battery maintenance

Aug 17, 2013
1,309
Pearson P30 202 Ottawa
ok time for a simple question, I know you have to add water to general batteries, but do you have to add some to deep cycle batteries?
I forgot to pull the battery from the boat before winter and I've started to charge her up and after a while it started making some weird noises (bubbling noise)
 
Aug 2, 2009
651
Catalina 315 Muskegon
The answer is... probably. Many "deep cycle" batteries are conventional flooded lead acid batteries, and require monitoring of their fluid levels and occasional topping off with distilled water.

If you have caps that pry off the top of your batteries and there's liquid inside, you'll need to add distilled water when they get low. Shame on you :biggrin:for not keeping an eye on your batteries, but going forward, you'll know to keep some distilled water onboard and add occasionally. Your batteries will thank you for it.
 
Last edited:
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
If they say maintenance free then no water required. If they have caps then yes you need to monitor water levels.
 
Nov 13, 2013
723
Catalina 34 Tacoma
Given the chose, why would one choose a non-maintenance free? Are their amp hr ratings lower?
 
Feb 26, 2004
23,343
Catalina 34 224 Maple Bay, BC, Canada
Given the chose, why would one choose a non-maintenance free? Are their amp hr ratings lower?
It's not only the ah ratings. Sealed batteries are not true deep cycle batteries. That simple.
 
May 24, 2004
7,213
CC 30 South Florida
Learn something every day. What is a true deep cycle battery? I was recently told by a battery guy that true deep cycle batteries are too sensitive to movement to be used in a moving vehicle application. He indicated they excel for storage of power in backup applications and even in off the grid solar panel home applications but they like to sit still in a solid platform. He indicated that the type of batteries used in Golf carts and marine applications are a form of semi- true deep cycle adapted for performance under motion. These sounds to me like semantics as we consider deep cycle marine batteries as true deep cycles but I remember someone a while back that had thought he hit the mother load as he found some used but lightly cycled batteries that had been used for computer back up at a real good price. I don't know if he purchased some or not but it might just be a good idea to stay away from those. I do choose batteries that are designated for marine or golf cart applications. Most if not all "maintenance free" deep cycles I have seen are AGM. It does seem that most regular wet cell deep cycles will have caps and require periodic maintenance. just a tidbit of information, nothing of real importance for us, but something I had not heard before.
 
Aug 2, 2009
651
Catalina 315 Muskegon
If you want to learn more about batteries, I highly recommend anything MaineSail (forum member here and on Sailnet) has to say about them. Depending on how much you care to delve into his information, you can gain some excellent practical knowledge without making your head spin too badly.
 
Feb 26, 2004
23,343
Catalina 34 224 Maple Bay, BC, Canada
Nov 13, 2013
723
Catalina 34 Tacoma
I suppose if deep cycle isn't an issue, say as in a starting battery, maintenance fee would be the preferred choice.
 
Feb 26, 2004
23,343
Catalina 34 224 Maple Bay, BC, Canada
I suppose if deep cycle isn't an issue, say as in a starting battery, maintenance fee would be the preferred choice.
It's just another choice. You could also use a deep cycle as a reserve bank, too.
 

RoyS

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Jun 3, 2012
1,742
Hunter 33 Steamboat Wharf, Hull, MA
Wet batteries can freeze if discharged. Freezing will cause internal damage. Proceed with caution.
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Wet batteries can freeze if discharged. Freezing will cause internal damage. Proceed with caution.
Only if left discharged or unless you live in Fairbanks where it regularly gets to -60F or colder.

AGM & GEL batteries can also freeze and be damaged. The idea that AGM or GEL can't freeze and be damaged, if allowed to become discharged, is really quite untrue.

Any lead battery should always be left 100% charged and 100% disconnected in cold temps to minimize any parasitic draws and this is regardless of whether or not you have AGM, GEL or Flooded lead acid batteries..
 
Aug 2, 2009
651
Catalina 315 Muskegon
I suppose if deep cycle isn't an issue, say as in a starting battery, maintenance fee would be the preferred choice.
You may be taking "maintenance free" too literally. At the very least, the term is an exaggeration. Battery manufacturers and retailers make a lot of claims, and most of them are suspect.

One thing you can be sure of with a maintenance free battery is that it cannot be maintained. You won't find them on my boat.
 
May 24, 2004
7,213
CC 30 South Florida
Maintenance free batteries also come in a vented and non vented types. I guess the vented allow a small amount of charging gases to escape and the non vented.....
 

capta

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Jun 4, 2009
5,072
Pearson 530 Admiralty Bay, Bequia SVG
Learn something every day. What is a true deep cycle battery? I was recently told by a battery guy that true deep cycle batteries are too sensitive to movement to be used in a moving vehicle application.
Though I'm not positive, I believe deep cycle batteries were primarily developed or at least first commonly used in golf cart, fork lift, etc. applications. If they are "too sensitive to movement to be used in a moving vehicle application" then one would think that they were not very suitable for golf carts or fork lifts. Whoever told you that they were not suitable "to be used in a moving vehicle application" is someone who knows nothing about deep cycle batteries at the very least and would probably not be a good source for any marine related information.
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Though I'm not positive, I believe deep cycle batteries were primarily developed or at least first commonly used in golf cart, fork lift, etc. applications. If they are "too sensitive to movement to be used in a moving vehicle application" then one would think that they were not very suitable for golf carts or fork lifts. Whoever told you that they were not suitable "to be used in a moving vehicle application" is someone who knows nothing about deep cycle batteries at the very least and would probably not be a good source for any marine related information.

There are some deep cycle "stationary" batteries that are not designed for moving vehicles but these are usually massive tubular batteries.

There are many dep cycle batteries designed for use in motive applications from 2V cells & 6Vbatteries to 12V batteries..

These are stationary deep cycle...

 
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capta

.
Jun 4, 2009
5,072
Pearson 530 Admiralty Bay, Bequia SVG
There are some deep cycle "stationary" batteries that are not designed for moving vehicles but these are usually massive tubular batteries.

There are many dep cycle batteries designed for use in motive applications from 2V cells & 6Vbatteries to 12V batteries..

These are stationary deep cycle...

I stand corrected, again.
 
Aug 17, 2013
1,309
Pearson P30 202 Ottawa
I finally found where to add water to my battery, thanks everyone for the help.
I added some distilled water.
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
If you have allowed the water level drop so that you can see the lead plates for too long
than your have shorten their life for sure and maybe pretty soon will need to be replaced soon.
I have 4-6 volt Trojan T-105's and they are really great batteries if you take care of them
and I used them pretty hard and they are really doing a great job but check the water level
and don't let them get below 50% too