On Sun, 24 Apr 2016 10:34:33 -0700, Jeff Liebermann
wrote:

On Sun, 24 Apr 2016 07:55:52 -0500, Ignoramus7945
wrote:

I have a lot of things, most of which have batteries, and therefore I
have a lot of battery chargers.

My experience with them has been generally negative. The worst are the
so called "smart" chargers.

The problem is that they are often the opposite of "smart". They go
crazy and stop charging for no reason, or worse, drain the batteries.
Additionally, they fail due to things such as cold weather or
whatever, things any decently made item should handle.

The chargers, at least for lead acid batteries, would really be better
off, if they simply tried to maintain 13.3 volts or some such.

My question is, is my experience unique and atypical, or have you also
had bad experience with battery chargers.

Nope. Over the years, I've found cause to blame the battery, the
owner, the dealer, and the charger. Sometimes, it's bad combinations
of the two. For example, the charger clearly says that it's for
lead-acid flooded batteries, but the owner insists that it should
charge an AGM or Gel type battery. I've lost count of how many times
I've run into people trying to charge batteries that are obviously
dead, leaking, or dry. Sometimes (not often) the chargers are just
plain junk:
http://802.11junk.com/jeffl/pics/drivel/slides/dead-battery-chargers.html
As I vaguely recall, all but one of these blew up in service. The one
that survived and another that was not in the photo, were
pre-emptively replaced.

Smart chargers are actually better than crude chargers because they
take the decision making responsibility away from the owner. Plug it
in, walk away, and it's done. In 95% of the situations, that's fine
and will work as advertised. However, you can get into situations
where a smart charger can be fooled and will screw up. For example,
it can't tell the difference between a shorted battery and a totally
discharged battery. In order to protect itself (from fire and
liability lawsuits), smart chargers refuse to charge such batteries.
Yet, the battery is still good, but needs to be brought up slowly
until the smarts in the smart charger decides that it's worthy of
charging. If this is your problem, you can buy a charger that will do
that automagically, or you can bring it up slooooowly with a simple
trickle charger until the smart charger is happy. There are other
situations that might cause problems, but I don't want to burn the
time right now.

You can also create problems by having the battery and charger at
different temperatures or using corroded or rotten battery leads. Both
of these can fool a smart charger.

With the LiIon family of batteries, you have no choice in chargers.
It's going to be a smart charger or forget about charging. Lots of
reasons but the big one is that one tiny mistake with a LiIon type
battery and it's toast or you start a fire. Again, the smart charger
takes the decision away from the owner. LiIon also adds the need to
use a "balance charger", which equalizes the voltage of each cell.
"Equalization" can also done with flooded lead-acid cells if they get
out of balance, but for LiIon, methinks it's a necessity. Of course,
a balance charge requires a smart charger.

Basically, you have to evaluate each battery, battery charger, and
user combination together. If one part doesn't fit well, it's not
going to work. For example, you can have the worlds best battery and
smart charger, but if the owner doesn't follow the instructions, it's
unlikely to work. If you do decide to do your own thing, ask yourself
"are you really smarter than the smart charger"?

Excellent post!! Bravo!!

Gunner