Lithium Batteries Explained: Lithium-ion vs Lithium vs Lithium Polymer

All lithium batteries are not the same.

Lithium battery can be used to describe various kinds of lithium technologies, all of which behave differently. Lithium batteries can have different voltages, different specific energy and characteristics and even different reactions when damaged.

When you see the words lithium-ion, it may refer to one of a dozen distinct types, each with its own specific voltage, energy density and safety. More types appear every day because scientists and battery makers are still exploring what’s possible.

One person studying the lithium battery frontier is Dan McMartin, a battery expert overseeing the quality team at Interstate All Battery Center.

He’s often the first to see what’s new in the lithium battery world.

“We are at the beginning of a very exciting time. There is a ton of work being done to foster rapid advancements in lithium cells that are helping to continually evolve the world of lithium,” McMartin said.

McMartin said he typically runs across two common misconceptions about lithium batteries: They’re all the same, and they’re dangerous.

“I’ve been a fan of lithium batteries for countless years,” he said. “I love the benefits and flexibility that come with them, like the ability to charge and discharge more rapidly. I love the fact you can half-charge or partially charge them and yet still experience their full power.”

The truth is they’re all different, and some are safer than others.

RELATED: How to Pick the Best Trolling Motor Battery for Your Boat.

What’s the Difference Between Lithium-ion, Lithium Polymer and Lithium Batteries?

The term lithium by itself usually refers to primary, non-rechargeable batteries. They’re used in watches, smoke detectors, hearing aids, pacemakers, key fobs and other small, relatively low-power electronics. It’s also called lithium metal battery. This category of lithium includes chemistries such as:

• dióxido de manganeso-litio
• lithium thionyl chloride
• lithium poly carbon monofluoride.

The other popular kind is alkaline. These lithium batteries will outperform alkaline batteries because of their energy density. Lithium offers more power per cell than alkaline and can have a longer shelf life than alkaline batteries. Normal shelf life for alkaline is seven years where lithium metal batteries are capable of up to 10 years if you draw a little power from them periodically.

Lithium-ion refers to rechargeable batteries, also called secondary batteries. Lithium polymer is another type of lithium-ion, and it uses a gel instead of a liquid electrolyte. These are common in devices that need more power on demand, such as phones, laptops, jump starters, power tools, electric vehicles, medical instruments, etc. A wide variety fall under the lithium-ion category:

• Lithium nickel manganese cobalt
• Lithium nickel cobalt aluminum
• Lithium iron phosphate
• Lithium cobalt oxide
• Lithium manganese oxide
• Lithium titanate

“Honestly lithium is essentially a generic term. It’s just the identifier or name people use for a broad category of batteries,” McMartin said.

Adding new elements changes the battery. Scientists can raise the battery’s energy density. They can also improve how well it works in extreme temperatures.

Most importantly, they can increase its safety.

One of the most popular lithium batteries in phones and tablets is lithium cobalt oxide. While it delivers lots of power on demand, it also can be volatile if punctured, McMartin said. Other dangers include trying to charge lithium below freezing temperatures. Doing so can create lithium dendrites, a thin needle of lithium that punches through the separator layer and short circuits the battery.

That’s one of the reasons why battery manufacturers equip lithium batteries with battery management systems. These circuits watch the safety and performance of the battery pack.

“These are smart batteries. It’s not just a box of volts and amps,” McMartin said. “Now we basically have a computer sitting on top of a battery telling that battery pack what to do.”

Battery management systems will cut off the connection in a microsecond if it detects a short circuit, temperatures that are too cold or too hot or even if it is subject to improper voltage or current. That system makes lithium batteries safer to handle in general.

One other condition that affects the safety level of certain types of lithium batteries is dependent upon how tight of a bond is formed between the oxygen molecules and its other elements within the active material if the cell was to experience a thermal event.

