Best battery type and charging system?

I want to equip my kayak with the Raymarine dragonfly 7. I'm not sure what type of battery to get and am open to suggestions. I also want to equip the set up with a trickle charge/battery tender system that I can leave plugged in without harming the battery. Just unplug and head for the water with a full charge. I would like a battery that is strong enough to support the fishfinder/chart plotter all day, some LED lights that I intend to mount throughout the kayak, a USB charging port, etc. maybe hobiecat's aerator one day. Any and all tips for the battery and on-board charging system welcome.

I use a battery tender that was built for motorcycles. I can leave them plugged in for as long as I want with no worry of overcharging them. As for a battery you want a SLA battery with at least 9 amp hours. The 7" units will be fairly power hungry so you can go bigger but they weigh more.

I use a 9ah SLA battery on my D7 and it lasts 7-8 hours as long as you charge it correctly to 14.5v.

I considered getting the lithium type batteries for less weight but I can't justify the price.

I had a 7ah and it lasts 6 hours for me. Charging system? I use a manual trickle charger (old Crafstman 2/10/50a) and put it on a timer. I check the charge using voltmeter. I do have a HF float charger to keep it charged.

A lot of people use the Noco Genius chargers. I have one also. I have heard from a reliable source that the Schumacher chargers sold at Walmart are just as good for less money.

I use a battery tender that was built for motorcycles. I can leave them plugged in for as long as I want with no worry of overcharging them. As for a battery you want a SLA battery with at least 9 amp hours. The 7" units will be fairly power hungry so you can go bigger but they weigh more.

+2

I use small cheap ($40)jumpstarter box from Kmart. Charger built in ,just plug it in no worries. Powers my hummingbird 597 di around 10 hours. Cut the large gator clips off and solder on plug of your choice.

I own a Dragonfly 7. Currently using 12v 9AH Deep Cycle AGM battery and use a Battery Tender for charging.
I got the charger at Walmart for around $39.

I am in the process of switching to LiPo batteries.  Once its working I will post a review. 

I own a Dragonfly 7. Currently using 12v 9AH Deep Cycle AGM battery and use a Battery Tender for charging.
I got the charger at Walmart for around $39.

I am in the process of switching to LiPo batteries.  Once its working I will post a review.

Would love to hear about this once you're done. Do you know what brand you're going to use for the LiPo battery?

Two bricks:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18631

You dont need to get the most expensive charger and the most expensive battery to run your FF.  What you need is a large enough battery to run your unit all day but not go past 50% capacity that you take good care of, and use a 3 phase (aka float) charger for it:  http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

Two bricks:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18631

Dragonfly 7 power consumption is 8 W at full brightness.  Battery capacity rating is 10ah / .67 results to 14.9 hours battery life.

Battery Life = Battery Capacity in Milli amps per hour / Load Current in Mill amps

I'm currently testing a solar charger that seems to be able to charge my battery ++ with a Lowrance chirp 5 unit all day and into the night with plenty of power to spare. Going on my 7th trip W/O charging my battery except for the solar panel ($35.00!!!!) Gonna let the cat out of the bag soon. Super easy plug and play......