SLA Batteries v Lithium Batteries

Lead-Acid batteries have been around for some 150 years as the first type of rechargeable battery and while there are several varieties, they continue to be the most popular type of rechargeable battery for a variety of devices and they are durable, inexpensive and proven. Lithium batteries are a much more recent addition, dating back to the 1970’s but it really gained popularity with significant performance improvements through the late 1990’s and early 2000’s. It continues to gain momentum.

There are a few types of lithium batteries which are mostly dictated by their chemical compositions. The most common is Lithium Iron Phosphate (LiFeP04) predominately due to its stability but also high current, long cycle life and hardiness; they won’t overheat and can handle a decent amount of abuse and environmental extremes.

Lithium batteries do require closer monitoring so having a Battery Management System (BMS) is important as the cells can be impacted from over or under current, over or under voltage or over under temperatures, all of which can cause permanent damage.

Differences Between Lithium-Ion and SLA Batteries

More often than not, comparing Lead Acid batteries and Lithium-Ion batteries depends on your purpose. Will you be replacing an existing SLA or Lithium battery? What temperatures will the battery be subject to? What’s your budget? What equipment will it be for? If you’re looking for a battery to start an RV you’ll probably be choosing a different type of battery versus one for an electric scooter. These are all good things to keep in mind. 

Both are versatile and can be installed in any direction, both lithium and SLA batteries will not leak like Lead Acid batteries which allows both to be placed in any direction.

Weather has an impact on both types of batteries. Charging Lithium batteries at temperatures below freezing can be very challenging and some won’t charge and all. In addition, charging in freezing temperatures can cause plating which, when sufficiently built up can actually cause a short in the cells and result in mechanical failure so allowing the charge rate is highly recommended. SLA Batteries are a little more resilient when it comes to cold weather charging though performance in cold weather sees Lithium batteries slightly ahead.

SLA  batteries have been around for a long time. Many people feel comfortable knowing that they will most likely just work. Lithium batteries are a newer option in the battery space and there may be some question marks over their long-term viability.

Lithium batteries are usually lighter than lead acid batteries, they pack more energy into smaller space though they can be susceptible to heat reactions from dropping or overcharging and can result in fires and toxic fumes. Both SLA and lithium can be damaged, the SLA battery is a little more resilient.

Lithium batteries will last longer than an SLA battery and are not impacted by partial charges. Some claim they’ll last 2-3 times longer than an SLA battery though this often depends on the care and conditions.

Lithium batteries usually charge faster than lead acid batteries.

Lithium batteries can be more difficult to find than lead acid batteries which can be readily found in automotive stores and big box dealers like Walmart or Target. 

Both Sealed Lead Acid batteries and Lithium-ion batteries are maintenance free. No need to fill water chambers or add chemicals with either.

So as it turns out, both SLA and Lithium batteries have their own pros and cons so it really depends on where your priorities are. SLA is often an easier option – lower upfront costs, you can find an exact replacement, and is more of a known entity. Lithium batteries - more cost upfront but will last longer. There may be some additional considerations if switching from SLA to lithium like charge controllers, cranking amps, alternator performance which are all worth taking into consideration when researching your options.