Why use a 7, 8 or 9 amp hour battery?

[holehopper]

How many times have you used your flasher all day and by the time you get home, the battery still reads 80%?  If you ask the question, I think most people will tell you they can run their flasher for 2 or 3 days without charging it.  In reality, most of us fish 6 or 8 hours at a time and then go home. 

Given all of that, why are we lugging around a 7, 8 or 9 amh battery when a 5 amh 12V battery is about half the weight and could easily run a flasher all day?  Just curious if anyone has tried a smaller battery (I know there are lithium options, but they are expensive). 

[kingfisher22]

...because for me, if my depth finder dies, I'm going home.  It's not worth the risk.  My flasher battery is the original battery (must be 8 years old) but it still lasts the whole day.  After all this time though, at the end of the day it's close to dead.  I'm thinking if I used a 5 amp battery I probably would be on my 2nd or 3rd one by now.  For the extra years and security the bigger battery provides me, I'll deal with the weight

re\\\

How many times have you used your flasher all day and by the time you get home, the battery still reads 80%?  If you ask the question, I think most people will tell you they can run their flasher for 2 or 3 days without charging it.  In reality, most of us fish 6 or 8 hours at a time and then go home. 

Given all of that, why are we lugging around a 7, 8 or 9 amh battery when a 5 amh 12V battery is about half the weight and could easily run a flasher all day?  Just curious if anyone has tried a smaller battery (I know there are lithium options, but they are expensive).

[Gills-only]

I look at it this way, a smaller battery will start my car also, but I don't want to fish all day and get to car to find out battery dead or too weak to start it. I always go with the biggest I can get, rather have some left over than not enough juice!!

[hardwater diehard]

Discharging the battery to 80% of capacity isn't a good thing ....past 80% even worse ...recharge after each use.

4:09 mark

[bee]

I have been using 4.5 amp battery for years now. No problems.

[Kevin23]

You can't go much smaller than a 4.5 or 5, otherwise it is too light and most flashers will teeter forward and be off balance when carrying. Most of the time my HB says full or just under full charge at the end of the day.

[Lobes]

My Vexilar came with a 7AH battery. When that gets too heavy to lug around I'll give up ice fishing. For now this crabby old timer will stay with what works for me ...

                                                                               
Lobes

[3300]

it's better to have too much than to stress electronics. lead acid batteries were designed to have a charger on them when ever in use. so using sonar like we do is not ideal for the electronics as it is. to make it so the power source hold less amps, is not some thing i would ever do. same amps, but lighter maybe, but i am not so old i have to worry about a few pounds.
they only weigh 10 pounds with the sonar. the auger weighs more and that goes to each hole too.

12 volt appliances were designed to have 14 volts going to them in most cases. our sonar shows how many volts are left, but not how many amps are left. we do know that amps are carried by volts tho, so the lower the volts the less amps can be delivered and the more the battery is depleted of it's charge to carry both amps and volts.

the electronics aspect of all of this is the values per individual component. each has it's accuracy/tolerance in specs rated with-in plus or minus 5/10% roughly. these components accuracy is provided the required voltage is constant at the given voltage they were designed to use. so these values fall off when under/over powering them. this doesn't mean then device will fail right away, but it does take it's toll on the longevity of them.
these variable conditions are known to us. the under powered power source is called a "brown out". that's the condition we go fishing with our electronics. the further we push the devices capabilities of working properly in brown out conditions the harder it to function correctly.
99% of sonar failures are due to the batteries performance.

lead acid batteries do not have a self protect circuit on board like lithium and lifepo have. those circuits shut down the battery at a pre determined voltage. in most cases it is at 2.7 volts per cell for the under voltage circuit. the shelf charge is 3.7 volts. this means you only get one volt from them. it does not say how many amps you get from them tho. that is based on the capacity of the cell.
these batteries benefit from having 50% of the charge for long term storage.

so lead acid batteries suffer from abuse by not lasting as long when you abuse them the way we do. the more discharged they become the quicker they will need to be replaced.
these batteries benefit from keeping them fully charged.
to compound these issues, we subject them to freezing temps. these temps affect the self discharge rate. look at your car battery. is shows you cca ratings this means cold cranking amps. cold means 32 degrees fahrenheit.

look at non chargeable cell. the typical voltage of those are 1.5 volts and when new are about 1.60 volts. when the battery reaches it's shelf charge of 1.50 volts it is technically dead.  this doesn't mean the device it is powering will not continue to function, but is it then under powered.

same thing for rechargeable 1.20 volt cells.

you could take more than one smaller battery. when/if it gets weak swap it out. i take two all of the time. my sonar never needed the second one, but it's there. the second one is for led lighting. i could put two in the small ammo box that i only carry one in now.

don't forget you could charge them from your cars charging system. you can buy or build a simple lighter/charger adapter. nothing to add to the circuit. just the ends for your battery and a lighter plug and a fuse of around 3 or 4 amps.

hope some of this helps answer your question.

[Gills-only]

I see the new ultra packs come with a 9 amp battery

[walkndude]

With an 8ah battery I can forget to put it on the charger and not ruin the next day's fishing. I can even forget two nights in a row. I'm sure I'm not the only one that always has an extra battery in the sled with me either.

[markinohio]

LOL, I drag around (2) 10 amps in my fishtrap because I’m too paranoid about losing my fish finder during a hot bite....Even have them in a cooler to keep them insulated.

[dekatronic]

Dammit I just bought a 7 amp battery on the weekend! But I usually recharge at the end of every fishing day so I should be good.

Good topic for discussion though, as l can now see there are a lot of benefits of getting a higher amp battery

[jiignut]

Been using a 4.5 battery for years and the difference in weight is noticeable and appreciated. Even have a 12v receptacle hooked up for cell phone and glow jig charging light. I threw the bulky case away day one. Slim, trim and light. The space on both sides of smaller battery i have pvc rod butt holders. I'm so lazy I even extended the loop handle up about 16" to not have to bend over so much to grab and move. Real nice hole hopping set-up.

[holehopper]

Jig:  What sort of run time do you get from your 4.5?  Thanks!

[Chris338378]

I'd rather have power to spare than not enough. 

[bee]

Jig:  What sort of run time do you get from your 4.5?  Thanks!

I run the 4.5 amp and have for years. Like 3 years ago i switched to the 4.5 lithium. It has never gone dead while on the ice. Say 4 hour trips. I is super light and needs no special charger.

http://www.powerstream.com/LLLF-12v-4.5ah.htm