| I have a Skyline 30 (30 amp) speed controller, which is mfg by SJ
| PRopo. According to the info sheets supplied with this controller it
| has a low battery cutoff, and is suitable for an input voltage of 5 to
| 10 cells (their phrasing, not mine).
And it's a pretty common phrasing. It refers to NiCd/NiMH cells.
| As I am thinking of using LiPo batteries - 2 or 3 cells - I need to know
| whether this controller is suitable
Well, work out the voltages.
5 cells = 5 * 1.4 volts = 7 volts.
10 cells = 14 volts.
2 Lipo cells = 2 *
4.2 = 8.4 volts
3 Lipo cells = = 12.6 volts
Since 8.4 and 12.6 volts are both between 7 and 14 volts, this
controller is sutiable.
| As I can see no way of changing the low batt cutoff I guess it must
| somehow set itself by sensing the input voltage, but....
... however, the low voltage cutoff may not be appropriate.
If there's really no way of changing it, the odds are good that it's
not changable (profound, huh?) and so it'll probably be fixed at 6
volts or so. Which is too low for 3 LiPos but ok for 2 LiPos.
I've found that the low voltage cutoff is not that important, even for
my planes with Lipos. When you start getting down to 3 volts/cell,
the power drops off _a lot_
(power is porportional to voltage squared,
so at 4.2 volts you get almost twice the power that you do at three
volts.) If you pay attention to your plane, and land when you start
losing power, you're almost certain to land before you get the cells
below 3 volts/cell which is the point where you start doing damage.
But sorry, I can't give you a definitive answer on the cutoff
| The LHS can't help, and the SJPropo site is in Japanese, but anyway I
| couldn't find that model listed on their site - but perhaps it was, but
| in Japanese.
Well, the email address on http://www.sjproporc.com/ is
firstname.lastname@example.org ... so maybe it's actually Korean? Either way,
I don't speak it. :)
Perhaps this URL will help --
though it's amazing just _how_
bad the translation is. It looks like
it's trying to be haiku or something :)
(Seriously, you should read the link, if only to see how bad the
Doug McLaren, email@example.com
"Bother," said Pooh as he pushed Christopher Robin into the quicksand.
Click to see the full signature.