Need a Reading on Charging Batteries

[Idunno]

I charged all my batteries last week, but never went fishing last weekend. It has been in the 20/30s at night, and another week has passed since I charged my batteries. Do I need to put them on the charger before I go tomorrow, or are the good? All batteries are in good shape, not new but good shape. Thanks in advance for advice.

[kickingback]

Batteries can drain very slowly over a long period of time. If the battery is still new (less than 6 months) it should not drain out on it's own. If it does then you may need a new battery.
If I were you I would invest in a handheld voltage meter that you can check anytime and charge as needed. Amazon.com: MinnKota Digital Battery Meter: Sports & Outdoors
I have three batteries and I charge mine directly after using and let it sit for a week or two before I go out again and even when it gets cold my batteries are holding the charge.

[CrappiePappy]

On a fully charged battery ... extreme heat is worse than the cold. I wouldn't think a week would be long enough to deplete much of the charge, unless something hooked up to them has been left running.

It certainly wouldn't "hurt" to top them off with a charger ... and you might also check the water levels in all the cells, just to make sure the coils are covered. If need be, add distilled water to the cells that are low ... but, do that AFTER the batteries are fully charged.

I've used this site for any questions I had about batteries, and the proper way to charge them : Deep Cycle Battery FAQ

... cp

[SeaRay]

CrappiePappy, I am not sure adding water after you charge is correct. If the level is below the top of the plates I think you can damage the cells. Been a while since I visited this topic but I think that is correct. We use to travel fulltime in a motorhome and our deep cell batteries were our life line so I tried to stay on top of proper maintenance. I was told this by a tech rep for Interstate Batteries at a seminar they hosted at an RV rally.
And I could be mistaken, wouldn't be the first time.

PS
OK found a link I was looking for. You should insure the plates are covered then charge them. After charging you can top off to the full level. This protects the plates and also avoids the possibility of boiling over if you get then too full before charging. So...we were both correct.

[Zinger]

If you have a good multi bank on board charger can you leave it plugged in and it will keep the batteries at the proper level and not over charge them!?!?

[SeaRay]

If you have a good multi bank on board charger can you leave it plugged in and it will keep the batteries at the proper level and not over charge them!?!?

In theory, yes, but keep an eye on the water level in the cells. Sometimes even the best chargers are a bit high on the float charge and can, over time, boil out enough water to drop below the plates. Not likely on a good charger, but doesn't hurt to check.

[midcarolina]

A good lead acid battery will self discharge at a pretty low rate about 3-5% a month............ If your charger has a maintain mode, the charger will start charging then quickly switch to trickle if the battery is charged..........