Battery question

[Eagle 1]

ACTUALLY TWO QUESTIONS . DO YOU USE TAP WATER OR DISTILLED WATER TO TOP OFF BATTERIES ? QUESTION 2 : WHEN I RETURN FROM FISHING AND CHARGE THE BATTERIES (USUALLY SAT NIGHT )THE NEXT FRIDAY WHEN PREPARING FOR THE NEXT TRIP ,I MAY HAVE TO RECHARGE FOR SEVERAL HRS. TILL THEY ARE FULLY CHARGED ? ARE THEY ABOUT SHOT ? STILL HAVE NEVER FAILLED TO FINISH A DAY'S FISHING .

[CatFan]

Distilled water only.

Your batteries will discharge during storage, and some devices such as outboard motors can draw current during storage as well. Modern onboard chargers take a significant time to determine that a battery is fully charged after being connected. It's just as well to leave an onboard plugged in and keep an eye on the lights and the water level.

[CrappiePappy]

AND ... you want to charge the batteries fully, first ... & THEN add the distilled water !! Seems bassackwards to me, but it's what is recommended by battery maintenance websites.

I'm assuming that it also requires you to monitor the water level, often enough to prevent exposure of the lead plates ... since you'd probably be doing damage to your battery if you charged it up while the plates were exposed. I'd think, in that case, adding enough distilled water to cover the plates & THEN charging them up, and THEN topping them off to the proper max level, would be the lesser of two evils.

I would think that your batteries were "getting" weak, if a weeks time is all it takes to draw the batteries down enough to have to charge them for a couple more hours. Supposedly, one only has to charge an unused battery ... once a month ... to keep the charge high enough to prevent deterioration.

You could disconnect any leads, charge the batteries, then check them a week later ... to determine if the batteries are being drawn down by some connection, or if they're just not holding a charge. A good quality battery hydrometer would tell you if one or more cells in your batteries was bad or going bad.

CatFan ... correct me, if I'm off base with any of this !!

... cp

[justinp61]

I've suggested this many times to fishermen, buy a carbon pile load tester. You can catch them on sale at Harbour Freight pretty reasonable. I don't use mine a lot but it's easier than pulling the batteries out of my boat and going to the battery store everytime I think I have a bad battery.

500 Amp Carbon Pile Load Tester

[jaxsprat]

You do not want to add water before charging because during charging hundreds of little bubbles are formed in battery,raising the water level and the battery could overflow in boat if you added a little too much water. Those water ring level indicators in battery cells are designed for proper level when fully charged. You would/should be safe to do as crappiepappy said to add water before BUT only to top of plates.....................

[CatFan]

Pretty well dead on target except without knowing the charger, you can't really tell if it's actually charging because the batteries are down or just because it has a cycle it wants to go through when you plug it back in. My charger takes more than an hour to go green anytime the power goes out., even though I leave it plugged in 24/7.

AND ... you want to charge the batteries fully, first ... & THEN add the distilled water !! Seems bassackwards to me, but it's what is recommended by battery maintenance websites.

I'm assuming that it also requires you to monitor the water level, often enough to prevent exposure of the lead plates ... since you'd probably be doing damage to your battery if you charged it up while the plates were exposed. I'd think, in that case, adding enough distilled water to cover the plates & THEN charging them up, and THEN topping them off to the proper max level, would be the lesser of two evils.

I would think that your batteries were "getting" weak, if a weeks time is all it takes to draw the batteries down enough to have to charge them for a couple more hours. Supposedly, one only has to charge an unused battery ... once a month ... to keep the charge high enough to prevent deterioration.

You could disconnect any leads, charge the batteries, then check them a week later ... to determine if the batteries are being drawn down by some connection, or if they're just not holding a charge. A good quality battery hydrometer would tell you if one or more cells in your batteries was bad or going bad.

CatFan ... correct me, if I'm off base with any of this !!

... cp

[CrappiePappy]

Pretty well dead on target except without knowing the charger, you can't really tell if it's actually charging because the batteries are down or just because it has a cycle it wants to go through when you plug it back in. My charger takes more than an hour to go green anytime the power goes out., even though I leave it plugged in 24/7.

CatFan ... I have a Minn-Kota MK220 On Board Charger ... and I charge my two batteries as soon as I get home. Once fully charged (all lights green), I unplug the charger ... and even if left unplugged for several days, or a couple of weeks, when I plug it back in I get the full charge green lights within a matter of minutes. The batteries are Everstart Group 24 & 27 (early 2012 makes). I test the amount of charge with a Altus Battery Energy tester, which I've used for decades. If I leave the charger plugged up beyond the time it takes to get all green lights .... the tester shows "over 100% charge". Water levels are kept just slightly below the bottom edge of the cell cylinder's pour hole.

I keep my batteries & onboard charger in my climate controlled apartment. I've had the charger unplugged for a couple of weeks, and just now tested them with the Altus tester. Group 24 was slightly overcharged (>105%) ... Group 27 was @ 95% charge. Plugged in the charger & got a yellow (charging) light on the Group 27 line, but only for a matter of seconds & then a green light.

My questions to you, are .... is my tester lying about the overcharged state, or is the charger "top charging" the batteries while in maintenance mode (and the second I connect something to the battery, that draws current, that overcharged state would drop to the "actual" state of charge) ??

... cp

[CatFan]

cp,

MK chargers will generally go to a blinking green after the yellow, and wait 24 hours before going to the solid green. If yours goes solid green quickly, I'm puzzled.

For several hours after charging, the batteries will probably read as overcharged. That should go away overnight.

I'm not really fond of battery testers. While they can provide information, it's one of those deals where you need more information to know the whole story. I like to check the cells with a hydrometer so I know that they are all sharing the load and there are no slackers in the battery. If you have a weak cell, the charger will keep charging until the others are overcharged to make up for it, but the battery won't hold up like it should.

Chargers determine state of charge by monitoring the current the battery draws at a given voltage, so if the charger thinks the battery is charged, it has generally taken all it will take. That's assuming the battery is good.

[CrappiePappy]

Thanks CatFan ... I think I'll take my own (& your) advice, and get a hydrometer. And even if I do continue to use the meter, I'll have the hydrometer to back up or dispel what the meter is telling me.

I have never observed any "blinking" of the lights. They've always gone straight from yellow to green. It is a MK 220 (approx 3yrs old) ... Minn Kota Mk-220 2 Bank x 10 Amps 1822205 ... though it does have fused extension wires added to the battery connection wires (probably added by the previous boat owner & purchaser of the unit). The most prevalent online listing is for the MK 220D (digital ??) ... and mine does not mention "digital" on the unit (or in the link). Could this be the reason for not having a "blinking light" stage ?? Or could it be that I just don't discharge the batteries low enough to trigger all three stages of charging by this unit ??

I'm dumb as a rock when it comes to onboard chargers, as this is the first & only one I've had any experience with. Prior to this, I've always used my Shumacher 10amp charger, which I've had for over 30yrs. I just want to be sure the onboard unit is working correctly, and that I'm using it correctly ... so as not to bugger up either the onboard unit or the batteries, due to my lack of knowledge or misuse.

... cp

[Eagle 1]

i actually take the batteries out of the boat every time ( war eagle -1542 ) . I dont have a onboard charger , just a smart charger .