Can i charge a lithium battery with a normal charger

As the process of replacing lead-acid batteries with lithium batteries is accelerating, some people have switched to lithium-ion battery electric vehicles after buying lead-acid battery electric vehicles.So can i charge a lithium battery with a normal charger ? In most cases, the answer is NO.

Related Article《Which is more better for electric vehicles, lead-acid batteries or lithium batteries?》 

Since lead-acid battery chargers are generally set to two-stage or three-stage charging mode, the voltage levels of lithium batteries and lead-acid batteries do not match. There are many kinds of lithium batteries, and the battery performance and battery protection board parameters may be different. Therefore, lithium batteries do not have universal battery chargers like lead-acid batteries. Generally speaking, lithium batteries are equipped with special chargers when they leave the factory. In order to protect the lithium battery, a special charger is required.

In fact, in order to overcome the large internal resistance of lead-acid, the lead-acid battery charger increases the charging voltage by about 5% during constant current charging, which means that you choose the same voltage charger to supply power to the lithium-ion battery. The voltage will be higher, because the internal resistance of lead-acid is large, in order to achieve the efficiency of constant current charging, the constant voltage voltage is increased during the constant current, which is very unfavorable for the lithium-ion battery.

Furthermore, many lead acid chargers have desulphation and equalisation stages built in, which will pulse high voltages of 15.3-15.8V into the battery. This is really important to correctly charge and to maintain lead acid batteries, to avoid stratification of the electrolyte and ensure proper voltage equalisation of the cells, but are definitely not suitable for LiFePO4 batteries. It can heavily reduce the life of the cells due to regular over voltage charging or cause irreversible damage to the battery.

Many lead acid chargers have equalization as an automatic stage that cannot be turned off.  When these stages kick in, they will cause pretty much every good quality LiFePO4 battery on the market with an internal BMS to go into high voltage disconnect protection mode at around 15.0V – the battery goes open circuit and the charger and all loads disconnect before starting all over again once it resets (if it auto resets – not all BMS will do this automatically).  For those that don’t, the battery is open circuit and turned off till you realised and take action to reset it.  For those that do, you then get an on/off/on/off scenario for many hours leading to poor charge performance and sometimes never getting out of those stages for many hours.

In conclusion, standard battery chargers cannot provide the continuous voltage and current required by Li-Ion batteries. If you ask for and expect the best Lithium batteries, your best bet is to use a charger made specifically for Lithium batteries.