Hi Frans
I just completed battery selection and install on 914 XS mono with both
sets of wings.
I contenplated various configurations, included
was using only 1Odyssey PC310 or Ultrastart Red with my suplimental
2.2 amp battery, or one of each 310 and Ultrastart.
I am am
electric model aeroplane guy and am not unfamiliar with pushing battery
capacity to limits.
A few comments:
****I talked to the
guy markets the Ultrastart andthe 13. The 13is just a PC545
with another nametag.Folk who sell them (13) have details that are
different than PC545, what else is new, asales brochure that is less
than accurate. I went with a PC545 with no metal jacket and a 2.2 amp
supplimental with ability to use any size batteryI want by plugging
into Sermos (AndersonPower Pole) connectors. Good chance I will make
model packs at precise voltage I need for Europa!
****You are quoting
sales brochure numbers that sound good.
"I plan to use one 5 Ah
battery on each bus, nothing more... These babies
> are able to
produce 250 Amp's momentarily each"
My question is at what
voltage? Also another question is what is service life using this battery
at a 50 plus amp draw for starting? Will such abuse cause a internal open
failure? Is it worth the added complexity to parallel for starting? If
your motor doesn't start in 5 seconds, what will the voltage be next
attempt?
****Are you happy using the very small terminals on Red?
http://www.aircraftspruce.com/catalog/elpages/atphighpwr.php
Or small terminals on PC310? (better than the Ultrastart)
http://www.odysseybatteries.com/battery/pc310.htm
If you were to use 2 batteriesI would devise a plan to use
both for starting. A sales brochure may say 5 amps, butI can almost
with a shadow of doubt state that on a colder day asking starting amp draw
you are not going to get anywhere near 5 amp capacity! Ask your one
remaining untouched battery after soaring to start up a now cold engine
(with cold oil) when it is cold and you may be surprised to find that it
will not crank as fast as you would like (low voltage).
I can
spout that my 2.2 amp hour battery can dump over 150 amps for short times
(which it can) but only for a limited number of times, at a much reduced
voltage and much reduced capacity. It is very happy to dump dump 5C though
many many times.
Bill Dube used to subscribe to Aeroelectric
and races a 0 to 60 in under 1 second electric motorcycle. He uses A123
cells and loves them. He was offering a A123 pack for aeroplane use for a
while (charging circuit that was aeroplane happy). Now that may be worth
considering in addition to a PC310, or have him make you a second battery
with half the number of paralleled cells.
I went witha PC545,
since it is mounted aft thus no need for metal jacket, aluminium #4 wires
with copper clad and a second total loss 2.2 amp battery with ability to
take along any size total loss battery to suit mission. I have a vacuum
pad mounted SD20S with LR3C from B+C.
BTW in under 10
secondsI can turn off main battery with a Flaming River race car
switch and run pump #2 direct off of total loss battery.
I have
details:
http://www.europaowners.org/modules.php?set_albumName=album258&op=modload&name=gallery&file=index&include=view_album.php
on Odyssey batteries:
Album: High amp "light" batteries, high amp
"light" fat wires, high and low amp "very" thin wires,
integral high amp bypass/buss as light as you can get with low resistance.
Y9-01-01
Last change: 04/01/09
Contains: 80 items
Viewed: 622 times.
and total loss battery:
Album: Passenger headrest to get Flaming River race car battery
switch, 9 breakers on back and plenty of electrical "stuff"
inside. Y8-12-09
Last change: 03/15/09
Contains: 45 items
Viewed: 375 times.
Good luck
Ron Parigoris
In your case if you
absolute want 2 batteries, consider the PC310s instead. Make up some of
the weight difference with aluminium wire.
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