Checking batteries
Checking batteries
Actually I was referring to commercial aircraft (apropos the Dreamliner reference) but I take your point.
I just wanted to reassure our newbies that things have changed and improved since those Boeing/Samsung incidents😊
Cheers, Doug 😎
Checking batteries
I just used the Samsung as an example.
As we know better now on batteries especially the new types are now fully acceptable and proven by the flying types who seem to have money to waste! At our local flying field, I saw a GBP7000.00 Jet blow up on take-off maiden flight as well) Follow the instructions and watch the Temperatures If they hot STOP! A good idea of temperature is at 65Deg C you can put your hand on it but it feels hot.
Used to have a local battery dealer near me who charged Lead Acid batteries in an enclosed yard he was doing about 30 car batteries a day so our locals could watch TV You can guess what happened A massive explosion because he was fast charging all the time
Regards
Ian
Checking batteries
I wish to heck we could all forget the Dreamliner (and the Samsung story).
That was a whole different battery generation and a different chemistry from our LiPos.
Both companies apparently also made some errors in the construction, installation and charging arrangements. Was still the early days of such applications and the lessons have been learned. No one worries about all the Lithium batteries in aircraft today. Do they?
I hope the doomers and gloomers will eventually stop digging up these outdated examples.
Obey the simple rules for our LiPos and they're no problem at all.
As with most things; look for the cheapest (no name)and you may well get something dodgy.
Remember; overcharge a wet cell lead acid (e.g. car battery), come into the room and light a fag or whatever - and boom goes the hydrogen / oxygen mix produced when the overcharged battery vents.
A so called SLA gel battery is also not permanently sealed. More correctly called a VRLA (valve-regulated lead–acid) battery. It will also vent inflammable gas if maltreated. Wet or gel cell the electrolyte is still diluted sulphuric acid.
NiMh batts will also revenge themselves if you mistreat them.
Read the instructions that come with your LiPo batts, buy a charger specifically designed to charge them, USE the balancing cable and they're as safe as any other 'box of energy'.
Apropos charging: Don't be deluded by the advertising and marketing blurb (the 'C' values) which indicate that a battery can deliver 20 or 40 or whatever times the current of it's capacity in Amp-Hours (Ah).
E.g. 20C for a 4000mAh battery:
More marketing blurb, 4000mAh seems more than 4Ah 🙄
Therefore 20C = 80Amps. So far so good, apparently!
BUT a perfect and fully charged battery of 4Ah can theoretically deliver 4A for 1 hour.
Or 8A for half an hour - you get the drift!
At the end of which it will be completely discharged and ruined.
Discharge at 80A and it will last 4/80 = 0.05hours or 3 minutes, if it doesn't go pop before that.
As you can (I hope) imagine the situation with the '40C' etc batteries is even worse.
Same applies for charging. Fast charging with multiples of 'C' is quoted.
Often printed on the battery cases. E.g. 10C/40C charge / discharge. 10C would be a charge current of 40A for this example😮
Another marketing ploy. Charging at such high rates rapidly destroys the chemistry of the battery and it's internal construction and drastically shortens the battery's life.
WHICH IS JUST WHAT THEY WANT US TO DO!
Cos it means we have to buy more batteries to replace the ones we just killed and pour money into the manufacturers coffers.
NEVER charge any LiPo or even NiMh at more than 1Amp if you want them to last. A 'fast charge' for me would be at 2A if I'm pushed for time🤔
Use an intelligent charger designed for your battery type (or types) which knows when to stop charging.
Check the current drain of your loads, i.e. motors and size the capacity of your battery to suit that and the endurance (time on the pond) you want and you'll get years of use out of it.
Exploit the 'C' values to the quoted limits and you'll maybe get a few days use.
After that you'll see at best a rapid deterioration of useful charge held and operating time.
At worst total collapse of one or more cells and expansion (puffing) of the battery case.
Happy sailing and respect your batteries!😉
Cheers All, Doug 😎
Checking batteries
Checking batteries
Here's a selection of the little meters a bit closer to your neck o the woods😉
Cheers, Doug 😎
https://www.amazon.com/s?k=digital+battery+capacity+checker&ref=nb_sb_noss_1
PS If an NiMh battery gets too hot to hold your finger on it then either you've badly overcharged it (and ruined it🤔) or it has a dead cell.
They all get warm when charging but shouldn't get HOT 🔥😭
Checking batteries
To check the capacity and voltage what you need is this
https://www.amazon.co.uk/Digital-Battery-Capacity-Indicator-Controller/dp/B07F391NHF/ref=sr_1_3?dchild=1&keywords=digital+battery+capacity+checker&link_code=qs&qid=1589828392&sourceid=Mozilla-search&sr=8-3
They come with many names but they are all the same inside😉
They shouldn't break the bank at around 8 quid 😊
Re Hot battery!😮
As MB already asked What type?
If the battery gets too hot to touch then disconnect it IMMEDIATELY!
Most likely it has a duff cell (or more).
If a batt has a local hotspot then that will tell you which cell is duff.
The little meters will then show 0V or a very low voltage for that cell on a LiPo.
Take it outside pronto!!
With a NiMH with a duff cell the total voltage shown will never reach the rated voltage.
E.g. If one cell of a 4.8V nominal NiMH is duff it will never show more than 3.something volts.
Hope that helps.
Cheers, Doug 😎
Checking batteries
Rick
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