Battery Life Hours

Hello everyone,

I am a new owner of an older 14 foot alumacraft boat and new to iboats. I am more than a bit curious how long my battery will last on the water while running my 45# trolling motor, continuous running 500 GPH bilge pump for custom livewell, fishfinder with DSI . I also took out the second seat in the boat and replaced it with a 150 QT. cooler which is going to be used as a custom livewell, I hope the boat dont sink with all the added weight that has been added, I put the battery up in the bow and the gas tank in the middle so I hope that helps. Any comments or concerns would be appreciated. Thank you

Re: Battery Life Hours

Welcome to iboats

Alot of variables there but, I have trolled upstream at "full throttle" with my 55lb Motorguide at the end of a trip on a partially charged battery and ran for 3 hours before it was dead dead, 2-3 miles from launch, engine wouldn't start, so if you run at a lower speed on a fully charged battery it will last alot longer.

I would suggest a good battery meter, maybe a multi meter to keep tabs on the battery especially if it is your only source of propulsion and a livewell timer will also save you alot of power becuase you only run the pump for 30 seconds or so every 3 minutes, really no need to run it all the time, they make adjutable ones to that you can taylor the run time.

The fish finder uses very little power, the pump and the troller are about the same at alot, I put a SWAG (scientific wild a** guess)of 4-5 hours to be safe

As for the livewell 150 qt is 37.5 gallons, even at half full that is 150lbs + battery, gas motor and you, I would think you are getting close to the weight limit of the boat.

Re: Battery Life Hours

i will do a wild a** guess as well ..............

motor (6HP), 50 lbs, trolling motor (50FPS), 40 pounds , battery 50 pounds (sears diehard marine group 27M), livewell at max 300 pounds use the half full formula still 150 pounds, we will say 450 pounds max without anyone in it ..............fish finder and bilge 2 pounds each max, not even a blip on the radar.............

okay max of the boat should be around 750 max

things to consider,

1) what did you do to support the sides of the boat when you pulled out the seat, it is a part of the stability and keeping the sides where they are ..........

2) battery SIZE matters!!! I use a groups 27 marine diehard, have been out for 8 hours with lights running, minn Kota 50 pound thrust transom mount ( it's a bad a** motor), fishfinder and stereo going and still have 70% charge left in her, it was worth every penny for it.........

my bilge however never runs.............which as far as i am concerned it is a GOOD thing

we have some lakes up here, that are trolling only, no gas allowed at all, so i set this up as plan C............

Re: Battery Life Hours

The amount of time you can run is based on the RCA rating of the battery. That rating is in minutes and is caculated based on a 25amp continuous load. Right... well that don't help much if you don't know the load or if it's constantly varying so the best way to find out is through use. I just ran mine through a test and after 3 hours my two group 29 batteries with a combined RCA of 420 minutes were down to 90% charge on each battery in a parrallel set. But 90% is 90% left to zero and we never take our deep cycle batteries below 40% so 90% on my meter is not 90% of the RCA its actually 74.28% of the RCA remaining. Now we do the math and some "good measure" rounding and we'll see that I ran for 180 minutes and my average load was about 17amps. Thats only 68% of the 25amps that I'm allowed so my new RCA is really about 700 minutes or around 11 hours.

I was told by the folks at Interstate that the RCA is just as what it say's "Reserve" and at 40% charge the reserve is conisdered depleted.

Re: Battery Life Hours

Thanks for the warm welcome, in response though to everyones messages the battery that I am using doesnt say RCA at all. Here is the info about the battery (650 CCA) (810 MCA) (150 RC) its a marine/RV deep cycly from Farm and Fleet. As far as the weight of the boat, I am not sure but I have a 25HP evinrude long shaft and a minn-kota Traxxis on the transom with a 150qt. cooler in the middle with a bilge pump inside as a home made livewell and the 6 gal plastic gas tank in front of that towards the bow, the battery sits on the seat at the bow. Any comments appreciated yet again. Thanks

Re: Battery Life Hours

5150abf said:

Welcome to iboats

Alot of variables there but, I have trolled upstream at "full throttle" with my 55lb Motorguide at the end of a trip on a partially charged battery and ran for 3 hours before it was dead dead, 2-3 miles from launch, engine wouldn't start, so if you run at a lower speed on a fully charged battery it will last alot longer.

I would suggest a good battery meter, maybe a multi meter to keep tabs on the battery especially if it is your only source of propulsion and a livewell timer will also save you alot of power becuase you only run the pump for 30 seconds or so every 3 minutes, really no need to run it all the time, they make adjutable ones to that you can taylor the run time.

The fish finder uses very little power, the pump and the troller are about the same at alot, I put a SWAG (scientific wild a** guess)of 4-5 hours to be safe

As for the livewell 150 qt is 37.5 gallons, even at half full that is 150lbs + battery, gas motor and you, I would think you are getting close to the weight limit of the boat.

Click to expand...

I have no clue where to get a timer for the livewell!

Re: Battery Life Hours

Welcome to iboats!

confused_fisherman said:

I have no clue where to get a timer for the livewell!

Click to expand...

Might I humbly suggest here?

Re: Battery Life Hours

thanks, they look like they will do. I appreciate the info

Re: Battery Life Hours

Davem3 said:

2) battery SIZE matters!!! I use a groups 27 marine diehard, have been out for 8 hours with lights running, minn Kota 50 pound thrust transom mount ( it's a bad a** motor), fishfinder and stereo going and still have 70% charge left in her, it was worth every penny for it.........

Click to expand...

Just a reminder to all that a Sears DieHard = Interstate = WalMart Everstart = Autozone Duralast = etc etc. They are all the SAME EXACT BATTERY which is manufactured by Johnson Controls. Don't pay more for an individual brand name.

Re: Battery Life Hours

The RC designation on your battery IS the reserve capacity expressed in minutes (150 in this case) at either a 25 or 23 Amp draw. So if your continuous load was 23 amps (or 25) you would run 150 minutes (2.5 hours) before the battery could no longer deliver 23 (or 25) amps to the load. You said you have a troller but didn't indicate what thrust. However, maximum current draw for a troller is about 10% less than the thrust. 50# = roughly 45 amps. 55# = roughly 50 amps at 12 volts. You don't need to run a livewell pump all the time so the timer is mandatory and they are not expensive. As you can see, just the troller will draw more than the 23 amp test spec for the battery so that means run time must be reduced accordingly. Lets use 46 amps as the current draw for the troller. Since thats double what the battery test spec is, you cut the RC in half. So 150 minutes becomes 75 minutes. This is of course worst case since you would not run the motor wide open all the time. It's all very simple math. Add up the current draw numbers and apply it to the RC of the battery and its test spec.

Re: Battery Life Hours

I've come to the conclusion that trying to determine how long my trolling batteries will last using their stated numbers, whether Reserve Capacity or Amp Hours, is an exercise in futility. There are just too many variables involved. If you have a battery, take it out and see how long it lasts under your fishing conditions. If you need a battery, buy the biggest one with the most Reserve Capacity your battery space can handle and that your wallet can stand.

It sounds like your TM is on the transom yet you put the battery at the bow. If you don't have room in the back it makes sense. If you have room in the back, you would get more power to the TM with the battery in back.