DeepCycle Battery Life

[TrollnDrift]

I was wondering what the run time of a typical deep cycle battery is when running a 55lb terrova trolling motor at 90% I am not sure if i got a false charge or if my battery is failing. I only made it about an hour yesterday trolling via the terrova, then it auto shut down for low voltage. The level indicator was down to one bar no load, however it was up to 3 of 4 bars when i got home. The battery is getting old so it may just be bad but thought I would ask.

[delcecchi]

I was wondering what the run time of a typical deep cycle battery is when running a 55lb terrova trolling motor at 90% I am not sure if i got a false charge or if my battery is failing. I only made it about an hour yesterday trolling via the terrova, then it auto shut down for low voltage. The level indicator was down to one bar no load, however it was up to 3 of 4 bars when i got home. The battery is getting old so it may just be bad but thought I would ask.

I did a quick search on current draw and got 30 amps at .9 for that motor. A typical deep cycle battery has a reserve capacity of 160 to 180 or about 60 to 75 amp hours. So two hours or so at 30 amps will be all the battery is capable of .

[musky hunter]

That life sounds a little short. I have an older Minkota 55 lb. thrust autopilot. With a new battery I think I would go a little longer, maybe 3 hours at a high thrust, but I wouldn't expect much morel. A direct comparison is difficult since I never set it and forget it for that length of time. You didn't mention the age of your battery, but it seems every 3 years or so I have to replace mine. Sitting outside all winter is never good. Maintenance is critical, check your water level because frequent charging evaporates water, carried away with the hydrogen that is generated. And that reduces battery capacity. Use distilled water if it needs more.

[TrollnDrift]

Battery is getting pretty old, i think about 3 years. I do check up on the water level, and keep it inside over winter on a maintainer. I might try moving that battery to the back for the engine and depth finder, and replace the terrova battery first.

All in all I expect the batteries to be failing, just wanted to check into the true expected lifespan.

Thanks Erik

[Northlander]

3-4 years on a marine battery is about average.

[BobT]

Quote:

Sitting outside all winter is never good.

A bit off topic but actually, sitting outside in winter is probably better than inside IF you properly maintain it. That is, keep your electrolyte level correct and make sure the battery remains charged. If you don't take the time to maintain it properly then yes, there's a risk of freezing which would be very bad.

[Jeremy airjer W]

Quote:

I do check up on the water level

I'm almost embarrassed to admit it but I have never checked the water level in my deep cycles. My current one has not been lasting very long and I figured I am due for another. I checked the water level tonight after reading through this the other day and wouldn't you know, I added almost 3/4 of a gallon........, . It's on the charger, we will see if it comes back around,

[TrollnDrift]

I also just checked mine to see, it must have been longer than I thought since i checked it, all plates were submerged but close to being exposed.

[Xplorer]

One of the batt's on my 24volt Terrova 80# just hit 7 years old, the other is 2 years. I keep thinking its gonna puke, and have it checked each spring at Interstate, but its still in good shape. I will say that I have gotten an average of 5 years of use out of my 27 series Interstates over the last 17 years.

[Whoaru99]

I did a quick search on current draw and got 30 amps at .9 for that motor. A typical deep cycle battery has a reserve capacity of 160 to 180 or about 60 to 75 amp hours. So two hours or so at 30 amps will be all the battery is capable of .

Bear in mind that RC is typical measured at 25A draw. If you draw off faster than 25A you won't get the advertised RC. At 30A I wouldn't expect half RC, but I think it'll be more degredation than just a straight ratio. The harder you draw on a battery the disproportionately less total Ah you can get from it.

This is why two 12V batteries in parallel will run a trolling motor longer than the same two batteries used one at a time.

[Whoaru99]

I'm almost embarrassed to admit it but I have never checked the water level in my deep cycles. My current one has not been lasting very long and I figured I am due for another. I checked the water level tonight after reading through this the other day and wouldn't you know, I added almost 3/4 of a gallon........, . It's on the charger, we will see if it comes back around,

It might still work to some degree, but it'll never be the same. The capacity will be considerably impacted. Last one I did that to would never hold more than about 12.45 after disconnecting the charger. That's roughly 75%, and it seemed a very weak 75% at that.

[harvey lee]

On average, I get approx. 5 years out of my trolling motor batteries. I had a couple Optima's, only got 5 out of them, no more spendy batteries for me.

[hamms-scooter]

Ever tried Oddysey Batteries? I run a 55# traxxis on the transom of my boat and I would recommend that motor to anyone with a 14 or 16ft boat. I am wondering then as read above if I got another battery and hooked them up in parallel if that would be ok. Would make a camping trip with no way of charging worth it...

[Whoaru99]

Ever tried Oddysey Batteries? I run a 55# traxxis on the transom of my boat and I would recommend that motor to anyone with a 14 or 16ft boat. I am wondering then as read above if I got another battery and hooked them up in parallel if that would be ok. Would make a camping trip with no way of charging worth it...

You could use the two batteries singly, or in parallel. Putting them in parallel will give you a bit more total run time because the discharge rate is spread between two batteries. Slower discharge rate = more total amp-hours you can get.

What sucks about your camping scenario is leaving a battery in a discharged state is one of the worst things you can do to it. I understand it's not always possible to fully recharge batteries after every use, but that should be the goal. The batteries will last longer.

[hamms-scooter]

Thanks!