The battery is a single cell LiPo battery with all protection circuitry removed. That means you have to make sure you do not discharge it bellow 3.3V (best not go below 3.6V). The charge circuitry should make sure that the battery does not go above 4.2V while charging either - but that’s already done perfectly by the Telemetrum.
So, if you drain the battery below about 3.3V by leaving the telemetrum switched on, the battery will die and stay dead. The swelling of the battery is a great indication that it needs to be replaced. This is all ‘normal’ for a LiPo and nothing really to do with the Telemetrum itself. Another best practice is to discharge the battery to a long term storage level - I think that’s around 3.8V or so if you’re not actively using it for a few weeks. Another really good tip is to never puncture the battery by drilling through it or using a screw that’s too long while fitting the avionics bay - DAMHIKT! Kieran > On 1 Sep 2015, at 14:51, David Carter <[email protected]> wrote: > > I was let down by the battery last weekend. While it is probably my fault, it > meant I had to swap out the TeleMetrum for a non-trackable flight computer. > This led to an hour of whacking bushes so to speak in farmers fields. This is > what I got the TeleMetrum to prevent. So I have some questions about the best > way to care for and handle the battery. (I’m using the 900 MaH LiPO) > > When I last used the device, I’d returned from the field exhausted. I just > set the rocket aside with the battery still connected to the TeleMetrum. I > knew this would drain the battery, but I thought it would be no worse than > that. When I did take it out to charge, I found that I’d actually left it on, > so it had been transmitting until it died. Oops. So I put it on to charge > overnight before bringing it to the field. > > I’d never actually checked it until I got to the field. The battery hadn’t > charged at all. It was dead. I put it on a car charger for a little while, > but I was getting nothing. So I had to swap it out for another, less capable, > computer. When I removed the battery from the foam I had wrapped it in, I > also noticed that it had swollen, and was no longer the flat battery I had > put in. > > So my questions are: > > 1. Is it normal for a battery to fail after being fully and completely > discharged, or do I have a bad battery? > 2. Is the swelling of the battery normal? If not, what would cause this? > 3. What are some good ‘Best Practices’ for the care and handling of the > battery? > > David Carter > NAR 98850 Level 2 > KC3FEW > > _______________________________________________ > altusmetrum mailing list > [email protected] > http://lists.gag.com/mailman/listinfo/altusmetrum _______________________________________________ altusmetrum mailing list [email protected] http://lists.gag.com/mailman/listinfo/altusmetrum
