When buying a new battery I suggest you purchase a battery with the greatest reserve capacity or amp hour rating possible. Of course the physical size, cable hook up, and terminal type must be a consideration. You may want to consider a Gel Cell or an Absorbed Glass Mat (AGM)

Be sure to purchase the correct type of battery for the job it must do. Remember that engine starting batteries and deep cycle batteries are different. Freshness of a new battery is very important. The longer a battery sits and is not re-charged the more damaging sulfation build up there may be on the plates. Most batteries have a date of manufacture code on them. The month is indicated by a letter 'A' being January and a number '4' being 2004. C4 would tell us the battery was manufactured in March 2004. Remember the fresher the better. The letter "i" is not used because it can be confused with #1.

Battery warranties

Battery warranties are figured in the favor of battery manufactures. Let's say you buy a 60-month warranty battery and it lives 41 months. The warranty is pro-rated so when taking the months used against the full retail price of the battery you end up paying about the same money as if you purchased the battery at the sale price. This makes the manufacturer happy. What makes me happy is to exceed the warranty. Let me assure you it can be done.

Battery life and performance

Average battery life has become shorter as energy requirements have increased. Two phrases I hear most often are "my battery won't take a charge, and my battery won't hold a charge". Only 30% of batteries sold today reach the 48-month mark. In fact 80% of all battery failure is related to sulfation build-up. This build up occurs when the sulfur molecules in the electrolyte (battery acid) become so deeply discharged that they begin to coat the battery's lead plates. Before long the plates become so coated that the battery dies. The causes of sulfation are numerous. Let me list some for you.

Batteries sit too long between charges. As little as 24 hours in hot weather and several days in cooler weather.

Battery is stored without some type of energy input.

"Deep cycling" an engine starting battery. Remember these batteries can't stand deep discharge.

Undercharging of a battery to only 90% of capacity will allow sulfation of the battery using the 10% of battery chemistry not reactivated by the incompleted charging cycle.

Heat of 100 plus F., increases internal discharge. As temperatures increase so does internal discharge. A new fully charged battery left sitting 24 hours a day at 110 degrees F for 30 days would most likely not start an engine.

Low electrolyte level - battery plates exposed to air will immediately sulfate. Incorrect charging levels and settings. Most cheap battery chargers can do more harm than good. See the section on battery charging.

Cold weather is also hard on the battery. The chemistry does not make the same amount of energy as a warm battery. A deeply discharged battery can freeze solid in sub zero weather.

Parasitic drain is a load put on a battery with the key off. More info on parasitic drain will follow in this document.

Where to buy LiPo Batteries?

The best retailer of LiPo batteries is Genstattu which sell a huge variety of batteries in many cell configurations and capacitance for very, very low prices. The website sucks, but the prices are great.

Gens Ace High Capacity LiPo Batteries

Gens Ace batteries promises extended flight time with little to no increase in weight vs. the same mAh pack of a different brand. The Gens Ace LiPo batteries allow for an increase in the fuel tank by reducing the discharge rate; a 7.4v lipo battery 5000mah pack has a constant discharge rate of 10a and a burst rate of 20a. These reduced rates can be attained on multirotor platforms, making the Gens Ace LiPo's a suitable choice.

Gens Ace is claiming increased flight times up to 20%. The packs come prewired with Deans connectors.

The Gens Ace high-capacity LiPo's are currently available in:

4s lipo batteries

3s 4000 mAh

3s 5200 mAh

4s 5200 mAh

There are many points and details I have not written about because I wanted to keep this as short and simple as possible. Further information can be found at the links below. If you are aware of sites with good battery maintenance information please let me know.