I picked up a garmin striker 4 today for my kayak. I mounted it on my kayak and looks nice but I have a problem. What can I use for a battery that is small and light? I was hoping my USB power brick would work but it does not make enough electricity to turn it on. I have the device mounted on my front center hatch and run power wire into the hatch to place the battery in there so it will be safe from getting wet. can someone point me towards a small cheap battery that can power this for 6-8 hours of fishing?

Just need a 12v battery - this one is 6"x2.5"x4" and weighs all of 5lb.

https://smile.amazon.com/Mighty-Max-Battery-ML9-12-Rechargeable/dp/B00K8V2Y8W/ref=sr_1_5?crid=3EF0C59T1050J&dchild=1&keywords=small+12v+battery&qid=1618083585&sprefix=small+12v%2Caps%2C207&sr=8-5

 

Since it's a Sealed Lead-Acid, a decent automatic-charger will handle it...no need for a specialty charger. At 9AH, it'll last you 2-3 trips between charging.

4 minutes ago, MN Fisher said:

Just need a 12v battery - this one is 6"x2.5"x4" and weighs all of 5lb.

https://smile.amazon.com/Mighty-Max-Battery-ML9-12-Rechargeable/dp/B00K8V2Y8W/ref=sr_1_5?crid=3EF0C59T1050J&dchild=1&keywords=small+12v+battery&qid=1618083585&sprefix=small+12v%2Caps%2C207&sr=8-5

 

Since it's a Sealed Lead-Acid, a decent automatic-charger will handle it...no need for a specialty charger. At 9AH, it'll last you 2-3 trips between charging.

That looks good but can I charge it with the same charger I use for my car battery?

I wouldn't unless the car charger is capable of switching to 'trickle charge' of 1-2 amps instead of the normal 10-15 amps of a standard charger. My old charger had a switch on the panel to change it from 'fast' (12amps) to 'trickle' (1amp).

2 minutes ago, MN Fisher said:

I wouldn't unless the car charger is capable of switching to 'trickle charge' of 1-2 amps instead of the normal 10-15 amps of a standard charger. My old charger had a switch on the panel to change it from 'fast' (12amps) to 'trickle' (1amp).

Mine had 2 settings one is 2 amp and one is 10 amp. Could I use the 2 amp setting?

9 minutes ago, Fred Allen said:

Mine had 2 settings one is 2 amp and one is 10 amp. Could I use the 2 amp setting?

Yep - 2amp is a trickle charge...just make sure the charger is an automatic one - shuts of or goes into 'maintenance mode' when the battery is fully charged...manual for it should tell you.

On 4/10/2021 at 3:05 PM, Fred Allen said:

I picked up a garmin striker 4 today for my kayak. I mounted it on my kayak and looks nice but I have a problem. What can I use for a battery that is small and light? I was hoping my USB power brick would work but it does not make enough electricity to turn it on. I have the device mounted on my front center hatch and run power wire into the hatch to place the battery in there so it will be safe from getting wet. can someone point me towards a small cheap battery that can power this for 6-8 hours of fishing?

Best choice for small and light is a lithium iron phosphate (LiFePO4) battery.  Even though a small lead-acid battery is rated at 9 amp-hours, that's to full discharge.  Fully discharging a lead-acid battery damages it.  

 

A LiFePO4 battery rated at 9 amp-hours will provide that much juice before reaching a damaging level of discharge, so it actually provides a lot more usable power than a similarly-rated lead-acid battery.  And the LiFePO4 batteries are much lighter than the lead-acid type.

 

You could use a small, light 5 amp-hour LiFePO4 that will probably run the sonar at least twice as long as a 9 amp-hour lead-acid battery. 

 

My figures are probably off a bit, but if you look for some YouTube videos comparing lead-acid to LiFePO4, you'll get the correct story.

 

I can run my Garmin Striker Plus 5cv for a week on my 9 amp-hour Bioenno LiFePO4 before I even have to think about recharging it.