Poor Battery Performance Solutions
Updated: Feb 12
One of the most frustrating issues that can happen on the water is poor battery performance. If your battery isn't putting out the right power or it's charge dies quickly you can be left with an unusable trolling motor, unreliable electronics, or worse (not being able to start the boat!). All of these problems make for lost fishing time and can turn a great day on the water into a miserable one. We have been through these situations a number of times and have found some easy solutions that can get you back to optimal performance for your next trip on the water.
First thing is first - ensure you are using deep cycle batteries! Not using deep cycle batteries for anything you hope to rely on for a full day of use is asking for problems. Deep cycle batteries are designed to have the same power output until their charge drops to 20%. Regular batteries will have a drop in power output when the charge drops at all. Deep cycle batteries are also designed to be fully drained and recharged regularly without reducing the overall capacity unlike a car battery which is meant to stay charged for best performance. If you want to upgrade even further lithium-ion batteries like the Alberta Lithium or Dakota Lithium have even better power output maintenance until the charge drops to 0%, have a larger overall capacity, and are much lighter in weight.
No matter which battery we are discussing the first thing to ensure is that they are being fully charged before use. Batteries take a long time to charge. To fully charge two 100 aH batteries overnight it can take 8-12 hours depending on how drained they were. You can't expect to toss them on charge for a few hours before using and have great performance! If you don't have a smart battery charger which can alternate between high, low, and trickle current to the battery be sure to pick one up. Charging the battery at high current will often trick the charger into thinking it is full (all the ions have been regenerated from the electrodes in the battery and resistance through battery is minimal compared to the current supplied) meanwhile there are still ions to be regenerated on the electrodes. Reducing the current allows a better comparison for the charger between the resistance through the battery and will give the best representation of the current charge level. The charger itself can also be damaged and won't alternate as it's supposed to so check that your charger is actually working by borrowing another and seeing if it gives the same result before trying anything else!
Inside your battery there is liquid filled with ions what allow charges to be transferred from the liquid and onto electrodes which is what generates the electricity you use. In order to do this per design the liquid needs to cover the whole surface of the electrode. If the liquid does not then the overall capacity of the battery is reduced. The liquid in the battery is an "acid" however what this really means is it is water filled with reactive ions. Now batteries get hot when charging and during use, water evaporates more when heated, and when in dry environments. Over time as water evaporates the acid level will drop in the battery exposing more of the electrodes and reducing the capacity of your battery. The easy fix to this is to check your acid level in the battery and top up with water if it is not full! Picking up distilled or de-ionized water from the grocery store is recommended to fill the battery to avoid precipitation of any solids that may be in your current water supply that can also lead to performance issues.
Trolling Motor Battery
If it is only an issue with your trolling motor battery performance there is another very easy way to improve the performance! Often over time fishing line, weeds, and other material can get wrapped around the propeller shaft of the trolling motor. When this happens there is more friction and the motor needs to work harder in order to turn the prop. This requires more energy from the battery and will lead to it dying more quickly as well as you having to run the motor on a higher setting to keep up with that you want to do. Be sure to check behind the prop every so often to ensure it is in peak condition!