Why Lithium Batteries | ROCKSOLARS

Why Lithium Portable Power Station?

These batteries are referred to as rechargeable deep cycle batteries are used in most solar power systems setups. However, the new Lithium battery is becoming the battery of choice for many reasons and it is also why we have a biased towards Lithium battery power stations:

Lighter weight.

When it comes to weight, the Lithium battery wins hands down. It is typically half to one third lighter than the original lead acid battery weight (for an equivalent run time/capacity lead acid battery bank).

Higher electrical efficiency.

The Lithium battery has a much higher electrical efficiency compared with lead acid batteries. LiFeTech lithium batteries are typically 98% charge efficient compared to between 70% and 85% with the lead acid batteries. They also have significantly faster charging times than lead acid batteries.

What this means is the Lithium battery will charge more efficiently and more quickly than a lead acid battery. This can be particularly important in situations with limited charging methods available, such as from solar panels.
For example, camper van owners have reported that their LiFePO4 batteries are fully charged from solar panels by midday compared to 4 to 5pm using their old lead acid batteries.

Longer working life.

While good quality Lithium batteries such as C&C Power Supply batteries are far more expensive to buy and set up initially, the actual cost of ownership is considerably cheaper than lead acid batteries (calculated in terms of cents per charge cycle).

Constant Voltage.

In a lead acid battery, voltage will continue to drop over time as the internal circuit within the battery will self discharge. This forces the connected electrical device to eventually shut down at its minimum operating voltage. In the Lithium battery, however, voltage tends not to drop under load until the battery is almost depleted.

For example, an ignition coil in a motor vehicle will have a consistent spark due to the battery’s ability to delivery a consistent voltage. This means electrical equipment tends to run more efficiently as they are receiving constant voltage. Ultimately, using Lithium batteries gives electronic equipment a longer working life before failure than the lead acid battery option.

Faster recharge.

Expect to spend much less time recharging Lithium batteries than lead acid batteries.


Lithium batteries are the safest batteries for consumers and the environment. Internally, they do not contain corrosive sulfuric acid or any toxic heavy metals such as lead or cadmium which can be environmentally harmful if leaked.

Lithium ion (NMC) vs LiFe PO4.

While a single cell LiFe PO4 has a 20-30% longer life cycle than Lithium ion (NMC), there are a number of reasons that ROCKSOLAR had chosen Lithium ion batteries for our portable power stations.

LiFe PO4 has lower energy density than Lithium ion (NMC), so it is 30% heavier and 40% bigger which is not ideal for portability. In fact, when the batteries are packed together, the life cycle of LiFe PO4 and Lithium ion (NMC) battery packs are about the same.

With lower power density, the LiFe PO4 is a cheaper battery but is more suitable for big, heavy, stationary generators and are not suited to portable products. This is why you won’t see LiFe PO4 batteries used in Tesla cars, or in our current line of ROCKSOLAR products.