Acumen Battery Charger
by "Burn" for webBikeWorld.com
We last visited the topic of motorcycle
battery chargers about one year ago with our review of
In that article, we mentioned that our three Battery Tenders had been in
continuous use since 2000.
We're now half-way
through 2006 and the Battery Tenders are still going strong, pumping out those precious
electrons 24 hours a day, 365 days a year. We've
had zero problems with them -- that's
zero as in zip, nada, nichts.
You can't ask for much more than that,
especially for the 39 bucks each or so we paid for the
But time marches on, and the Acumen
Platinum motorcycle battery charger, popular in the UK,
is now being distributed in the U.S.A. by Riderstation (aka ActionStations, see below).
We gave away the Battery Doc in a
webBikeWorld contest last year, so I can't compare it to
the Acumen AcuMax 900 Platinum battery charger shown
But not to worry -- we consider the
Battery Tender Plus to be the "gold standard" for
motorcycle battery charger comparisons, so let's see how
the Acumen compares.
As we mentioned in the Battery Doc
article, every motorcycle in the webBikeWorld garage
has its battery connected to a battery charger as soon
whenever the bike is parked after each
This means that other than for maintenance
or repair, the motorcycles are never off the chargers when
A modern microprocessor-controlled charger is
specifically designed for long-term motorcycle battery maintenance. The
manufacturers claim that using the charger whenever the
bike is parked increases battery life and maintains the
battery at peak performance.
We don't have any actual data to prove
this one way or the other, but I can say that in all the
time we've been using full-time chargers, we've never
experienced a battery failure, so the chargers must be
doing something right.
All motorcycle battery maintenance chargers seem to
be pretty much the same, more or less. Acumen even
admits this in their mis-spelled marketing collateral:
"Our Platinum charger is just as clever as anyone elses
[sic]", they say.
So what does the Acumen have that
distinguishes it from the rest? For one thing, the
entire charger is encased in an extruded aluminum
housing measuring 6.75" x 2.5" x 2.125". Acumen
even claims that the charger is splash proof, although why anyone
would splash water on an electrically powered battery
charger is beyond me. Please do not test Acumen's
claims at home!
Water resistance notwithstanding, the
Acumen's "power brick" format is very nice. One
thing that's always bothered me about the Battery
Tender is the open vent design.
After 6 years, the
chargers are covered with dust, cobwebs and the like.
Although they haven't failed us, I wonder if the dust
will eventually short something out on the inside.
Now that I think about it, next time I have the air
compressor on I think I'll give them a blast or two to
clean them out...
If you're guessing that Acumen can
encase their charger in a near-solid block because
modern microprocessor circuitry perhaps doesn't heat up
as much and doesn't need the venting, well, I'm not so
sure. I noticed that the Acumen Platinum charger
seemed to get fairly warm shortly after it's plugged in,
so I grabbed the
Temp Gun infrared thermometer to take
The air temperature was 83.5 degrees and
the nearest Battery Tender measured 90.7. The
Acumen measured 104.1 degrees, which is doesn't seem
that warm, but feels hot when the aluminum is touched.
The Acumen case does have some rudimentary fins which I
assume can help dissipate the heat.
In any case, the form factor is
definitely one of the most important differentiators
between the Acumen Platinum and other motorcycle battery
chargers. The Acumen is shipped in a nice (but
storage container, although I'm not sure how useful this
is once the charger is mounted.
includes a very nice wall mount and they even throw in
four wall anchors and the screws. The wall mount
is designed to allow the charger to protrude from the
wall, allowing some air space for circulation. The charger can be snapped in or
out of the wall bracket if necessary.
The Acumen Platinum has a 45" electrical
lead that can be attached to one end of the charger and
is removable. The other end of the charger has a
short 17" lead with the type of connector found on the
Battery Tender. However, the Acumen connector
seems like it doesn't quite have the quality of the
Battery Tender version.
Here's a photo showing the
new Acumen on the left and the well-worn Battery Tender
version on the right:
The Acumen Platinum charger also comes with a 100"
extension lead that is handy to attach to the bike over
a sizable distance in the garage. We had to buy an
extra 25' extension for the Battery Tender. By the
way, Battery Tender has many accessories such as
extension cords, extra fittings and connectors and more
that can be ordered through most any motorcycle dealer.
Finally, the Acumen comes with two
cable harness assemblies: an alligator clip cable
harness that allows a temporary
attachment to a battery and a semi-permanent harness
that has a positive and negative lead on one end which can be
attached to the battery terminals. The connector
shown above then can be hung out the side of the bike
and connected to the charger when necessary.
Here's something important that we
learned about the Acumen connectors: apparently, the positive terminals
on the Acumen connectors are the ones that are exposed,
not covered. The positive metal terminal in the Acumen lead
is seen above; it's the "naked" or unprotected terminal.
