It's only been two years since the battery dropped from 90 to 40 milesLithium batteriesBut it's not as durable as it used to be. This paradox is shared by many people riding electric cars。
There's nothing wrong with 15 batteries
The 15 cells were tested each time using a spare watch, and the voltage was mostly between 12. 1 and 12. 13 volts, with very small variations, and it can be judged that none of the batteries is bad. On the basis of the voltage performance of each cell, it is true that the battery does not have a significant failure point and that it does not appear to have problems。
However, the owner said he could run about 90 kilometres and could not ride 40 kilometres. The fact that the battery is not broken, the voltage is normal and the water is reduced by more than half, suggests that the problem is not that a single battery has been damaged, but rather that the entire battery's capacity has been reduced as a whole, with each battery actually holding much less electricity than the new battery。
Lead-acid batteriesTwo years of decline is normal
The design life of lead-acid batteries is typically two to three years, and it is perfectly normal to experience a marked decline in capacity on a two-year ride. The polar plate inside the battery is gradually sulphideed, and the active material continues to lose its capacity from 100 per cent to 60 or 50 per cent of its full capacity, and the continuation of the voyage is automatically cut off without any specific malfunction。
The car used 60 volts of lead-acid batteries, with 15 batteries connected to power. The amount of electricity that can be stored in each cell for two years may be about 60%, and the total amount of electricity released from the whole group is significantly reduced, falling from 90 to 40 kilometres, which is entirely within a reasonable range of decay, and is not a mass problem for the battery itself。
Intra-battery contrast experiment
In order to see directly why old batteries could not travel far, a new set of batteries was deliberately compared. Each of the old and new batteries will be connected to 60 volts, filled with two of the same chargers at the same time, pulled down for half an hour, removed all the links, and measured the internal resistance of each battery on a block-by-block basis with an internal resistance test。
The internal resistance of old batteries has been detected in the range of 17 to 18 om, and new batteries in the range of 11 to 12 om. The greater the internal resistance, the better the small battery, the greater the internal resistance of the old battery, the fact that an irreversible ageing reaction has taken place internally, the increased energy loss when charged, and the lower amount of electricity actually stored in the battery are the main reasons why it cannot go far。
Capacity discharge measurements
The constant discharge test was performed using a capacity detector, and the 20-ion currents placed two pieces of each of the old and new batteries. After about 40 minutes, all batteries were placed at the cut-off voltage. Only 13. 8 and 12. 7 entanglements of the old batteries were measured, respectively, for severe decay, with a significant deviation from the nominal 20。
The new batteries detected 15. 9 and 15. 6, respectively, and did not meet the nominal 20. Because of the different brands of old and new batteries and different batches of production, this data set does not represent absolute precision for reference purposes only. If small currents were replaced with 10 entries, the capacity figures would look better, but the actual cycling battery capacity did continue to decline。
How long will the new lithium battery last
The owner spent more than 2000 on a group of 60 volts of lithium batteries with theoretical circulation life ranging from 800 to 1,000 times, and normal use of three to five years of continuous decay would be relatively small. The decision to change the battery is not a problem compared to the two-year-old lead-acid battery, which does have a level of durability。
But lithium batteries can't be built on it. These habits accelerate the decline of capacity by charging it immediately after summer sunbaths, charging it fast in cold winters and often riding it to the bottom. After two or three years of use, there is a marked reduction in the continuation of lithium batteries, not once and for all。
Changing batteries doesn't mean getting a new car back
Many car owners feel that new batteries can restore their experience when they first buy them, but not. The control parameters, electrical efficiency, tyre air pressure, friction resistance at the joints of the frame remained unchanged, the battery capacity was larger, and the actual flight could be reduced if the tyre had insufficient air pressure or if the electrical power had decreased。
After the battery is replaced, it is recommended that the voltage and current parameters of the controller be calibrated, that the match between the electric and the transfer be checked, and that the four tyres be hit to a standard value. When these details are in place, the real continuation of the new battery will be fully activated, otherwise the actual experience will be less than a thousand dollars in exchange for the battery。
It's yoursElectric car batteriesHow long will it take for you to clearly feel like you can't get far? Do you want to keep working on it or do you want to switch a lithium battery? The comment section talks about your experience, and if it's useful, just order a compliment and forward it to your friend on the bike。
