I was looking to get a fish finder to take along with me on my inflatable...I have no experience with them and really have to idea how they work so I was planning to just dive right in (based on BPS reviews) when the battery issue came up.  Do most fish finders work off marine batteries? Do any work on just a few double A's? or maybe a few 9volters? how can I tell? and which would you recommend that's not too expensive?

Thanks!

Humminbird offers a portable that uses AA batteries.  There are a few more out there.

I've got one of the Humminbird portables, used it quite a bit last year.  Been thinking about selling it.

Go to walmart and get yourself a 12 volt lawn mower battery they are small and cheap and will do the job.

TD

I believe most Portable fish finders will either have replaceble AA, C, D, or internal rechargeable batteries. Read the details. It should be in the description.

I use a Cabelas one and have had no complaints so far.  I just can't justify using anything but a rechargeable.  

http://www.cabelas.com/cabelas/en/templates/links/link.jsp?id=0036388018049a&type=product&cmCat=searchFeat&returnPage=search-results1.jsp&QueryText=battery&N=4887&Ntk=Products&Ntx=mode+matchall&Nty=1&Ntt=battery&noImage=0

They make little doohickeys to hold 8 double a batteries.  (they are 1.5 volts a piece)  But, for a while, before we had the TM (and therefore large deep cycle battery) we just used an old go cart battery.  It wasn't a real good battery, as it had sat for two long, and would lose a charge just sitting for a day and a half, but it worked fine for a couple of half day expendures.  

I have one of these and I am very happy with it.

http://www.cabelas.com/cabelas/en/templates/links/link.jsp?id=0012236018201a&type=product&cmCat=search&returnPage=search-results1.jsp&QueryText=fishin+buddy&N=4887&Ntk=Products&Ntx=mode+matchall&Nty=1&Ntt=fishin+buddy&noImage=0