In the U.S.A., the positive or power terminal is always
the protected terminal in these types of connectors.
This helps prevent a short or spark if the unprotected
terminal touches a ground (earth).
I double- and triple-checked this, and
the exposed terminal on the Acumen harness is positive. The only thing I
can think of is that the harness that we attached to the
battery was mislabeled at the Acumen factory, with the red, or positive,
indicator on the wrong lead.
The only reason I found out about this
is because I used the Battery Tender's 25 ft. lead to
reach to the parked Triumph Tiger. When I plugged
in the Acumen charger, it started beeping and the
Reverse Polarity LED started blinking, which, by the
way, is a nice feature.
However, it makes you
wonder -- if they have a built-in warning for reverse
polarity, perhaps they realize that some countries use
the protected terminal as positive?
of LEDs, the Acumen Platinum also has a "Power On" LED
that remains illuminated while the charger is powered
Besides the Reverse Polarity LED and beeper,
the unit includes a green "Good Battery" LED that glows
when the battery is fully charged.
LED glows while the battery is being tested and charged.
Charging is at a constant 0.8 Amps until the Voltage
stabilizes at 14.2 to 14.9 Volts. If the battery
has less than 2.3 Volts, the charging cycle will not
A "Weak Battery" LED glows if the
charger can't get the battery charged to more than 12.2
Volts. And a "Recovering" LED glows when the
battery Voltage is between 2.3 and 12.2 Volts.
charger will attempt to revive the battery and then will
automatically convert to the Charging mode to finish the
job. But a conscientious motorcycle owner would
never let a battery get that low to begin with, right?
We discovered another problem - there is
no warning if the
Acumen Platinum is plugged in to an outlet but not to the
motorcycle's battery. The green "Power On" light will glow virtually forever
you'll never know that the bike is not being charged
because there's no indicator.
The first time I used the charger, I forgot to connect one end of
the 25 ft. Battery Tender extension to the lead coming
out of the bike. When I saw
the green light on the charger, I figured everything was ready to go.
But the next day when I came out to check on things I
found that the charger had never been connected.
This is a major and, I think, crucial
difference between the Acumen Platinum and the Battery
Tender Plus. The Battery Tender Plus has a bright
red light that flashes on and off whenever the charger
is plugged in to the outlet but not connected to the
battery, a positive sign that something isn't right.
So apparently the Acumen connectors can
come loose and you'd never know it, which is not a good
thing. There is no indication in the Acumen
instructions that the Acumen Platinum charger has a
light that indicates that the charger is powered on but
not attached to a battery.
We're not sure if our Acumen Platinum
may have been one of the first designed, labeled and
sold for the U.S.A. market or not. It has a curious
"Approved By" label on the bottom that looks to be a
checklist for the factory to determine when a
prototype is ready to go.
We purchased the charger
directly and anonymously (as always) through the U.S.
vendor, so we're not sure about the purpose of this
label. I hope ours is not a prototype that somehow
got into the regular production run? That's not
uncommon and has happened to use before. Here's a photo
of the strange label, seen on the right-hand side:
The charger comes with a very basic
instruction sheet that has directions for mounting the
hanger but does not include directions for attaching the
harness to the motorcycle. No problem, just be
sure to visit the
maintenance-free battery for more info.
UPDATE: Speaking of labeling, we
also noticed no UL (Underwriters
Laboratories) mark on the Acumen charger, nor is
there any reference to UL approval in the instructions
or on the box. Many electrical products in the
U.S. are submitted to UL for a "seal of approval" on a
However, we couldn't find a UL
approval seal on any of the Battery Tenders either.
Although UL approval is voluntary, many municipalities require it for
various types of electrical devices. We're not
sure if battery chargers are included. We will
attempt to contact the U.S. distributor to learn more
and will report back.
There's not much more to report; the Acumen Platinum
motorcycle battery charger seems to do a good job as
long as it's connected.
The LED lights are useful;
the wall hanger is very nice and including the extension
cord is a nice touch. We think Acumen should
definitely add a blinking light or some type of warning
though if the charger is powered on but not connected to
The Acumen Platinum carries a 3 year
warranty. UK owners can check the Acumen (UK)
website for bargains; occasionally a box gets dented and
Acumen sells the charger at discount rather than going
through the trouble of repackaging the unit.
Acumen UK also sells accessories for the charger, like
cables and connectors.
Note: For informational use only. All material and
photographs are Copyright © webWorld International, LLC - 2000-2011. All
rights reserved. See the webBikeWorld®
page. NOTE: Product specifications, features and details may
change or differ from our descriptions. Always check before purchasing. Read
Terms and Conditions!
►Your Comments and
Please send comments to
Comments are ordered from most recent to oldest.
Not all comments will be published (details
). Comments may be edited for
clarity prior to publication.