Friday, 16 June 2017

When "smart" isn't...................from Rico

Adding to my disdain for anything stupidly named "smart" (which I consider a ploy to dupe the gullible into paying more while getting less), smart cars, smart TV's, smart phones, ad nauseum is a "new" category of "smart devices"...vehicle battery chargers.
If you happen to have an "old" battery charger, keep it. They do what they are supposed to do...recharge a vehicle battery.
- Connect it, plug it in, and it charges.
But, they are considered "dumb" by inference, and by the introduction of "new" battery chargers that are "smart."
- Except they are NOT "smart" at all.
A "smart" battery charger will NOT charge a battery that doesn't have 1.0-1.5 volts or so remaining in it. Because it's "smart" you see.
- So if your battery is drained/dead and you need to charge it, a "smart" charger will not do you one bit of good. It won't charge your battery
- And if you're stupid enough to buy into this whole "smart" scam, you'll be shelling out a few hundred clams for a new battery because you won't be able to put a charge on it. The people who will make good money off this "smart" improvement in your life are only too happy to take your probably perfectly good battery in exchange for a new battery plus quite a few smackers from your wallet into theirs. That's the only "smart" angle I see to this, but only I'd use another word.
A workaround to this is to "jump" the dead battery until it gets enough voltage for the "smart" charger to do what it is supposed to do....charge the battery.
- Extra steps, extra BS, all because some "smart" guy made our lives better with another "smart" device.
I'm thrilled spitless.


Nelson Butterworth said...

Smart battery chargers are designed for battery types that will have a small amount of current left in it, unless the battery is at the end of its useful lifespan. For instance, any battery chemistry based on Lithium, used in almost all modern portable electronics and some electric vehicles.

Lithium batteries (including but not exclusively Li-ion, LiPo, LiFePo, lithium polymer, etc.) require very specific conditions to be met in order to charge the battery safely. If the cell voltage drops to zero, or very near it, the cell is effectively dead and can no longer hold a charge. Furthermore, if the battery voltage drops far enough prior to charging, the charging process will generate enough heat that a thermal runaway condition could occur. You do NOT want a Li-ion battery pack to enter a thermal runaway condition; once enough cells have caught on fire, the magnesium in your laptop or smart phone (or your electric car) will also ignite, and now you have a metal fire. Lithium batteries also have a limit to the number of times they can be charged before the chemistry is no longer able to hold energy, so each battery pack contains a charge cycle counter. Once the charge cycle counter reaches zero, the controller circuit prevents any further charging of the pack; the pack is now dead.

Smart battery chargers are designed to control the current and voltage being fed into the battery pack, in order to control the temperature of the pack and prevent thermal runaway (I have seen videos of this in a laptop; THIS IS A VERY BAD THING!). They will prevent charging if the cycle counter expires, or if the cell voltage drops below the safe threshold.

In some cases it is possible to resurrect a lithium-based battery pack, but it is dangerous. Thermal runaway is a Very, Very Bad Thing (TM). There is a very good reason why the FAA banned the Samsung Galaxy Note 7 from all aircraft in the US; a lithium battery pack catching fire on a vehicle which consists mostly of aluminum and magnesium is a recipe for catastrophe.

Smart battery chargers are CRITICAL to the use of lithium-based battery chemistry, which itself is crucial for all of the mobile electronics our society depends on today. Smart chargers are NOT a scam.

DO NOT try to use a "dumb" battery charger on a modern lithium battery pack, even if the voltages and currents are compatible. DO NOT DO IT! Just don't! Remember all those houses that caught fire when people got those "hoverboards" last Christmas? That is what will happen if you try to use a dumb charger on a modern lithium battery!

drew458 said...

Don't know where you buy your car batteries, but even the biggest baddest battery at Walmart costs under $100.