Click here for a video clip that illustrates the different alarms the
LOA dishes out.
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OPENING COMMENTS
The Apogee LOA (Loud Obnoxious Alarm) is a device that allows you to
maintain the safe operating limits of a high-performance lithium battery.
It is exactly what we have been looking for to install on our LiPo powered,
19-turn brush motor Losi XXX-T. Probably one of the worst things you
can do to a LiPo battery is run it below the minimum voltage. Battery
damage and possible worse can happen if you drag a LiPo battery under
its minimum rating.
Some brushless speed controllers like the MambaMax from Castle Creations
have a low-power cut-off built in. That's a pretty slick option! But
what if you are simply running LiPo in a vehicle with a standard ESC
and a brushed motor? How do you know when the battery voltage has hit
the minimum mark and you need to stop driving it? Apogee LOA to the
rescue. While it is not a low-voltage cutoff switch, it will, as its
name implies, let you know when it is time to stop via a loud, obnoxious
alarm.
 OUR
TEST VEHICLE
We chose our ever faithful Losi XXX-T as our test vehicle for this review.
It is setup with a Trinity Chameleon 19 turn motor, stock receiver,
stock GM-V3 ESC, Apogee 3800mah
LiPo pack and Deans plugs.
LET'S TAKE A LOOK
The LOA is a pretty simple device and features a piezo buzzer (the thing
that makes the obnoxious noise), a LED alarm light (illuminates when
the alarm is going off) and a small solid state circuit board to do
the thinking. Ample lengths of wiring are installed and give you lots
of options for mounting locations.
INSTALLATION
Installation is very simple however it will require soldering. If you
are not able or equipped to solder, talk to your local hobby store or
a buddy that can help out.
Two wires need to be soldered onto the main power leads of your speed
controller, NOT your battery or you can solder them onto the controller
side of the Deans plug. Either way is fine and plenty of wire is supplied
to do either. (Side note: you could put a Deans between the LOA
and spot you will be connecting it to on your truck. That you can move
it from one vehicle to another without having to buy more than one LOA.
But hey....they are only $21.)
We pried our ESC loose and soldered the leads onto the back side. We
mounted the alarm buzzer and LED with some servo tape, bundled the wires
and zipped them up. That's it! Soldering and all, total install time
was less than 15 minutes.
TESTING
Of course when it came time to try it out, all our packs were charged
up and it was pouring rain outside. So we grabbed our DuraTrax ICE charger
and put it to work discharging the pack. When the ICE said the battery
was drained, we installed it into our truck and plugged in the battery
wires.
EEEYOOWWW! Now we know how the LOA got its name! The LOA let us know
right away that the pack voltage was low. Buzzer blaring and LED illuminated!
"Why does this have to be so loud" we asked ourselves? Why
not a QFA (Quiet Friendly Alarm)? Well, the LOUD alarm allows you to
use this on a LiPo receiver pack on your nitro truck and still be able
to hear it over the engine. Those guys at PFM/Apogee think of everything.
Yeah! The rain stopped and it was time to give it a road test. We partially
charged the battery (enough to give us about 5-10 minutes of run time)
and hit the street. After tearing up the road in front of BYT headquarters
for about 10 minutes straight, there it was.....BEEEEEEEP! There is
no mistaking that sound. We heard it loud and clear from about 40 feet
away. We quickly scurried back to the workshop and checked the battery
voltage. It was a little over 6.5 volts, the LOA works great!
IT SLICES, IT DICES...
The LOA also provides some other helpful alerts. It will beep the cell
count of the battery pack when it is first plugged in. It also gives
out two sets of 4 chirps when the battery hits 3.25 volts per cell.
Think of this as a early warning that the battery is almost depleted.
When the voltage gets below 3.20 volts per cell, the alarm and LED go
off continuously until you unplug the pack.
Click here for a video clip to see the different alarms the LOA
dishes out.
The LOA will also sound off if it has been plugged in for 60 minutes
continuously (if you forget to unplug the battery at the end of the
day). If you are geared too high and pulling too many amps, the alarm
will also sound. Basically, the LOA will sound ANYTIME it senses low
voltage at the battery.
It should also be noted that the entire LOA system is very lightweight.
Installing this device will not weigh your truck down.
VERDICT
We love lithium power. It is lightweight and powerful. However lithium
packs require different care than a NiMH or NiCD battery pack. LiPo
power can also get a little expensive especially when you start getting
into higher mah ratings. The LOA helps protect your battery investment
and for only $20, it is a cheap insurance policy. The LOA works exactly
as promised and offers a great value for anyone running LiPo without
a built-in low voltage cutoff in their ESC.
Check out PFM
distribution for the best Apogee products and customer service in
the RC world.
Here are a couple of great links that talk about lithium battery guidelines
and safety:
http://www.pfmdistribution.com/guidelines.htm
http://www.pfmdistribution.com/files/ApogeeGuidelines.pdf
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APOGEE LOA (Loud Obnoxious Alarm) 