3s vs 4s LiPo for FF

[tufnik]

Recommended voltage for my Humminbird 718 Sonar is 12.5v.

Am building a battery pack; either 3s (11.1 v) or 4s (14.8v). Pack will be 3S3P or 4S3P at 6300 mah, which will last maybe 14-18 hrs.

Any reco on using either voltage?

[chex]

Wow nice. I'm only familiar with lipos for remote control cars and helis. A 10k mah 4s lipo is the size of a small trout and weighs a fraction of what a lead-acid weighs. Definitely the way to go for a kayak. Tagging along to see how this turns out.


Sent from my YakPhone using Tapatalk

[HokieDJ]

Get one of these from ebay. I got the 9800 MAH and it does last me about 7 hours for my FF but I'm thinking of getting 12000 MAH.

http://www.ebay.com/itm/12V-Portable...item4ac4e7b6ee

It's really about the mah that matters. That's the current that your FF will draw per hour. You do need the correct voltage for your FF to run though and usually it will run on a range from 10v to 14v.

[tufnik]

I have 25 lipo 2100 mah 3.7v packs sitting the shelf. Don't want to throw them away. They were for my RC planes, but I never got around to building packs.

I think the FF circuitry can handle it, so maybe 4s.

Chex,
Where do you fly? I still have RC gliders, electric cars, gas car, electric planes, electric heli and gas helis sitting on the shelf. Haven't brought them out since my interest shifted to yak fishing years ago.

[HokieDJ]

Oh nice. I almost got into heli's but the electric junk I got from ebay turned me off. It never took off the ground haha.

[clm]

I build and fly my own RC jets. I have tons of lipos but no FF. I shall remedy that soon as I can. My quad copter has a 5000mah 3s. Guess it will pull double duty. I haven't gotten brave enough to put my camera on it and get aerial kayak footage....yet.

[tufnik]

Almost forgot. I still have my fiberglass F-16. I think I flew it on 16 NIMH cells when lipos weren't that popular years ago. If I use lipos now, it should really scoot. I also have a half-finished sheeted balsa F-4. My favorites are my warplanes (Mustang, Hellcat), but my most favorites are my high speed pylon racers and my high performance F5B hotliner that draws over 130+ amps.

Helis are hard to fly, and I never flew them enough to be skilled in 3D flying.

[clm]

Almost forgot. I still have my fiberglass F-16. I think I flew it on 16 NIMH cells when lipos weren't that popular years ago. If I use lipos now, it should really scoot. I also have a half-finished sheeted balsa F-4. My favorites are my warplanes (Mustang, Hellcat), but my most favorites are my high speed pylon racers and my high performance F5B hotliner that draws over 130+ amps.

Helis are hard to fly, and I never flew them enough to be skilled in 3D flying.

Lipos are definitely bettrr . if it isn't, you may need to switch to a brushless motor if you take the F16 back up.

I have a ton of videos on YouTube. "Fed50h". I fly local fields and in the baseball stadium parking lot. Right now fishing is winning out.

[tufnik]

Nearly all my electric aircraft use brushless. I use Aveox, Hackers and Neumotors. I have brushless motors waiting for aircraft to be purchased...lol....

Saw the Fed50 on YT. Cool. I never flew a propped jet. All my jets have ducted-fans.

Yeah, yak fishing is keeping me away from RC...lol....

[echo5oscar]

I am thinking of using the headway lipo cells to build a battery. All said and done would be about 6 pounds for a 15ah battery. Nice thing about these cells, no soldering at all. They have threaded ends and you can get bus bars and just bolt it all together.

[chex]

Funny how this turned into a RC thread

I only fly mini and micro helis and quads. Nothing big other than on the simulator. And ditto... Who has time to play with toys when there's yak fishin to be done.

It would be cool to get a quad to hover over the yak to get arial footage. And spot fish...

[john from md]

OP Normal system voltage for a 12v dc system is 14.5 + or - .5. I would go with the 14.8 volt unit vs the 11 volt unit because it is close to the 10.5 cutoff voltage that many electronics applications use. Fishfinders are built to take it as many 2 stroke engines had rectifiers with no regulator and could get up to 16 volts.

Regards,

John

[tufnik]

OP Normal system voltage for a 12v dc system is 14.5 + or - .5. I would go with the 14.8 volt unit vs the 11 volt unit because it is close to the 10.5 cutoff voltage that many electronics applications use. Fishfinders are built to take it as many 2 stroke engines had rectifiers with no regulator and could get up to 16 volts.

Regards,

John

Fully charged, the 4s lipo can hit 16 volts. Under load, the pack voltage will drop to maybe 15. I guess that's still OK for a couple hours until it drops further.

[john from md]

I don't think it will be an issue as the voltage will start to bleed off as soon as you turn on the FF. How many mah does your 700 series draw? My 597 only draws 550 mah.

Regards,

John

[tufnik]

I don't think it will be an issue as the voltage will start to bleed off as soon as you turn on the FF. How many mah does your 700 series draw? My 597 only draws 550 mah.

Regards,

John

Spec doesn't say, but it has a B/W 5" screen, so I think about 200-300 mah.