CHARGING LITHIUM BATTERIES WITH A LEAD ACID CHARGER
**Important note ** Using a non-lithium compatible charger on AMPTRON LiFePO4 batteries will void your warranty.
We do not recommend the use of any charger that is not lithium profiled or compatible.
Please see below for an explanation of the differences between a Lead Acid profiled charger vs a charger that has a Lithium specific profile, and what the implications are:
- A Lithium charge profile vs a Lead Acid profile usually has a slightly higher charge voltage and a “deeper” constant voltage phase at the end of the charge cycle. This profile gives Lithium batteries a full 100% state of charge. A Lead Acid charge profile will not normally achieve the same outcome however, depending on the charger brand and type, some chargers can achieve an approximate 95% state of charge which is not ideal for achieving an extended life cycle of the battery’s internal cells.
- Comparing LiFePO4 lithium & lead acid battery chargers the charge profiles have a different “return to boost” behavior. After the charger completes its full charge cycle (i.e. it reaches the end of the absorption phase and changes over to the float stage), the charger will then start to monitor the battery voltage, to decide when to switch back to the boost/bulk charge mode and restart a full charge cycle again. The issue is that Lead Acid chargers will wait for the voltage to drop too low before it restarts the charge cycle – the reason for this is a Lead Acid battery has a lower resting voltage compared to a Lithium battery. The implications are that the Lithium batteries’ State of Charge may already be quite low before the Lead Acid charger decides to switch back into a full bulk charge where a Lithium profiled charger will start to recharge the battery much sooner.
- A Lead Acid charge profile will enter a float stage at the end of the charge cycle. This is designed to trickle charge lead acid batteries to compensate for self-discharge, and any excess energy is dissipated as heat. LiFePO4 lithium batteries have a very low self-discharge rate ultimately removing the need for float charging. The issue is that when float charging LiFePO4 lithium batteries, especially if the voltage is above the resting voltage of the LiFePO4 cells, the electrode is likely to produce pure Lithium out of the Lithium ions which causes metallic plating and reduce the cell capacity over time. This will have an adverse endurance effect on the lifespan of a LiFePO4 lithium battery.
Based on the technical details between the lead acid & LiFePO4 lithium charging profiles we only recommend the use of lithium compatible chargers for AMPTRON LiFePO4 lithium batteries and using a lead acid battery charger will void the batteries warranty.