Getting the Best Out of Your LiPo Batteries.
LiPo batteries are just plain awesome. With a rich energy density that equates to extended run times & epic levels of power, LiPo batteries make our hobby great. And since LiPo batteries are absolutely critical in every respect when it comes to our RC applications, it makes perfect sense to take care of these batteries in order to maximize the performance & cycle life LiPo batteries have to offer.
Even though LiPo batteries have dropped in price by a very large margin over the passing years, these batteries are still an investment - especially when it comes to larger packs for bigger RC applications. So, when it comes to maximizing cycle life and overall performance, here's some tips we want to share with you, because we want to make sure your LiPo experience is an epic one.
Purchase Quality Batteries
As the old adage states, "you get what you pay for", and this certainly applies to LiPo batteries. You can find some massively cheap LiPo batteries out there, and that's what you'll more than likely end up with - a cheap battery. You may have saved a few bucks, and we don't blame you for that, as everyone around likes to save cash. However, if you expect some awesome power coupled with a long cycle life, prepare to be properly disappointed, as that likely won't be happening.
As obvious as it sounds, investing in a high quality brand of LiPo battery is worth the extra cost. Reputable brands of batteries have a proven track record, and are often paired with a good warranty plan, combined with someone in customer service who is actually motivated to help you out of your battery has an issue. And in the modern computer age, it doesn't take much effort to easily review brands and see other users and the experiences they're having, making your choice of a LiPo an easy one when it comes to being informed.
In short, pay the few extra bucks up front. You will end up with a pack that lasts longer, performs better, and overall provides you with a much more rewarding RC experience. Save the cheap packs for people who just don't know better - it's not worth your time, and even more, it's not worth the money you think you'll be saving.
Check Your New Packs
One thing we see quite often are customers who receive their battery in the mail, and instantly set them aside for five months without ever bothering to even check their packs out. We've been there before, and that is the way this hobby works at times, as some RC projects don't get moving fast enough, or the weather is just too lousy to get out and fly. However, don't be that guy (or girl, for that matter), as this can lead to trouble.
Considering most LiPo batteries have a specified warranty time that is based on time and not time of use, if you encounter an issue with your LiPo battery that has been sitting on the shelf for the last 7 months, I doubt you're going to fond much leeway with warranty support. And if your warranty request is turned down due to the extended time that has passed, chewing out & threatening the rep you are speaking with won't endear your cause in the slightest, so we don't recommend that path either.
When you receive your new packs, be sure to give them a good overall check. The most important will be voltage: make sure the voltages of the cells look good in terms of individual voltage, which should be around 3.7V per cell. A cell checker is a fast and easy way to determine this. All cells should be very closely matched, so if you see one or more cells with a voltage that is much lower, this could be an issue. Also, check the battery for any type of swelling or deformation, which is a sure sign of battery fault.
If all the voltages look good & balanced and the battery shows no signs of swelling or deformation, you're good to go. You can set the pack aside for later use, or you can begin using the pack right away.
Cycling New LiPo Batteries
Before you push the edge of performance with your new pack, some gentle break in cycles are not a bad idea to help maximize the lifespan of your brand new pack. This will get your battery up to speed and help extend the lifespan of the battery, all the while making sure you reap the greatest gains of performance.
The best way to do this is a 1C charge rate to get your pack up to charge. Not sure how to determine this? Check out our "How To Choose A LiPo Battery For Your RC Needs" blog for some great info on how to determine charge rates for your battery, as this is crucial for battery care and safety. With a 1C charge rate, this will charge your battery at a gentle rate, allowing less overall stress when compared to more rapid charge rates that certain brands of LiPo batteries offer.
Along with a 1C charge rate, we suggest a few gentle uses of the battery without pushing the battery to its maximum 80% discharge - more on that below. Simply put, you don't want to fly with maximum power levels for the 1st few flights, and you want to land early without depleting the battery too far. Once the battery completely cools, charge at 1C and do it a few more times, with (5) cycles being plenty to get your battery in optimum shape for full power runs.
When it comes to extracting the maximum cycle life & performance out of your LiPo battery, charging is crucial. From proper settings, amperage rates, balance charging and more, you want to make sure your battery is properly cared for when charging, as this will help extend the cycle life of your LiPo packs.
Just put in a really hot flight? Check your battery - it's probably a bit hot as well due to the amount of amperage being pulled out of the pack in such short order. Before you decide to charge the pack and go for round 2, let the pack cool to ambient temperature, as charging a warm / hot LiPo battery will wear the pack out much faster. Even further, if your battery is hot to the touch after flight, this is indicative that your pack is working a bit too hard to keep up with your flying style and / or the power system you have in place. In a case like this, a higher C rating pack is recommended, as maxing out your battery every flight will lead to shorter cycle life.
