Charging after watering the batteries

[FourPoints]

On Saturday I noticed the built in hydrometer on one of my batteries was no longer showing the green "fully charged" ball in the window, even though the Genasun was reporting a full charge, so I checked the the water level in my batteries. It wasn't too bad, but between both group 24's it did take about 12-16oz to refill (I spilled some so it's hard to say exactly how much it took). Immediately after filling them I noticed the built in hydrometer started showing the red "recharge" ball, I assumed this was just because it would take a while for the water I added to mix with the water and acid in the battery... For the remainder of the afternoon the charger kept jumping between float and bulk stages, and the red ball seemed to stay in the window, although the black "partial" charge ball was starting to pop up to the surface again.

I haven't been back down to the boat since Saturday to check, but we have had plenty of sun until today to keep charging them up. I will be down checking them tonight, but not until after the panel is shaded by the sport fisherman that recently appeared next to me so I won't be able see what the charger is doing...

How long is does it normally take before the batteries return to a normal charge state after adding water to them, and does any of this seem out of the ordinary?

 

[Maine Sail]

On Saturday I noticed the built in hydrometer on one of my batteries was no longer showing the green "fully charged" ball in the window, even though the Genasun was reporting a full charge, so I checked the the water level in my batteries. It wasn't too bad, but between both group 24's it did take about 12-16oz to refill (I spilled some so it's hard to say exactly how much it took). Immediately after filling them I noticed the built in hydrometer started showing the red "recharge" ball, I assumed this was just because it would take a while for the water I added to mix with the water and acid in the battery... For the remainder of the afternoon the charger kept jumping between float and bulk stages, and the red ball seemed to stay in the window, although the black "partial" charge ball was starting to pop up to the surface again.

I haven't been back down to the boat since Saturday to check, but we have had plenty of sun until today to keep charging them up. I will be down checking them tonight, but not until after the panel is shaded by the sport fisherman that recently appeared next to me so I won't be able see what the charger is doing...

How long is does it normally take before the batteries return to a normal charge state after adding water to them, and does any of this seem out of the ordinary?

You'd be best to use a shore charger or alternator and get the batteries down enough to go into absorption mode at a voltage above gassing. Gassing usually occurs at about 14.4V. This will "bubble" the electrolyte and cause the added water to become one with the rest of the electrolyte. A float voltage won't do as good a job as simply firing it up at a 14.5+ volt charge will but will still with time end up at the same place.

Part of the issue may be that you are using batteries with a charge indicator/sight window and IIRC you have dissimilar batts in the same bank?

12 - 16 oz is over 1 oz per cell and within the realm. 1/2 oz per cell would be a better maintenance schedule on a group 24.

 

[FourPoints]

You'd be best to use a shore charger or alternator and get the batteries down enough to go into absorption mode at a voltage above gassing. Gassing usually occurs at about 14.4V. This will "bubble" the electrolyte and cause the added water to become one with the rest of the electrolyte. A float voltage won't do as good a job as simply firing it up at a 14.5+ volt charge will but will still with time end up at the same place.

The engine peak output is around 14.5-14.8v after installing the dumb regulator, so that's probably where the gassing came from.

Part of the issue may be that you are using batteries with a charge indicator/sight window and IIRC you have dissimilar batts in the same bank?

guilty on dissimilar batteries, but the one with the sight window is a very nice and new AC-Delco marine deep cycle group 24 rated at 86AH (yes 86AH from a group 24), the other battery will be replaced with a matching 86AH deep cycle next season, even though it is still testing fine and holding a good charge.

12 - 16 oz is over 1 oz per cell and within the realm. 1/2 oz per cell would be a better maintenance schedule on a group 24.

we did a some longer distance trips in July and Aug that ended up being 100% motoring due to the wind being non-existant, and probably ended up putting around 50 hours on the motor, so that's where I beleive the off gassing happened, but I will be better about monitoring them going forward.

 

[FourPoints]

checked again last night (ended up not having time to make it down Wed), battery was showing the proper green "charged" ball in the hydrometer, and judging from the 13..1v showing on the multimeter, the batteries were coming down from float stage (it was overcast and the sun was pretty much down at that point), so everything looks like it's in good shape again.

 

[sailcruiser]

checked again last night (ended up not having time to make it down Wed), battery was showing the proper green "charged" ball in the hydrometer, and judging from the 13..1v showing on the multimeter, the batteries were coming down from float stage (it was overcast and the sun was pretty much down at that point), so everything looks like it's in good shape again.

Great! We haven't been as lucky. Doing a big refit in the Spring. A question nagging me though after reading this a few days ago is this: under normal circumstances shouldn't the water be checked and then charged? Then checked again after that? Coming from a sealed battery into wet cell with a new purchase. SC

 

[mitiempo]

FourPoints

You would be better off to keep the Delco battery as a start battery and purchase a true deep cycle battery for house loads. The Delco is a hybrid battery, not a true deep cycle, and not as tolerant of deep cycling as house batteries should be.

 

[Maine Sail]

FourPoints

You would be better off to keep the Delco battery as a start battery and purchase a true deep cycle battery for house loads. The Delco is a hybrid battery, not a true deep cycle, and not as tolerant of deep cycling as house batteries should be.

And I can't figure out how in the heck they give it a 86Ah rating other than it is possibly an inaccurate rating. Problem becomes if the Ah rating is bad to begin with then your drawing them deeper than you probably should be..

 

[wetass]

I could be wrong, but I believe some AC-Delco batteries are made by Johnson Controls. I found out the hard way (my fault for not getting the magnifying glass out to read the fine print) that some JC batteries are rated at a 1 amp/hour discharge rate not a C/20 rate. So if its a JC battery and doesn't specifically say C/20, I would guess its not apples to apples with other batteries.

 

[FourPoints]

Just snapped these with my phone, not sure how clear they will turn out on the site, i am uploading them from my phone where i cannot even see the full size image on the post. if you cannot read the label on either let me know and i will post to my website and send link when i get home.

 

[mitiempo]

Here it is again and easier to read.

As posted there may be some doubt about how AC Delco measures AH. In any case any true deep cycle battery will not list a CCA rating as it doesn't apply to any but a starting battery. 86 AH is very large for a group 24. I downloaded the entire AC Delco catalog and I couldn't find how they measure it. If you look at a Trojan's specs for a given deep cycle battery they state clearly the 20 hour rate as well as a few others. They do not show CCA ratings on a deep cycle battery.

Although common on many batteries not specifically designed for marine use the wingnuts are frowned upon by ABYC as you cannot get enough torque on them when tightening.