The C rating on a battery indicates the maximum continuous current (both
charging and discharging) for which it is designed. The C rating is
multiplied by the milli-amp hour (mAh) capacity rating of the battery.
So...
A 900 mAh 10C battery can handle continuous current of 9 Amps. (9000
milli-amps)
A 900 mAh 25C battery can handle continuous current of 22.5 Amps.
Flight electronics use only about 100 milli-amps, so either of these
batteries can easily handle the load.
(R/C cars and copters use far more power.)
At low discharge rates, the capacity rating is quite accurate. So when
draining 100 mA from a 900 mAh battery, a fully charged battery should
last 9 hours. (900 mAh / 100 mA = 9h). They last less long at higher
discharge rates. Also, you should stop and recharge a LiPo (or Li-Ion)
at about 20% discharged. (So 9 h * 80% = 7.2 h). Over discharging a LiPo
battery will permanently damage it.
So either the 10C or the 25C battery will work fine for flight
electronics. Since the 10C is typically cheaper, I'd go with that.
(Often the higher C rated batteries don't come with short circuit and
over-charge/over-discharge protection devices.)
Don't store fully charged LiPo batteries for long periods when they are
fully charged. They will create hydrogen gas and puff up. If when your
LiPos puff up, destroy them by soaking in salt water overnight. Then
throw them out. Discharged LiPo batteries are not hazardous waste.
Manufacturers store batteries at about half charge (3.85V per cell).
Regards,
Bob
On 7/11/2015 2:38 PM, David Robb wrote:
I've been thinking about moving to Lipo in my two stage ebays to get more room....
How long do the v7.4v 25c or 10c last on your Stratologger? Do you get several hours before discharged?
==================
David M. Robb
robbdm@xxxxxxxxxxx
----- Original Message -----
From: James Dougherty <jafrado@xxxxxxxxx>
To: TCC chat <tccrockets@xxxxxxxxxxxxx>
Sent: Sat, 11 Jul 2015 18:19:57 -0000 (UTC)
Subject: [tccrockets] Re: battery for stratologger CF
Don't forget JST battery connectors, you can get hoards from China if you don't mind waiting a week for shipping:
http://www.ebay.com/itm/10-Pairs-150mm-Male-Female-2-Pin-JST-Connector-Plug-for-RC-Lipo-Battery-Part-E0-/161479501111?pt=LH_DefaultDomain_0&hash=item2598eda537
The male end is on the battery, female is on the connector end. You can also order locally from Fremont here:
http://www.batteryspace.com/connectoradaptorapairofbecmalefemaleconnectors6long22awg.aspx
Or I can bring you a few (I have bags of them)
On Sat, Jul 11, 2015 at 11:12 AM, James Dougherty <jafrado@xxxxxxxxx <mailto:jafrado@xxxxxxxxx>> wrote:
Stratalogger CF uses 4-16V, I've had good luck with the 7.4v
LiPo's Bob F. recommended and have since used them in all
my flights - no problems.
I use this LiPo battery -
https://www.all-battery.com/74volt-900mah25cli-polylipobatterypackforcx2helicopter.aspx
you can also get the 10C version which is a better deal:
https://www.all-battery.com/two74volt-900mah10chighrateli-polypackforbladecx.aspx
2 for the price of one!
Get the Featherweight mag switch -
http://www.shop.featherweightaltimeters.com/product.sc?productId=33&categoryId=2
and this is the charger to get -
https://www.all-battery.com/TenergyBalanceCharger-01267.aspx
On Sat, Jul 11, 2015 at 11:01 AM, Ben Sandoval
<yobenflstf@xxxxxxxxxxxxx <mailto:yobenflstf@xxxxxxxxxxxxx>> wrote:
Which battery are you using for your stratologger cf. I'm
getting ready to order a few batteries and I'm still on the
fence. Appreciate your input.
