What's difference among Grade A ,Grade A- and Grade B?
Many customers asked this question and don't know what is the difference among them.
These are are "sticker" that people/seller/manufacturer gave the batteries.
There is no standard or strict regulation for these three stickers.
Now let's narrow down the topic just for the big capacity prismatic lithium ion cells,
and also focus on the several famous brands most customers are dealing with:
First, grade A is 100% new, direct from factory. The factory supply battery modules for electric car manufacturers in a huge quantity.
the grade A single cells are not common in the market. But some companies can get the cells via special relationship.
Some of the cells are available in the market. For volume EV production,we recommend grade A. The warranty normally has 3~5 years.
Second, The battery production is by machine.automatic production line. the First Pass Yield is 95~98%.
2~5% are not so perfect, just a little and not affect usage at all. the raw material and production procedure are the same.
these small part of batteries will be selected out according to the high strict standards.
these grade A- batteries are new and never be used before. they are not able to be matched for above 300V pack.
they are very good for energy storage and low speed EV within 72 V.
These application tends to charge/discharge the batteries at lower current. Maybe 0.1C~1C . (The lower rate,the longer cycle life for the battery)
On one hands, the battery will be able to have a good performance for these area and run 5~8years.
On other hands,the cost is 30%~50% lower than grade A. So it is a wise choice to use the grade A- cells.
They are called "grade B " or "grade A-". or some seller also call them "grade A",we think this is dishonest.
Deligreen will be honest and never give a false "sticker" to any battery.
Most suppliers offer 1 year warranty. Deligreen can prolong 2 years, that is 3 years warranty.
Third, some batteries were installed in electric car or bus. After they are running several years, the batteries will be disload.
these batteries are disassembled and called "grade B".Some of them were never been used before since the EV are never run as well.
Some of them were used for some cycles. It depends.....
After dismantle from EV, the cells appearance will look urgly. but it doesn't mean they are not good cells.
They were the "golden" perfect cells and they were matched by the factory.
Some of them can be still used for several years for energy storage sytem.
but they may be out of balancing if you don't select them and match them.
if you add the Deligreen active battery balancer, it will be quite helpful to improve the situation.
Every coin has two sides. It depends on what's your application, what is your expectation ,and how much you'd like to pay.
You can consider carefully and make the most suitable choice.
Kind reminding: Don't simplely judge the seller :Grade A or grade B.
If you get very low price and the seller said it is grade A, that is likely not true.
You get for what you paid.
If you have different opinion or want to be our dealer,welecome to email us.