Battery Ideas for New Dragonfly 6

[Reelist]

I did a self-test with a rechargeable LifePO4 battery. The battery is advertised as "12V-10Ah-128Wh," and is lithium ion. Fully charged, I plugged it in and left it on simulator. It lasted only 9.5 hours. I need a battery that is going to give as much time on the water as I wish, yet maintain a small foot-print. Any Ideas and suggestions would be greatly appreciated. I can still return the battery.

[Bert Vega]

Lipripper had posted some stuff on the lipo's. I went with a regular lead acid with a 18amph rating. So far so good. How big of a footprint do you have to work with? I placed mine in the hull under the seat. Fits like a glove.

Here is the link to his thread

http://www.bigwatersedge.com/bwevb/s...ad.php?t=24345

[ful-rac]

If you dont want to get a battery that has a bigger "footprint" than a 10 amph...then get a true lithium ion battery, it'll be smaller, lighter,.more expensive....a major drawback is it might explode if it comes in contact with saltwater... ! Ive been using one for the last 5 years with no problems or explosions...then again i havent got it wet yet....

A Lifepo4 battery is not lithium ion for the record.

[bubblehide]

Originally Posted by ful-rac

I...then get a true lithium ion battery, ... Ive been using one for the last 5 years with no problems or explosions...then again i havent got it wet yet....

...

Wow, and to think, I got a lot of flack years back, for using a lithium ion battery.

[ful-rac]

Lithium ion battery has a pcb and will cut power if there is a short or low voltage to protect your battery and or wiring....so not to worry.

[T Bone]

We need to contact someone with Tesla automotive and have them make us the ideal battery.

[Reelist]

Appreciate all the great information. I now have a better idea of a power source.

[alanw]

If you haven't tried, you can increase the use time by decreasing the power consumption of the DF unit. Test by using an ammeter while turning down the display brightness until you get the lowest amp reading. When I tested mine, the power savings was significant while the display was still plenty bright enough to see.

[Lipripper92592]

Rule of thumb for battery discharge

Lead Acid 60%
Lithium based 80%

So a ten amp hour battery with lithium chemistry will give you about 8amp hours before you start to "hurt' the battery. This is about the cheapest "power" I have found so far.

http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

[Reelist]

Wanting to be able to utilize my Dragonfly 6 to its fullest capacity, I piggy-backed Lipripper and ordered the Tenergy Li-Ion 18650 11.1V 17.6Ah Rechargeable Battery Pack w/ PCB Protection (DGR-A). I also ordered the Tenergy TLP-2000 Smart Charger for Li-Ion/LiPo Battery Packs: 3.7V - 14.8V.

The operations manual calls for a 3 amp in-line fuse. It also calls for a 5 amp thermal breaker. Is it either/or? Thanks again.

[ful-rac]

Just a single fuse will do just fine. My fishfinder isn't fused at all, I just run mine strait to the battery. The possibility of a short is pretty slim to none, if you have wired it correctly.

Make sure that you don't get the battery wet, even if you roll it.

[momo fish]

Cool.. Thanks

[alanw]

Originally Posted by Reelist

The operations manual calls for a 3 amp in-line fuse. It also calls for a 5 amp thermal breaker. Is it either/or? Thanks again.

Forget the 3A fuse from the manual, I think it's a misprint. Their FAQ says use a 5A fuse or 5A thermal breaker http://www.raymarine.com/view/?id=7625

Use the breaker instead of a fuse if you can because it won't need replacing if tripped. I got one from WM http://www.westmarine.com/buy/blue-s...rs--P006557607

Originally Posted by ful-rac

Just a single fuse will do just fine. My fishfinder isn't fused at all, I just run mine strait to the battery. The possibility of a short is pretty slim to none, if you have wired it correctly.

Your call but I would always use circuit protection. A shorted wire smoking inside your yak (or worse) while your offshore is a disaster. There's a huge amount of energy in a battery.

Originally Posted by momo fish

And if I run a fuse does it matter which wire to connect to?

The non-grounded side is what's fused. On our plastic kayaks we don't have a grounded chassis so you can fuse either side you want since it makes no difference to the circuit. But, ground the positive side since that's what people are used to and it makes it less confusing if someone else were to work on your yak.