Under normal circumstances, protection-free storage batteries can also be used for compensation charging, and the charging method is basically the same as that of ordinary storage batteries.
When charging, the voltage of each cell should be limited to 2.3-2.4V. Note that charging with conventional charging methods will consume more water, and the charging current should be slightly smaller (below 5A) during charging. Fast charging is not allowed, otherwise, the battery may explode and cause injury. When the hydrometer without protection battery appears light yellow or red, it means that the battery is nearly obsolete. Even if it is recharged, the service life will not be long. Charging at this time can only be used as an emergency measure.
