The core reason why lead-acid and lithium batteries are "incompatible" is not that they can both discharge, but rather that their three major systems—voltage, chemistry, and protection—are completely different. Mixing them equals instantaneous damage and safety risks. I. Different Voltage Systems ItemLead-acid (12V example) Lithium-ion (12V example) Single Cell Full Voltage 14.4 V 16.8 V Open Voltage 12.8 V 12.6 V Cutoff Voltage 10.5 V 8.4 VResults of Mixing: Using lead-acid at 14.4V to charge lithium battery → will never fully charge, capacity decreases by 30%;Using lithium-ion at 16.8V to charge lead-acid → overcharge, water loss, bulging, lifespan halved. II. Different Chemical Systems Lead-acid: Three stages (constant current-constant voltage-trickle flow), trickle flow 2-4 hours, desulfurization; Lithium-ion: Two stages (...

Not universal   Lithium battery chargers and lead-acid battery chargers are not universal.   Lithium batteries and lead-acid batteries are different types of batteries, and their charging principles differ. Lithium batteries are charged using constant voltage, while lead-acid batteries are charged using constant current. Lithium battery chargers use a constant current-constant voltage (CC-CV) charging mode, while lead-acid battery chargers mostly use a constant voltage or staged constant current charging method. Furthermore, the voltage levels of lithium batteries and lead-acid batteries are not compatible. Using a lead-acid battery charger to charge a lithium battery can cause bulging, deformation, and even explosion. Using a lithium battery charger to charge a lead-acid battery makes it difficult to fully charge the lead-acid battery. Over time, the lead-acid bat...