGridForGood said:
@Battery_Kate - I am reading all your comments and learning some new information too - thankyou for taking the time to join the DIY Solar Forum, and writing to us.
I would like to know if your company is working on a Sodium Battery cell for distribution?
Click to expand...
No we mainly focus on LFP battery cause the mother company is the cathode materials provider. But sodium battery seems to be a new trend? Another guy asking me about the sodium battery before and I did some research. There are some companies working on it and I will share it at here. Information is collected from China Social Media.1705456099457.png
 
OffGridForGood said:
@Battery_Kate - I am reading all your comments and learning some new information too - thankyou for taking the time to join the DIY Solar Forum, and writing to us.
I would like to know if your company is working on a Sodium Battery cell for distribution?
Click to expand...
What do you think of the sodium battery? I'm not so familiar with this and hope to learn more too.
 
Very interesting - thank you for the contact information Kate.

With LFP cells, I am mostly interested in the Prismatic cells, for building my own "48 volt" (nominal 51.2 volts) battery packs for use with stationary solar energy storage. For my applications I do not need cells that meet the automotive industry requirements, I am happy to have cells that will provide suitable energy density for my solar energy and I like being able to get these lower classification cells for lower cost per cell,
BUT!
Myself, and many of the the forum members here, become concerned about 'what are we getting'. That is to say, I am happy to get "grade B" cells for my solar energy storage for a lower price, but I worry about getting "Grade C or D" but paying Grade B prices.
We have seen EVE are now marking cells with a B on them to indicate the storage grade cells - does your company have plans to also mark the storage grade cells with a marking so consumers know what we are getting for our money?
 
Battery_Kate said:
What do you think of the sodium battery? I'm not so familiar with this and hope to learn more too.
Click to expand...
I live in Canada, where we have lot of cold weather.
The Sodium cells, from what I read, are able to charge and discharge at lower temperatures than LFP.
This interests me, since it would allow a remote site to have energy storage without heating being required.
An energy storage system mounted in a Truck could be used with little or no heating required during Winter conditions.
There are many applications for energy storage that could benefit from low temperature tolerant cells.
 
OffGridForGood said:
Very interesting - thank you for the contact information Kate.

With LFP cells, I am mostly interested in the Prismatic cells, for building my own "48 volt" (nominal 51.2 volts) battery packs for use with stationary solar energy storage. For my applications I do not need cells that meet the automotive industry requirements, I am happy to have cells that will provide suitable energy density for my solar energy and I like being able to get these lower classification cells for lower cost per cell,
BUT!
Myself, and many of the the forum members here, become concerned about 'what are we getting'. That is to say, I am happy to get "grade B" cells for my solar energy storage for a lower price, but I worry about getting "Grade C or D" but paying Grade B prices.
We have seen EVE are now marking cells with a B on them to indicate the storage grade cells - does your company have plans to also mark the storage grade cells with a marking so consumers know what we are getting for our money?
Click to expand...
Yes, the concerns you mentioned are also worries I face during my everyday shopping. We all hope to pay an equivalent price for products that are worth it. Currently, the majority of our battery cells are being supplied to the Indian market, where distributors and dealers pay different prices for batteries of varying capacities. Taking the example of cylindrical 32700 cells, cell matching is conducted before assembling them into battery packs. Only cells with similar performance are combined to achieve a well-performing battery pack. In the images, you can see 6050-6075, which means the cell's capacity is between 6050mAh and 6075mAh. Cells are grouped in 25mAh increments, and in terms of voltage, each step is 10mV. Thorough grouping is a prerequisite for obtaining a good battery pack. Therefore, experienced battery enthusiasts engage in this step before assembling a DIY battery pack.

In theory, distributors and dealers should know the grade of the batteries they sell. However, if they sell "B" grade cells at an "A" grade price, how can manufacturers intervene? As for marking "B" on batteries to indicate storage-grade cells, we haven't started that yet, but there have been proposals within the group, and we hope to have good news in the future.
1705458646908.png
 
OffGridForGood said:
I live in Canada, where we have lot of cold weather.
The Sodium cells, from what I read, are able to charge and discharge at lower temperatures than LFP.
This interests me, since it would allow a remote site to have energy storage without heating being required.
An energy storage system mounted in a Truck could be used with little or no heating required during Winter conditions.
There are many applications for energy storage that could benefit from low temperature tolerant cells.
Click to expand...

Cold resistance is a progress. I don't know to what extent sodium batteries can achieve. Last time, when I inquired about the price from a supplier, he told me it's 2 RMB per ampere-hour for the battery pack. However, controlling the size is very challenging. But I think this data cannot be considered reliable because I only asked one person, and during the conversation, he did not demonstrate enough confidence. He also did not provide relevant information. I have reasons to believe that he is not familiar with sodium batteries.
 
Battery_Kate said:
Cold resistance is a progress. I don't know to what extent sodium batteries can achieve. Last time, when I inquired about the price from a supplier, he told me it's 2 RMB per ampere-hour for the battery pack. However, controlling the size is very challenging. But I think this data cannot be considered reliable because I only asked one person, and during the conversation, he did not demonstrate enough confidence. He also did not provide relevant information. I have reasons to believe that he is not familiar with sodium batteries.
Click to expand...
I recently ordered two complete Sodium packs, 100Ah each.
One pack is 12v and the other 24v.
I will test these outdoors during our Winter to see how they perform.
The cost per 100Ah was close to the current price for LFP of 100Ah.
These packs have not yet arrived in Canada, but expected soon.

I know the Sodium cells have a wider voltage range than LFP, however my small 12volt and 24volt Inverters will not be able to utilize this full voltage range. I will learn how much capacity is lost, due to the limited range of the small inverters.

For a larger system, in 48volt, there are Inverters that can use the full voltage range of Sodium cells.
I have not yet found a source for just Sodium Cells, only the finished battery packs.
 
OffGridForGood said:
I recently ordered two complete Sodium packs, 100Ah each.
One pack is 12v and the other 24v.
I will test these outdoors during our Winter to see how they perform.
The cost per 100Ah was close to the current price for LFP of 100Ah.
These packs have not yet arrived in Canada, but expected soon.

I know the Sodium cells have a wider voltage range than LFP, however my small 12volt and 24volt Inverters will not be able to utilize this full voltage range. I will learn how much capacity is lost, due to the limited range of the small inverters.

For a larger system, in 48volt, there are Inverters that can use the full voltage range of Sodium cells.
I have not yet found a source for just Sodium Cells, only the finished battery packs.
Click to expand...
Yes sodium batteries don't seem to be much more expensive than LFP batteries. Hopefully you can share more information once the battery pack arrives.
 
Battery_Kate said:
Yes sodium batteries don't seem to be much more expensive than LFP batteries. Hopefully you can share more information once the battery pack arrives.
Click to expand...
I will post my review once I have them and can do some testing.

I expect that Sodium cells will be much lower cost than Lithium if the sales volumes become similar. Sodium is a very abundant mineral, although if all sources can be used in their natural form or not, I don't know.

For stationary ESS, the Sodium can be heavier, and less density than LFP, it doesn't matter very much, as long as they are lower cost/kWh and have similar cycle life. As I said earlier, my main interest initially is the low temperature range for charging and discharging without heating required.
 
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