Topic: running 798si from small battery

[finnyfred]

Hello,
I need to run the 798si from a small battery.
I think I have to get a sealed lead battery.

Any good idea of how much time I will get on a 12v 7Ah battery and a 12v 9Ah battery?



thank you

[mako9man2]

I believe your 798 only draws 650mA so a 9AH battery should theoretically last about 13 hours HOWEVER these units are pretty sensitive in low voltage conditions so you might want to bump the size of the battery up a bit more unless your normal trip only lasts a half day.

[sonar2000]

Definitely get the sealed battery. 10 amp or 12 amp battery should get you plenty of time.  Of course you could get two 10amp batteries. Have a spare in case you go thru the battery too quickly at times.....  Chuck

[bobcoy]

I run my 1198 on a 7 AH battery and just leave the charger hooked up. I have run for several hours and the 1198 draws twice as much.

[sfw1960]

I run my 798ci SI on the ice with this:
http://www.ebay.com/itm/12V-12Ah-Wheelchair-Medical-Mobility-Emergency-Light-Security-Battery-UB12120-/400754030912?pt=US_UPS_Batteries_Components&hash=item5d4ecd3940

12AH, the 7 amp ones get sucked up within about 4 hours with the back light up....I been there!
Warmer Wx might get you more time, but I can run all day with this one.

HTH

[bobcoy]

finnyfred. my post was in reference to running your unit at home.(with the charger plugged in). Definitely a larger one for the boat. Bob

[DiveExplorer]

I use a 9 Ah sealed battery with Humminbird 581. The specs says it drawes 400 mA.

Calculator says that it will last 12 hours. But in reality i think it is a lot less, like 5 to 6 hours. But I work mostly in cold environment and that have affect on the battery.

[Basspat66]

If you're going to be using it for any of the GPS features forget using it on that smaller battery.  You will have issues with the GPS part not working and may even burn out the internal antenna.  You may need a unit that has not GPS and does only the sonar and side to prevent any issues since those use the least power.

[sonar2000]

GPS is not the big power hog.  it is the sonar that pulls the ua draw..  But all in all a good 50 to 60 amph battery should do fine. If space is the issue then have several of the smaller batteries....Chuck

[Humminbird_Greg]

If space is a problem than ditch the SLA type battery for one of the Lithium or other battery technologies.  More expensive but a lot more amperage per square inch (and for weight as well).