I fish out of a kayak and the battery life on my fish finder stinks. It only lasts around five or six hours. I've tried turning the brightness down, but then I can't see my screen with shades on. I'm running a Lowrance Hook 4x off the Berkley Battery Pack. What gives? Ideas from the pros? Thanks!

How long did you charge the battery before you used it? Do you have a volt meter to check the battery?

Twelve hours or so. I don't have a volt meter, but the pack's light was green. It should've been full. 

Which one do you have, the 2.4 amp hour or 9?

Do you have any 12V power tools? I use my Milwaulkee M12 extended batteries to power my Hook-5. Each battery is light, gets me 5-6 hours and two batteries fit in a Pelican box that the Lowrance control head stays in when not in use.

 

Just food for thought. Look forward to a Quabbin trip next Summer.

@Scott Fit's 2.3 amp

 

@DogBone_384 I've got a Dewalt drill with 2 20v battery packs, but I've no idea how I'd hook those up to my finder

I wouldn't use a 20v battery on a 12v fish finder. 

 

I use one of these for my kayak fish finder and it works and lasts a long time.  $29.99 with charger.

 

http://www.cabelas.com/product/Cabelas-Rechargeable-Volt-Battery/700551.uts?productVariantId=1205523&WT.tsrc=PPC&WT.mc_id=GoogleProductAds&WT.z_mc_id1=00046500&rid=20&gclid=EAIaIQobChMI6-rn7ojL1gIVEbnACh0bjwcnEAQYASABEgJpkfD_BwE&gclsrc=aw.ds

12 minutes ago, JG233 said:

@Scott Fit's 2.3 amp

 

@DogBone_384 I've got a Dewalt drill with 2 20v battery packs, but I've no idea how I'd hook those up to my finder

For the size of the battery you are using, I think 5-6 hours is about right. If you want to have longer battery life, you'll need a bigger battery. 

If you have a volt meter check the 20V battery's voltage across the two terminals. Also check your fishfinder's specs., which is likely to have an operating range of 11 to 15/17 volts.  If your fully charged battery reads 17 or below, you should be good to go.

 

As far as making the connection, send me a picture of the battery and I'll figure something out.  

 

If your 20V Dewalt is 18+ V, fall back and punt: get an AGM or LiOn motorcycle battery and a Pelican type case it'll fit in.  I'll help you along from there.

 

Good luck. I'll be thinking of you on Monday when I'm hunting SMB at the Quabbin.

Thanks for the replies everyone. I wish I had known to buy a 9 amp initially, but I guess it never hurts to have a backup.