When charging your battery, your LiPo charger is more than likely balancing your pack as well. However, most chargers will have a more thorough balance option, which usually takes a bit longer to charge the battery. If your charger has this option, use it from time to time to allow all the cells of your battery to be fully and equally balanced.
Like parallel charging? We don't. Parallel charging will allow you to charge multiple batteries at once to keep you on the go when it comes to using your LiPo packs, but you're playing with fire - quite literally. Since your charger cannot properly "see" all the cell voltages with a parallel setup, if the batteries being charged are out of step with each other voltage wise, the likelihood of overcharging a pack is very high, and very easy indeed. You can end up destroying your batteries in short order, or worse yet, your packs could catch on fire from over charging. Simply put, it's a bad idea, and despite the multiple parallel charging options available, we do not recommend it in the slightest.
This is a big one. Although "most" RC guys & gals know this as a cardinal rule, we still see many people that charge their packs, only to let them sit without use. Simply put, LiPo batteries hate this. If you charge your LiPo battery up, use it. Letting the battery site for days & weeks at full charge places undue stress on the cells, and after a period of time, this harms the battery. It's also a greater fire risk for a LiPo to be fully charged and doing nothing, which is yet another good reason to not leave a battery peaked out and sitting pretty.
There are plenty of variables out there when it comes to "how long" LiPo batteries can be safely stored at full charge. Personally, anything beyond (1) week is too much, so if you have a fully charged battery that you don't plan on using for more than a week, it's a great time to place the battery in a storage charge.
Every modern LiPo battery has a storage charge function, and it's a very basic task. In short, the charger will either charge or discharge the battery to a voltage of 3.7V - 3.85V per cell (depending upon the charger), which is a LiPo battery's "happy place" when it comes to proper LiPo care. If you have a fully charged LiPo that needs to be placed in a storage charge, it's best to deplete the voltage the fun way - i.e., flying or driving, as the majority of LiPo battery chargers can only discharge a battery at a very low amperage rate, equating to ages on the charger.
80 / 20 Rule
The 80 / 20 rule is very simple, yet very crucial. Simply put, never discharge more that 80% of the mAh from your LiPo battery, always leaving at least 20% of the mAh in the pack. So, if you have a 1000mAh pack, the maximum you should ever deplete from the pack is 800mAh, and the maximum mAh that you put back in the pack during the charge phase should be 800mAh or less. Anymore means you have over discharged the pack, equating to the possibility of hurting the battery or damaging it for good.
With any type of RC application out there (sky or surface), the ESC should be programmed with an LVC - Low Voltage Cutoff. This is a setting programmed within your ESC to cut power when the ESC senses the battery is very close to being depleted below a critical threshold, thus preventing the battery from being damaged while in use. However, the LVC can still be pushed, and you never want to fully depend upon your LVC - especially for aircraft, as an LVC cutoff equates to a very quick landing process, which may end quite badly if not prepared.
In short, you always want to make sure your batteries are not being over discharged while in flight. After your batteries have cooled, the voltages should be 3.7V per cell or greater, indicating that the loaded voltage while in use didn't pull them below 3V per cell. This will keep your batteries safe, happy and able to keep providing cycles down the road. If the 80/20 rule is ignored or not respected, prepare to end up with batteries that puff, lack performance or flat out die - not an ideal option, to say the least.
Storing Your Batteries
Done for the season, or just plan on putting your batteries away for a few weeks? Once you have storage charged your batteries, store them in a cool, dry place, with an optimal temperature around 70 degrees, as this is a LiPo battery "happy place" that will keep your packs going strong for the duration.
Since LiPo batteries dislike heat, storing them in a very hot climate exposed to high temperature extremes can critically harm the batteries and compromise their life altogether. Lower temps aren't ideal either, but it's the high temps that cause true stress. So, it's best to store your packs in a cool locale that will protect them, as high temps are just a bad deal all around.
And even though it has been said many times via our battery safety blog, do not store your LiPo batteries in your house, garage, or any area that has combustible materials close by. LiPo battery fires are rare, but they do happen, and for those that ignore this crucial warning, they end up losing in a HUGE way. Invest in some simple & easy LiPo safety gear like the BAT-SAFE, allowing you to store your LiPo batteries safely - especially if the worst case scenario arises.