It's a joke. The thing is a 1.5 amp trickle charger. Something with
that low an output doesn't need 3 stages.
You can leave a 12 volt car battery hooked up to an "always on" 1.5
amp charger indefinitely without causing any harm. It will maintain a
charged car battery, but it probably couldn't charge a dead one.
Walmart sells an excellent name-brand (schumacher) 3 stage smart
charger that has custom settings for flooded, Gel and AGM batteries.
25 amps max. Less than $50.
On Jan 11, 12:34 pm, email@example.com wrote:
If it is over 13.3v 1.5a will ruin a battery, You dont know how high
or or what voltage the charger puts out, it may be the other case
where it never puts out enough. Until something is tested with a meter
you wont know.
You are wrong on several counts. A 1.5 amp charger is not really even
considered a "charger" It is a battery maintainer. It will keep a
battery that is already charged from self discharging, but that's
about all it will do. The 3 stages of a "charger" that small are
useless. If that 1.5 amp charger is putting out 16 or 17 volts
unloaded, it will be barely able to keep a car battery topped up. When
you connect it to the battery, it won't still be putting out 16 or 17
volts. I PROMISE. And what makes you think anything over 13.3 volts
will harm the battery? At such low amperage, you aren't going to heat
anything up, which is the over-voltage danger with a real charger. Gel
Cells are more sensitive to over voltage than flooded or AGM
batteries, but at 1.5 amps, even they won't be harmed by 15 or 16
volts. This thing is simply not powerful enough to harm a car sized
Depends what you mean by HARM. Yes it won't explode or catch fire or
damage it in the short term.
But if you continue to charge a fully charged battery so that the
terminal voltage goes much above 14V, it will reduce the long term
life of the battery. By long term I mean the battery may need to be
replaced after 2 years instead of after 7 years.
Not if the charger is 1.5 amps, and it is connected to an average
sized car battery. It simply doesn't have enough power to do anything
that will cause either short or long term harm to the battery. And,
once again, having "three stages" in a 1.5 amp charger is absurd and
meaningless. If you want to be paranoid, just an automatic cutoff
would suffice. Not really needed, though.
My Harbor Freight trickle charger (smaller than the one in
the discussion) electrolyzed the water out of my marine
battery, which never held a charge after that. I'd be
careful stating that a 1.5 amp charger will do no harm.
On Tue, 12 Jan 2010 11:56:02 -0500, "Stormin Mormon"
Pretty much impossible. My guess is that your battery was already bad.
That's probably why you put the trickle charger on it in the first
I have an AGM marine battery that is permanently connected to an
unregulated 20 watt solar panel that puts out about 18 volts unloaded
when the sun hits it. AGM batteries are very sensitive to over
voltage. The reason the 20 watt (2 amp) solar panel dosn't hurt the
very expensive battery, is because of the low amperage involved. With
a real battery charger putting out 10 or 20 amps (100-200watts) the
voltage would be a factor, and 14.7 volts would be the maximum
recommended charging voltage.
I have a second flooded deep cycle marine battery on a similar set up.
I haven't had to add water to it in over 2 years.
I have a "Vector" charger with separate settings for Wet, Gel and AGM
batteries and with charge-rate settings of 2, 10 and 15 Amps. Once my
Group 31 Deep-cycle battery is fully charged I set the charge rate for
2A, and it switches into Float mode from time to time as well -- but the
battery still has to be kept topped up with water.
Ransley - a 1.5 amp trickle charger will not charge a completely dead
car battery because the dead battery will immediately suck the output
voltage down well below 12 volts, where NO charging can take place.
You can't charge a 12 volt car battery with 8-10 volts coming out of
A 1.5 amp charger will also never have enough power to heat the plates
of a fully charged car battery, so all it can ever hope to do is keep
the battery "topped up" and make up for constant battery drains from
things like digital clocks, stereo tuning presets, etc, and self
You arguments would apply to small 10-12 amp hour motorcycle
batteries, not 80-100 amp hour car batteries.
On Jan 12, 6:52 am, firstname.lastname@example.org wrote:
how high does the battery terminal voltage get to AND STAY AT with the
the sun shines full only a few hours a day... an unregulated wall wart
operates 24/7 and can overcharge a car battery.. If the terminal
voltage stays above 16 Volts for a long period of time, that WILL
shorten the life of the battery.
But I will agree with you that __THREE__ stage control may be
overkill, but you do need some kind of control for even a small wall
That particular unit should work ok. It's not rocket science to
maintain or float a charge on a battery. I use something similar
made by Schauer. It was made for motorcycle batteries but works fine
on an auto battery. Nice to have a fully charged battery when the
outside temp dips below zero.
You have to buy it then test it, cut in and out V, full charge
floating Voltage. It may be good, it may be junk and ruin your
battery. Expensive ones ive seen you can test and adjust. Buy it and
My experience with a HF brand "float charger". It boiled a
quart and a half of water out of my marine batter. which
never held a charge, again. I'd put this on a lamp timer, so
it only came on an hour a day, if you leave it on.
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