DC Battery Question??

I hope I didn’t screw up!!

I forgot to check the water level of my 2 DC batteries when I put them in the boat this Spring. I’ve noticed a dramatic dropoff in longevity of the batteries. Last year They would go all day and want more and now they go from full to low in about 4 hrs.

Please tell me this is because the water level is low! I checked them the morning and they were both low. I have filled them to recommended amount with distilled water and have them back on the charger.

I hate to have to go buy new batteries. I’m guessing they are at least 5 yrs old as that is how long I’ve owned the boat. They are Trojan SCS-225s.

Thanks.

You should charge your battery before you fill it. What happens is the water level rises when charging and you take the chance of it boiling over and spilling the electrolytes out of the battery. I really don’t think you killed the batteries five years is a good battery life. One thing you can do is check the voltage on both batteries after a charge you should have over 12 volts on both batteries. You do not need to disconnect any wires to do this just make sure to check the + and – on each battery. If either of the batteries does not have over 12 volts it has a bad cell more than likely and your good battery is carrying the bulk of the load.

Whatever the case after charging, 5 years from a battery is very good.

B, I can’t answer your question…but by the sounds of it you don’t have an on board charger. Or what some people call a “smart charger”.

I picked up a Minnkota 330 3 bank charger from Jolly Ann Marine I think it was about 3 years ago. Mostly because I hated connecting up two portable chargers and the hassle of taking them along on trips.

To my surprise, I’ve seldom had to add water…in fact I can’t recall ever having to add water although I do check them twice per year.

A regular charge “cooks” them if they are on too long and evaporates the electrolyte. This will happen even more in the hot summer days. The 330 charges them to a certain point, then drops to a “maintain” mode to keep them topped off so to speak.

I leave my 3 batteries in the boat all winter in an unheated garage with the charger plugged in. As long as there’s power to the charger the batteries stay charged and won’t freeze. I don’t know why I didn’t do this years ago.

The other benefit is desulfication (spelling) mode. Others can explain this better than I, but basically when there’s a build up on the battery plates they won’t keep a charge as long. This might cure your problem from having the plates exposed as you’ve described.

Not sure on that.

Either way…good luck!

I have a 2 bank onboard charger. It is a Minnekota MK210. I leave the batteries plugged in at times unless I’m fishing, of course.