The most common lithium-ion battery type is lithium nickel manganese cobalt. The cobalt has a weak bond to the oxygen. That makes it a potential hazard. Scientists can use other elements instead of cobalt to make safer batteries. One of the safest is lithium iron phosphate.

“The bond between the phosphate and oxygen molecules is very tight making it an extremely stable type of lithium cell,” he said. “You would need to exceed 500 F to get them to separate. In that sense, it’s a much safer product.”

That’s one of the other reasons why Interstate Batteries experts chose lithium iron phosphate for its golf and marine/RV batteries.

Power Beyond Compare^™: Benefits of Lithium Iron Phosphate Powering Marine, RV and Golf Batteries

Trolling motors, campground cookouts and neighborhood trips are about to get more powerful, to feel a whole lot lighter and run a whole lot longer — thanks to the new lithium batteries from Interstate Batteries.

The lithium batteries change the game for deep-cycle batteries. It’s the power of lithium iron phosphate batteries (also known as LiFePO4) with terminals and voltages compatible with boats, RVs and golf carts.

Energy density is lithium’s biggest advantage. It delivers more amps per pound of battery than other deep-cycle batteries. On average, lithium batteries weigh a fourth of what a lead-acid battery weighs while delivering just as much amperage and much longer lifespan.

That energy density pays off for boat owners with the lithium marine battery from Interstate, especially for competitive fishers.

The lithium marine batteries come 12-volt, 24-volt and 36-volt sizes, meaning anglers can replace a bank of three or four deep-cycle batteries with one 36-volt lithium marine that weighs less and lasts longer.

“Say I need to get from spot A to spot B quickly,” said J.D. Felts, senior product manager for Interstate Batteries. “With these, I can reduce the cargo weight by 200 to 300 pounds. Even if it shaves 20 seconds off my time, that’s more time, and pros are looking for any edge they can get on the water.”

Felts is one of the leaders guiding the development of Interstate lithium batteries, working side-by-side with McMartin. He’s been part of the Interstate Batteries legacy for more than a decade, combining a love of the outdoors with battery expertise. For him, the peace of mind from our batteries is one of the biggest benefits.

The lightweight 12-volt lithium battery lightens the mental load for RV owner, too. Most motor homes and travel trailers use marine/RV batteries for house loads, powering cooking, lighting and electronics. That said, RV owners spend plenty of time calculating tow weight to see how much they can bring before their gets too heavy. Hundreds of pounds of lead-acid batteries could be replaced by a couple of lithium batteries. That means RV owners can either get better gas mileage or bring more of the comforts of home to the great outdoors.

The biggest benefit may be their long run-time.

Having more juice per charge helps whether it’s a travel trailer, trolling motor or even golf cart.

“You can get longer run times, more miles per charge. Golf course managers think about how many rounds of golf can I get out of this before it needs to sit and recharge,” Felts said. “Most course managers expect to get two full rounds of golf before they have to recharge for eight hours. These recharge up to three times as fast. That means you don’t need to have 50 carts down for eight to 10 hours a day.”

That’s a lot more playing golf, and a lot less time playing with golf cart cables.

The most important benefit of lithium batteries is what Felts and McMartin called a flat discharge rate.

Think about how your smartphone battery works. You can drain a phone to 50%, and the phone won’t act differently than when it was at 100%. The processor won’t slow down. The touch screen won’t lag even if its battery is at 50%. That’s a flat discharge rate.

Lead-acid batteries do give noticeably less power if they’re less than 75% charged.

“If I don’t have a charge in a lead-acid battery, the discharge curve drops off like a waterfall really quickly,” McMartin said. “If I put it in a trolling motor and I’m running it all day long, that motor’s going to start bogging down. You don’t get that with lithium.”

That means you can drain your lithium trolling motor battery or golf cart battery, recharge it in an hour and still enjoy a full day of play without worrying.

On top of that, the lithium marine and golf cart batteries recharge faster than lead-acid batteries. With the right charger, they can get back to 100% in just one hour.

