I just ordered a Lowrance Hook 7 Reveal on clearance from  Tackle warehouse ($319 with Side scan) and I need a battery recommendation. 
 

I don’t fish tournaments, rarely fish longer than 3 hours, going to be mounting this to a kayak. 
 

Thoughts? 

I power a Helix 7 on my yak with an 18ah Dakota Lithium, it lasts 12+ hours. If you’re only fishing 3 hours at a time, you could probably get by with any 6ah - just make sure it has BMS charging.  They aren’t very expensive… 

I have a Helix 7 and I run a Nermak 12V 10aH battery. I paid $49 for it bit it's now only $39:

 

https://www.amazon.com/gp/product/B097BRKCQP/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

I previously had a Hook2 5 and used a 12V 7aH Dakota Lithium that I bought for $69. Dakota makes a great battery, but they are pricey. I will probably end up using that battery to power my navigation and deck lighting.

I ordered that Nermak, had an additional 20% off. Was delivered the next day. Thanks!

I've got a helix 7 on my kayak and bought a litime 12ah battery to power it. Very good reviews on YouTube teardowns compared to others at that price point. Still too new for me to give a good review, but I can say if this is your first lithium you'll probably need a new charger. I had a noco 1 that is supposed to work with lithium but it doesn't. I think the charger went bad so I bought a cheap lithium charger on Amazon and so far an happy with that. It's 4 amp, which is Relevant to how fast it charges. 

I am well prepared for the battery world, multiple RC battery charger setups from racing them for a few years. 
 

I was intrigued by the fact the that the Lifepo4 batteries claim you can use a traditional battery charger. 

48 minutes ago, Mossman said:

I was intrigued by the fact the that the Lifepo4 batteries claim you can use a traditional battery charger. 

IF you're very careful.

 

From ReLion...

"Sometimes using a lead-acid battery charger for a lithium battery can result in damage due to the differences in how the two observe the battery’s charging stage."

"The risk is the lead-acid chargers may wind up in fault code condition at some point, despite the Lithium battery probably having received a full recharge. The problem is that the conditions incurred during the fault codes can also cause issues and/or damage to other system electronics, and even the charger itself."

https://www.relionbattery.com/blog/are-lead-acid-and-lithium-battery-chargers-interchangeable

I’ve been using this for about 2 yrs now. All I run is my FF off it. Was a striker 4, but now a hook 9.

 

https://www.yakattack.us/10ah-lithium-ion-battery-power-kit-with-charger/

I'd pick up a battery charger that was designed to work with LiFePo4 batteries if I were you.  They're not that expensive (unless you get a big one) and LiFePo4 batteries aren't super cheap.  And with the right charger, they can last a really, really long time.  So you'll might actually save money in the long run. 

 

LiFePo4 batteries like a charging voltage of between 14-14.7 volts.  If you're old charger has an AGM function, they tend to charge between 14.4-15 volts on the AGM setting.  The regular lead acid setting is usually between 13.8-14.4 volts.  So on the lower end of the AGM function, you might be near the higher end of the lithium battery tolerance, and the higher end of the regular lead acid charger is near the lower end of the lithium battery specs.  So there's some overlap between them that could make it possible for it to work.  But it's not guaranteed.  And while it still might work out of range, it could result in either damage to the battery or incomplete charging.  

The Noco Genius chargers get a lot of love, as they're both really good and really affordable.  For a 12Ah sized battery, a 1A charger should be fine.  That'll still most likely be able to charge your battery overnight, unless you're really pushing it.  

I use 2 Nocqua 10ah batteries on my yak. One powers a Gopro and one powers a Garmin Striker 7sv, Gopro, and a Gopro remote. One of my batteries will be going on it's 7th season this year. If it craps out, I'll replace it with the same.