How long should a 12V battery last for Helix-5 SI GPS?

[okumasheffield]

Just purchased a 12V battery from Sail for Helix-5 SI GPS and found out a full-charge only lasts 4 hours before shutting down the unit.

 

The fishfinder is supposed to drain 700mA

 

Here is the battery info

Brand: PBS 12V-7.2AH/20HR

 

Does it mean the battery is defective?

 

On a side note, is it a bad idea to run FF using trolling motor battery?

 

Thanks in advance

Edited August 19, 2015 by Okuma-Sheffield

[DRIFTER_016]

Make sure it's fully charged before you run it.

[adempsey]

Is that a 7.2 Amp hour battery? If so, I believe the 20HR means that it should last 20 hours at 360 mA discharge rate. You are drawing almost double that, so it should last <10 hours. Probably more than 4, but it depends on what the actual current draw is of the sonar. The average/typical might be 615mA, but not with the backlight on etc..

Edited August 19, 2015 by adempsey

[Sinker]

I run an elite 5 off the same battery for twice that long, easy.

 

S.

[okumasheffield]

Great info.

 

I now can believe the battery is defective

[Lape0019]

As for your side note, I do not believe you should be running a FF off of a deep cycle. That is, if it is hooked up to a Trolling motor only because it would cause some crazy interference.

[BillM]

You definitely don't want to be running a finder off the tm batteries.

[ecmilley]

i have the same battery in my portable set up and runs a hds-8 all day ice fishin

[Old Ironmaker]

I never had problem running my bow mount FF of a deep cycle. As well my 2 others are run directly off my cranking battery. No interference at all. I did shroud the wiring through a conduit. I just have to remember to check my amps when running them when I use the kicker to troll and not running the 115 for hours at a time. I got stuck with a dead battery once. Enough to run all electronics and live wells but not to crank. I run a portable Eagle Ultra with 2 @ 6 VOLTS for a week on a tinny or icefishing. Looks like a bad battery, have it tested at CTC, no charge.

[Fang]

most all the outdoor stores only sell the 7mA 12 V batteries. Their OK but check out any real battery store and get a 15mA. Same size dimensions except for 2" taller. On fly ins I get 4 days out of this battery on a HB798 color and the biggest thing you can do it turn down your screen brightness to get longer battery life

 

Magnacharge Batteries in Mississauga has some very cool small 12V that can be easily used for fish finders