By Mark Lassagne, Pro Bass Angler and ASE Certified Master Automotive Technician explains, why marine and automotive batteries need to stay charged.
Unlike batteries for your kid’s toys marine batteries do not have memory only lack they’re of.
Most all marine and automotive batteries use a chemical reaction to create voltage. Inside most automotive and marine batteries you have cells consisting of two different types of lead plates and an envelope to hold these lead plates. Each cell is a small battery in its self and when the battery maker adds more cells you get more voltage. Along with the envelopes and lead there is a sulfuric acid solution that when mixed with the lead creates voltage.
Marine batteries have bigger or thicker plates allowing the battery to have a larger capacity basically to stay charged longer and withstand more charging cycles while car batteries have smaller plates for increased amperage.
When using anything that draws voltage (trolling motor, depth finder, live wells) from your battery the batteries are discharging where the sulfuric acid solution inside the battery changes or separates. The sulfur part of the solution then attacks the lead plates, eroding the plates and causing less plate area for the battery to hold its capacity. Also when the battery is at a low state of charge the lead plates that have been eroded can shed, casing the particles to fall to the bottom of the battery and short out the plates causing a weak cell and loss of capacity. Less capacity will cause your batteries run down sooner.
What this means is when your batteries are at a full state of charge they will last longer.
For maximum life from your battery it is recommended that you keep your batteries fully charged when possible and plugging in your boat should be one of the first things you do when you get off the water.
Note: batteries also need to be full of water and should be topped off with distilled water.