A bit of an odd one today but it might be useful to a few people. It’s just a quick blog on batteries, as anyone in this business has a small mountain of the damned things and they are not exactly cheap. I currently have approaching $2,000 worth of batteries for my various bits of equipment with 4 batteries for the new drone setting me back $600. Some of my equipment can sit around for months between uses and I was a little sick of finding batteries that were seemingly dead or wouldn’t hold a proper charge. After investing in a number of new batteries recently I decided to spend a bit of time researching the various types. It’s been worth it as I have managed to resurrect a few of my batteries.
Getting the most out of your batteries is not so straightforward. Some batteries like to be kept fully charged others prefer to be stored at zero; some have a ‘memory’ issue others don’t. One thing you can say with all batteries, is they do like to be used. However, the various types need to be treated very differently if you want to get a long life out of them. So here are some tips for battery use, maintenance and storage.
Nickel Cadmium (NiCad) – These should be stored with zero charge as any residual charge will cause a kind film to appear, which acts as a barrier to recharging them . You should always fully discharge before charging or you can suffer from the ‘memory effect’ reducing the amount of power it will hold. When seemingly dead or they have a low capacity from poor use, these type of batteries can often be restored to good health by repeatedly charging and discharging them several times. This can kind of ‘burn’ off the film that has developed.
Nickel Hydride (NiMH) – Same as NiCad, the only significant difference is not having Cadmium, which is high toxic.
Lithium Ion (Li-ion) – No memory effect with these but they should be treated completely differently to the Nickel based batteries. For short-term storage, over a few weeks or months, charge to 100%. But for long-term storage they should be charged or discharged to around 40-45%. Check the charge every few months and ideally fully charge and discharge them every 6 months. DO NOT store these for any length of time with zero power, as they can lose storage capacity over time due to a chemical reaction similar to what happens in the Nickel batteries.
Lithium Ion Polymer (Li Po) – This is what I have read regarding my new DJI Phantom drone’s batteries and I am unsure if this is the same for all kinds of Li Po batteries. For storage of more than a week, charge or discharge them to 40%. This is apparently because they discharge very quickly from 100%. For example from 100% a battery will discharge to around 60% in 2-3 months. From 40% they will only drop to around 30% over the same period. Check the levels every couple of months and charge as appropriate. Do not fully discharge these and it is suggested to avoid going below 15%. Always allow them to fully cool before charging, equally allow them to cool before using them. If you store them long term or are regularly recharging them when partially charged, you should charge them to 100% and discharge to 10-15% every 4-6 months or every 20 charges. No batteries like to be dropped but Li-Po batteries seem to be particularly fragile.
WARNING: There have been numerous incidents of these type of batteries catching fire, generally it seems when being charged after being dropped. So if you drop one and want to charge it again, keep an eye on it and make sure it’s away from anything combustible.
Lead Acid (Car/Motorcycle) – Always store them fully charged. Ideally they need monthly use and like the others types, they like to be ‘exercised’ by fully charging and almost fully discharging them, once a year. These do not like to be fully discharged and generally speaking it is best to not take a car/bike battery below 50%. Note that deep cycle lead acid batteries for solar and marine use can cope better with larger discharges than normal car or bike batteries but again they still don’t like to be fully discharged on a regular basis. Storage without maintenance will result in ‘sulfation’, which is similar to the effect suffered by the Nickel and Lithium Ion batteries. If caught in time this can be reversed by repeated charging and discharging the battery.
Rechargeable Alkaline – Despite what the instructions usually say you should not run these down to zero before recharging. This type of battery is old hat now, not very efficient and they are not very useful with high-powered equipment. However, with correct use (not running them down to zero) decent quality Alkaline batteries (even non rechargeable ones) can be recharged hundreds of times. Don’t go sticking your Duracell’s in a charger though, without first doing some reading up. Non-rechargeable batteries have to be recharged for no more than 2 hours at a time or they can cause a fire. There are even chargers available online, they basically automate the on and off charging. This is more than a little risky if you are not confident you can monitor them properly, so I for one will not be trying it.
I hope this is useful for someone and please, whatever batteries you are using, try to recycle them as they all contain some very nasty chemicals. The NiCad’s are particularly dangerous as they have Cadmium, but none should ever be thrown away with normal rubbish.