Use of lead-acid batteries is widespread globally because they are relatively inexpensive to produce.
These batteries are reliable and can withstand harsh conditions with little or no maintenance.
Although people view the materials inside as dangerous, the battery is almost 100 percent recyclable. Sulfuric acid is safely neutralizable, and the lead and polypropylene case can make other batteries.
Traveling with a device that utilizes a lead-acid battery is far less complicated.
Very affordable - a Group 31 size deep cycle lead-acid battery with 100ah of capacity will cost $150 - $300, depending on type and quality.
The batteries are too heavy and bulky for a given capacity.
Lack of proper recycling of the materials could be hazardous to the environment.
They have a limited lifespan.
Spillable lead acid batteries are classified as dangerous goods under Class 8 regulations, controlled by UN 2794. This is because of the risk of fire if shorted.
Shorter lifespan and cycle life than LiFePO4 batteries, especially when they're deeply discharged.
Discharging deep-cycle lead-acid batteries below 20% (and sometimes 50%) permanently reduces the battery's capacity.
High current loads rapidly diminish rated capacity...most deep-cycle lead acid batteries are designed for slow, steady discharge over a 20+ hour period. if the time frame is reduced, the capacity rating drops.
Lithium Iron Phosphate:
Long life span (5-10 years) vs lead acid (1-3 years), depending on depth of discharge and assuming that the cycle limit doesn't kill the battery first
Longer cycle life, as LiFePO4 batteries last 1,000 to 3,000 charge and discharge cycles, compared to similarly sized lead-acid batteries, which can range from 200 - 1000 cycles (again, assuming depth of discharge is within recommended limits for both battery types).
LiFePO4 batteries are less susceptible to problems caused by depth of discharge...a LiFePO4 battery can be dropped to 20% of charge without long-term damage. Most lead-acid batteries lose capacity or cycle life if they're discharged more than 50%.
Lighter than lead-acid batteries.
Arguably, LiFePO4 batteries are more environmentally friendly than lead acid.
Very safe - the odds of a "thermal runaway" (aka battery fire) are very low. The same can not be said of other lithium ion chemistries.
As mentioned, LiFePO4 batteries are costly.
LiFePO4 batteries are hard to find. Most must be purchased online.
Susceptible to damage via overcharging (it's very important to use a charging system that's designed for LiFePO4 batteries if you want to maximize their life).