Geebax
Captain
Australia
Offline
|
Batteries are chemical devices that obey certain electrical rules, but their internal workings are very hard to examine and control. The term 'Intelligent Battery' is perhaps wrong, because there is nothing intelligent about the battery itself, it refers to the whole package.
Each battery has a processor in it to monitor the charge condition and report to the control system. This method has been around for quite some time, as I recall Sony were one of the first to use it in their Info Lithium batteries.
There is little that a system can monitor about a battery, particularly as the cell voltage does not tell you much at all, except when it is under load. So the internal processor in the battery pack can measure the load and then the cell voltage to make an estimate of the remaining capacity of the cells in the battery.
The processor can also monitor how much charge current is tipped into the battery over a certain time, and that information is used to estimate the amount of charge that has been applied to the battery.
All this works pretty well at normal temperatures, but low temperatures can screw it up big time. For example, you might charge the battery indoors at 'normal' temperatures, then take it outside into near zero conditions. The processor has estimated the amount of charge in the battery when it was charged indoors and as far as it is concerned, that amount of charge should still be available. But it is not, because all batteries, regardless of type, hate the cold and will not deliver the expected charge.
In normal temperature operation, the information obtained by the battery is only valid for a certain time as well, and if the battery is charged and then left for a time before being used, the battery condition information stored in the battery's processor is not necessarily accurate, and it is not the fault of the manufacturer.
They make an honest attempt to track the charge condition, but it is not a precise science. So some simple rules can be applied here, and if you follow them, you should be OK most of the time, but ignore them and you may crash.
1. Charge your batteries only just before you intend to fly.
2. Store the batteries in normal temperatures, do not let them get too cold or too hot.
3. Never leave the ground on a battery that is less than fully charged, and charged recently.
4. If you fly in very cold temperatures, then halve your battery percentage estimates.
|
|