Martin

That battery and that charger are horribly mismatched, causing your battery to overheat when charging. As a result, you may have caused permanent damage to the battery. I wouldn't use it for anything safety critical like a flight pack, at least not without thoroughly testing the battery out (at minimum, a good few charge/discharge cycles on a decent CPU-controlled charger, monitoring the capacity during discharge to see what the real battery capacity is). For a pack basically used for ground-based servo testing it should be good enough, provided you can find a way to charge it safely -

You have a big mismatch between battery and charger. Your battery has quite a small capacity of 500mAh, and the recommended charge rates are 50mAh (0.1C) or quick charge at 0.3C. These charge rates are pretty standard recommendations for both NiCd and NiMH. Your charger is putting out 600mA, which is 1.2C, four times the recommended fast charge rate. That would be considered faster than normal even for a LiPo. Chargers for NiCd and NiMH charge at constant current, which means the charger will adjust its output voltage as required to try to force the specified output current into th

Actually, most (all?) batteries have their rated capacities based on 20 hours rather than 1 hour. Therefore, a 2000mAh battery is actually rated to deliver 100mA for 20 hours, not 2A for 1 hour. If you try the latter you will probably see a significantly smaller usable capacity. Compare the graphs I posted earlier, which only go up to 1A. (This is particularly crazy for things like car batteries, where (say) a 40Ah capacity is still based on the idea of drawing 2A for 20 hours, despite the fact that the battery is really designed to deliver hundreds of amps for a few seconds.) However,

I think different people have shown different things for this, and there are a lot of different factors at play. Something like a receiver probably draws a more or less fixed current regardless of voltage (but may well get hotter at a higher supply voltage, as with simple linear BECs on small ESCs). Servos will move faster and provide more torque (again getting hotter), but will draw more current in doing so (partly mitigated by the fact that they are moving the same distance at a faster speed so are moving for less time). At the same time, drawing a higher current from the battery will reduce

I think it's not just the risk of the batteries coming loose. You also have the problems that you're relying on spring pressure to maintain a good low-resistance electrical contact (vibration could reduce this), and that because the contact area between spring and battery end is actually quite small you can have a small amount of corrosion on one or other surface which makes a significant difference to contact resistance. The problem with a dodgy high-resistance contact is that it may well work when everything's on the ground and there isn't much drain, but it could cause problems when you

Just to put some of the things on this thread in perspective, have a look at the discharge graphs on http://www.eneloop.info/eneloop/technol ... acity.html . Note that NiMH batteries (both the low-self-discharge type and the high capacity type) have a long section with quite a stable voltage around the 1.2-1.3V mark, and that this is quite stable across the three different current drain graphs (100mA, 500mA, 1000mA). It's quite possible that if you discharge to 1.2V at a reasonably high drain rate (like 300mA) then you're only reaching the start of this flat section. Discharging to (say) 1

Actually, it started with M4 nylons which broke too easily, then upgraded to M5 nylons which are about right (possibly still a little eager to break). This is with two screws for a very WOT4-like metal undercarriage. Martin