The lithium iron phosphate batteries also feature a long lifespan. Felts said it’s possible these new lithium batteries could last five to 10 years longer if handled well. McMartin offered a couple of important tips for getting the most out of your lithium battery:

• Keep it charged between 30% to 80%.
• Only use the right battery charger.

RELATED: How to Pick the Best Trolling Motor Battery for Your Boat.

How Do You Recharge Interstate Lithium Batteries?

Use a battery charger with a lithium charging profile, such as the PS Series charger from PRO Charging Systems, when recharging the new lithium batteries from Interstate. McMartin recommends a charger with a lithium setting or one labeled for lithium batteries. Look for a setting marked “Li.”

Do not use a charger meant only for 12-volt, lead-acid batteries. Lithium and lead-acid batteries need to be charged in completely different ways. Lead-acid batteries prefer a low, slow charge, but lithium can take more current all at once. Instead of only accepting one-tenth of its capacity in an hour like lead-acid batteries, the lithium batteries can take their full capacity in an hour.

Additionally, the battery management system on each lithium battery also makes recharging safer. For instance, lithium batteries do not like trickle charging. When a lithium battery hits 100% charge, its onboard battery management system refuses anymore power. If the charging voltage or amperage aren’t quite right, the system refuses power. That protects you and the battery, too.

In turn, that protection also keeps your RV’s alternator from hurting the lithium RV battery, said Jeff Barron, Interstate Batteries automotive electronics expert. Even though it’s designed to offer some power to typical, 12-volt lead-acid batteries, your alternator is not a battery charger.

Bus Bar, the Unsung Accessory of Interstate Lithium Iron Phosphate Batteries

If you own a boat or RV, there is one other accessory LiFePO4 battery owners should consider picking up: bus bars.

Bus bars are thin metal rods that do the job of battery cables with better conductivity and cleaner, more secure connections. The rod has two holes for battery posts. Securing two or three batteries with bus bars makes a sturdier bank of batteries.

Because rods are thicker than most cables, the energy transmission is more efficient. Thin-gauge cables and alligator clips can heat up as you draw amps, turning electricity to heat instead of what you need. So, if you’re running a trolling motor or cookout, your batteries may not last as long.

Bus bars are thick enough to bear more amps. That’s especially important when working with a bank of lithium iron phosphate batteries. LiFePO4 batteries can give and take high-amp loads. To get the most out of them, you need connections designed to bear that load.

McMartin said their team designed their bus bar for better conductivity than others that use aluminum. Interstate Batteries bus bars use copper with nickel plating. Copper acts as a better conductor while the nickel protects it from the environment, such as corrosive salt air.

Bus bars also solve a problem affecting most battery bank set-ups: Imbalanced cables. Cables have their own issues of internal resistance, taking more space around the batteries, and poor energy transfer draining the batteries. If you use cables of different lengths to connect batteries in series, that imbalance will add new problems. If one cable’s much longer than the other, you’re effectively cutting how much power you can get from the battery bank. Bus bars come in fixed lengths for a secure, balanced connection.

What’s the Future of Lithium Batteries?

With new technology emerging every year, what’s next?

“You’ve probably heard about it. The biggest and most popular one that people know about is solid state,” McMartin said. “They have trouble mass producing it. Some companies say they’ve cracked the code, but I’ve not seen the product on the market.”

Solid state batteries get their name because, unlike all other batteries, they have almost no separation between both polarities. Lead-acid batteries, lithium-ion batteries and even alkaline batteries have a third material between the anode and cathode. Solid state batteries would only have a layer of material nanometers thick that ions could jump freely through. However, that technology to make that isn’t yet available.

McMartin has also seen powerful possibilities from lithium sulfur to lithium aluminum to sodium-ion batteries. He’s seen teams developing alternatives. The aim behind each innovation is finding a battery that’s safer and lasts longer.

Possibilities are as powerful as lightning.

And it takes a powerful brand like Interstate Batteries to catch it in a bottle. Or a battery.