Humminbird piranha max 20 fishfinder

I just got a humminbird fishfinder (piranha max 20) and wanted to see what anyones thoughts were on this fishfinder  for a starter. Does any one know a good battery to recommend for it for in a kayak. 

You bought the fishfinder, then came to ask for thoughts on it I won't comment on how good the fishfinder is, but I would have picked out a different one. As for a battery, this is what I use and it lasts all day http://www.cabelas.com/product/Cabelas-Rechargeable-12-Volt-Battery/700551.uts?Ntk=AllProducts&searchPath=%2Fcatalog%2Fsearch.cmd%3Fform_state%3DsearchForm%26N%3D0%26fsch%3Dtrue%26Ntk%3DAllProducts%26Ntt%3D12%2Bv%2Bbattery%26x%3D-891%26y%3D-51%26WTz_l%3DHeader%253BSearch-All%2BProducts&Ntt=12+v+battery&WTz_l=Header%3BSearch-All+Products

Let me rephrase my statement. The fish finder came with the kayak that I bought. I would like opinions on it and what everyone's thoughts were on the type of battery that would be good to use for it.

Any type of depth finder will be more beneficial than  not having one. Just take some time to learn your settings and how others use that model. (Sorry, I'm unfamiliar with that model)
Battery type: any sla with 7mah or more should be sufficient with your finder. I run an 8 amp hr sla. It works all weekend with brightness turned up. If you have an amazon prime account, I have seen excellent prices on 7-10 amp hr batts for dirt cheap ($20-30) with free shipping. Good luck.

(Delete double post) my phone likes to do this.

Oh, got it. It will work, and it should show you your basic stuff (depth, fish, basic structure). Like Mreggmnstr said, it is better than not having one at all, but it is nothing special. Humminbirds are good though, especially since they seem to be super watertight.

The one already mentioned from Cabalas is at a good price. Or check any battery store online that sells batteries for UPS, wheelchairs, etc. as they have 12v sealed lead acid batteries in the 8 Ah capacity. Weight will be around 5 lbs. Dimension vary so determine what size will fit before ordering anything.

The 12v batteries can be charged using a standard car battery charger with 6 amp or lower settings.

The one already mentioned from Cabalas is at a good price. Or check any battery store online that sells batteries for UPS, wheelchairs, etc. as they have 12v sealed lead acid batteries in the 8 Ah capacity. Weight will be around 5 lbs. Dimension vary so determine what size will fit before ordering anything.

The 12v batteries can be charged using a standard car battery charger with 6 amp or lower settings.

6 Amp charger will supply too much current to the battery and potentially damage it or lessen its life.   A general rule is to charge at 1/10 the capacity ... meaning an 8 Ah SLA battery should be charged at 800 mA.  I believe the typical 7Ah SLA batteries have a max charge rating of 2.1 A (2100 mA).

Note that the Cabela's battery charger is rated at 500 mA.  I personally use 1000 mA chargers.

-Allen

Note: The Piranha pins and connections will definitely need to be coated with liberal amounts of dielectric grease every time you rinse it off for the day (assuming salt fishing). The pins are really tiny and corrode fast without the grease.