Riptide 80# Bow mount 24V w/ ipilot only lasts 2.5 hours

[iwaterdave]

Just got this installed and picked up 2 new deep cycle marine 180 reserve batteries and hooked up in 24V standard. I usually fish in an area with a mild breeze so the auto pilot and advanced auto pilot was a great feature for my 19 ft Bayliner.

My problem is due to the breeze I have to use it at 3/4 -full speed to maintain 1.5 mph trolling. Only had it out 3 times and only lasting 2-3 hours. Is this normal?

Secondly once the batteries drained enough that the GPS stopped working on the motor I turned it off and pushed the battery test button and was 100% depleted. But 15 minutes later at the dock checked it again an was 50%. Why?

 

[iwaterdave]

Still puzzled...

 

[fishrdan]

Your run times don't sound too out of the ordinary, big TM, small(ish) batteries, fighting wind/current. If you want more run time you'll need more or bigger batteries. Batteries reading 50%, 15 minutes after being depleted, I bet they would have been kaput if you tried to use them. The voltage of the batteries probably came up after resting or the electrolyte getting stirred.

I have a 70# PowerDrive on an 18'er that I use for trolling, and fighting wind and current is a battery killer. If I'm heading into wind, waves or current I troll off my main engine, then use the trolling motor when following the wind or current. Doing this I can troll for 4-5 hours off 2-Group 29 batteries with 210RC. Last trip out I had 4- group 29 batteries wired up (series/parallel) and trolled for 8 hours without running out of battery power.

I have my I/O engine rigged so I can charge the trolling batteries while running the main engine, but that requires trolling off the main engine for several hours... Still better than heading back to the dock.

 

[Silvertip]

You have all the data you need to calculate if 2.5 hours is reasonable. A 180 minute reserve capacity test spec means the battery(ies) can deliver 23 amps for 180 minutes before they are no longer able to do so. 180 minutes is three hours. Your 80# troller draws somewhere around 45 amps worst case so lets use the 75% number you mentioned. 75% of 45 is 34 amps so you are discharging the battery at about 1.48 times the test spec for the battery (25 amps). At that current draw, you diminish the test spec (180 minutes) by a factor of 1.48 so the real run time number is reduced from 3 hours to 121 minutes or a little over two hours. At that point the batteries cannot deliver 23 amps any longer but the motor may actually run at reduced power for a short time. At that point is where the locator and other electrical stuff may begin to drop out due to built-in low voltage protection circuits. Actual current draw numbers cannot be calculated with absolute accuracy because of the number of variables but adding an ammeter would be able to prove the current draw. As this example shows, you are getting very appropriate use assuming the run time is continuous or nearly continuous.

 

[iwaterdave]

Your run times don't sound too out of the ordinary, big TM, small(ish) batteries, fighting wind/current. If you want more run time you'll need more or bigger batteries. Batteries reading 50%, 15 minutes after being depleted, I bet they would have been kaput if you tried to use them. The voltage of the batteries probably came up after resting or the electrolyte getting stirred.

I have a 70# PowerDrive on an 18'er that I use for trolling, and fighting wind and current is a battery killer. If I'm heading into wind, waves or current I troll off my main engine, then use the trolling motor when following the wind or current. Doing this I can troll for 4-5 hours off 2-Group 29 batteries with 210RC. Last trip out I had 4- group 29 batteries wired up (series/parallel) and trolled for 8 hours without running out of battery power.

I have my I/O engine rigged so I can charge the trolling batteries while running the main engine, but that requires trolling off the main engine for several hours... Still better than heading back to the dock.

I have 2 group 27 and 2 group 31 batteries on the boat. Both sets wired with a battery selector to swap between each 24v sets. I'm getting more fishing time but that's a lot of weight. My 125 Force outboard is too big to use trolling into the wind.

 

[lmuss53]

Silvertips description of where your power is going is spot on. I get the same issue with the same motor on my 17' Sea Nymph. I fixed it with a 5 hp kicker, locked in the straight position and steered with the autopilot features on the troller or steered by the big motor. The trolling motor works for 6 to 8 hours when trolling at dead slow with live bait, but is out of juice after a couple hours at 1 to 2 mph. If you'll be trolling at speeds above a crawl, get a kicker.

 

[ondarvr]

I have a Minn Kota Terrova 80# iPilot, I can troll at a very low speed for up to maybe 8 hours, I do 7 hours frequently, but it's at about 1.5 mph or less on a smaller boat on flat water. I can easily see it running down the batteries on a bigger heavier boat when the winds starts to pick up.

 

[fishrdan]

Yep, 4 trolling batteries is a lot of weight, but it's better than heading back to the dock due to dead batteries. What run time are you getting from the group 27's and group 31's?

Theoretically (or at least the internet said so) batteries will deliver more power the slower they are discharged, so running the batteries in a parallel/series configuration should give longer run times, opposed to 2- 24V banks selected independently. If your battery switch will combine the 24V banks, give it a shot to see if it extends run time. I wouldn't hope for much though, maybe 1/2 to 1 hour longer with those 4 batteries.

I have a trolling plate on my main engine to slow it down, otherwise it trolls too fast. Though, with your 2-stroke, it may load up idling for extended periods, may not work well. I've had this happen when my 4-stroke engine wasn't in good tune.