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Battery charging

Posted: Tue Aug 23, 2016 11:27 pm
by rue_d_etropal
Although not specific to model railways, there was a report recently anbout the effect of leaving mobile phones plugged into charger over night and the possible damage it might cause, I presume to the phone.
Now like many I use rechargable devices, I find my electric drill very useful, until it runs out of charge half way through a job.
Just had it on charge. I think they recomment about 5 hours. It might have been slightly longer, but transformer part was very warm. Now I think many of these devices used to have cut outs so when battery charged it would stop trying to charge. I have a battery charger, a fast charger with lights to indicate when batteries charged, and a fan to cool it down. The other battery chargers I have, are slow ones which work better, and batteries keep charge longer, but there is nothing to indicate when it is charging and when battery is fully charged. That is a worry, and there have been stories about overheating electrical equipment.
Is it possible to have a reliable charging device which does it job well, and is totally safe, switching off when it has done its job.

Re: Battery charging

Posted: Wed Aug 24, 2016 1:09 pm
by docnjoj
I use and work with high power electric assist trikes and big lithium batteries, as well as my little dead rail R/C for model railroads. I use 2 really costly chargers with balancing and auto shutoff and have never had a problem.

That being said, lithium batteries are never completely safe. Many of the 1S wall chargers for cellphones have no cut off and just charge at a very low rate. This eventually kills a lithium battery.

As long as the tech belongs to the lowest bidder, beware for lithium powered devices.
otherDoc

Re: Battery charging

Posted: Wed Aug 24, 2016 11:02 pm
by rue_d_etropal
Problem is that most people don't have a choice when it comes to batteries. Lithium batteries are a fire risk,especially in Robot Wars! What also worried me was how hot the transformer/charger got. It was actually a separate item to the chargng unit, which had 2 light, red and green , on it. All they indicated was that the unit was on and that something to charge was connected.
It should not be a lowest price controlling equipment like this. I wonder how many accidents there have been.

Re: Battery charging

Posted: Thu Aug 25, 2016 2:22 pm
by docnjoj
Luckily most lithium packs are small and 1S so any fires are not major disasters. Remember those Sony laptops that tended to burst into flames. Remember Boeing lithium fires. Probably more occur than we would like to believe. Mostly any of 18650 packs like Tesla uses are pretty safe. Beware of Hobbyking type batteries, however.
otherDoc

Re: Battery charging

Posted: Thu Aug 25, 2016 7:22 pm
by rue_d_etropal
as I said, most people don't know what type their batteries are, and it was the report about effect of charging overnight of a mobile phone that got me thinking. Trouble is that I decided to switch off power to my laptop last night, and forgot to switch it back on today. It was ok at start of day, but I left it and forgot, so when I tried to log on this afternoon, there was no power. Easily fixed by switcing power on, but it has taken over 2 hours to recharge. I rarely use lapytop on battery power, but I think I will be more careful next time.

Re: Battery charging

Posted: Thu Aug 25, 2016 10:26 pm
by docnjoj
I have had real bad luck with laptop batteries and I consider them dead after about 2 years of use. I rarely have ever bought a spare, as I do all my work from home. Maybe newer laptops are better, but mine is almost 4 years old. Still works so I use it.
otherDoc