Battery question

Photomom

We hooked up a charger to our T@B battery today in the garage. The battery still read 12.7v but when we examined the water levels before hooking it up we noted that the 3 cells on the + side were low and needed water. The 3 cells on the - side were at the normal level. 

Can someone explain?

ScottG

A flooded cell battery will off-gas a bit when charging, so a little water loss is considered normal. The important thing is to net let the level drop below the top of the plates, as that will promote sulfation and shorten the life of the battery.

I'm not sure if differential off-gassing among cells means anything. I've noticed that dying batteries "boil" more when being charged, so maybe it's a sign that those cells are a little more tired than the others. Either way, I'd just top 'em up (use distilled water) and go on my merry way. If your battery can still take and hold a charge, then it's still got life.

Photomom

Interestingly enough we checked the water level when we took the battery out 5 weeks ago and all the cells were at normal level. 

wizard1880

Both my nearly new golf cart batteries in the T@B, and a recently replaced battery in my car have also lost water on the cell(s) closest to the positive terminal.

I have no idea what this means, or if it's normal.  I've found no guidance from googling either...

ChanW

Yes, it's always been my experience that cells at one end of the battery use water faster than the other end.

Also I think that the more you charge the battery at a high rate, the more the electrolyte will boil, and lose water.

Photomom, are you using an 'external' charger to keep your battery topped off? Maybe it's over-charging? Or maybe you discharge your battery more than we do. Ours seldom needs water (annually at most). We only charge the battery with the Tab's system, and keep it plugged in pretty steadily.

DurangoTaB

Does anyone have experience with an AGM golf cart battery...so no cells to worry about?
e.g. http://www.samsclub.com/sams/duracell-agm-golf-car-battery-group-size-gc2agm/prod3870119.ip?mobiledetect=false

Photomom

ChanW said:

Yes, it's always been my experience that cells at one end of the battery use water faster than the other end.

Also I think that the more you charge the battery at a high rate, the more the electrolyte will boil, and lose water.

Photomom, are you using an 'external' charger to keep your battery topped off? Maybe it's over-charging? Or maybe you discharge your battery more than we do. Ours seldom needs water (annually at most). We only charge the battery with the Tab's system, and keep it plugged in pretty steadily.

The battery had been in the T@B until the end of October, maintained by plugging into the house or a campground every 2-3 weeks. Then we took the battery out, put it in the garage, and moved the trailer to my friend's barn for the winter. At that time we checked the water level, which was fine, and the voltage which was 12.7, fully charged.

We have some nasty weather coming so we got out today and hooked up the charger. Before we did we checked the voltage, still 12.7v, and checked the water level in the cells. We were surprised to see that the water level in 3 of the cells had dropped since the end of Oct with the battery just sitting there with no load.

Nomad

Don't know about anyone elses experience but I've looked in the holes and everything looked full but actually wasn't. Last time was helping a friend a few months back and was surprised that they actually took quite a bit of fluid even though they really didn't look low. Almost put the caps back on but decided to just pour a little in each - and I poured, and poured.

Sharon_is_SAM

Does it matter if you check the battery fluid after they have rested vs after recent discharging/charging?  Does the fluid expand when the battery is under load?

ColoradoJon

It is best to check the fluid level before charging but only so you are sure the water level has not dropped below the plates.  The water must be above the plates at all times.  The fluid can expand when it heats up so you don't want to overfill.  Fluid can evaporate over time, even when batteries are sitting idle as they are vented.  It all depends on atmospheric conditions.

My procedure: check fluid level, add water if necessary to bring fluid at least 1/8" to 1/4" above plates.  Charge.  After full charge cycle disconnect battery and let rest one hour.  Top off water.  Done.

@DurangoTab - AGM batteries are excellent, maintenance free batteries.  They do require a higher charge voltage and are more expensive than comparable flooded acid batteries, though.  The one you linked is 190 amps (20 hour rate).  And, AGM batteries can be laid on their side!

AldebaranJill

SAM said:

Does it matter if you check the battery fluid after they have rested vs after recent discharging/charging?  Does the fluid expand when the battery is under load?

It bubbles, gurgles, pops, hisses, outgasses, and makes all sorts of noises when charging, which is why @ColoradoJon says just to add enough water to cover exposed plates prior to charging, otherwise bubbling acid overflow. Once charging completed, then can add water to full mark line.

I have not heard sounds while discharging, and my battery manual states to fill water only after full charge, so must not expand or be too gurgly during discharge.

AldebaranJill

AGM batteries are excellent, maintenance free batteries.  They do require a higher charge voltage and are more expensive than comparable flooded acid batteries, though.  The one you linked is 190 amps (20 hour rate).  And, AGM batteries can be laid on their side!

For my application, Trojan Group 24 Deep Cycle AGM had lower AH capacity (76 vs 100) than Deep Cycle Flooded, but did have identical absorbtion charging spec range of 14.1V - 14.7V 

But if you want maintainance free, or to have them inside the cabin, or lay on side, they seem like a good option to consider, but there may be an AH capacity trade-off depending on brand. Of course if you have two 6V, you are swimming in capacity! If and when mine eventually goes, I would certainly consider two 6V under a seat if I could not fit outside. 

Carolyn

What does AGM mean?

ColoradoJon

AGM = Absorbent Glass Mat

For more info:  Click Me

Jltab

Anybody using a Deka Marine Master Deep Cycle Starting Battery. this is what I have when I bought my T@B, any trick and tips will be highly appreciated.

ColoradoJon

@jltab - I have no experience with that particular battery, but I do have two Deka 6V golf cart batteries hooked in series.  I've only had them since July and cannot comment on their durability or life expectancy.  They seem well made, are very heavy, and have a lot of capacity.  They were inexpensive, though, and have allowed me to test my dual battery setup on the cheap.

The marine battery you have is a hybrid - cross between 20 hour capacity and cold cranking amps.  For most people these batteries work well, especially if you have solar recharging.

Sorry I cannot say much about them.  They are new to me

Jltab

ColoradoJon said:

@jltab - I have no experience with that particular battery, but I do have two Deka 6V golf cart batteries hooked in series.  I've only had them since July and cannot comment on their durability or life expectancy.  They seem well made, are very heavy, and have a lot of capacity.  They were inexpensive, though, and have allowed me to test my dual battery setup on the cheap.

The marine battery you have is a hybrid - cross between 20 hour capacity and cold cranking amps.  For most people these batteries work well, especially if you have solar recharging.

Sorry I cannot say much about them.  They are new to me

Thanks @ColoradoJon, please share your experience with Deka 6V series setup later on.

j_ntabowners

Would anyone be willing to share a picture of their set up with a battery disconnect switch in place? I've found some helpful youtube videos on how to install one, but just wanted to see what other folks in this forum have set up.

Nomad

If you search for "cutoff" or something similarily relevent, there's several threads about cutoff switches with pics.

j_ntabowners

Thank you, will do

Vermonster

I don't have a pic of mine but it mounts directly on the battery terminal.  Install in literally minutes and works great.  Purchased at local auto parts

ScottG

You can also mount it inside near the converter, if you prefer.

j_ntabowners

hi Scott thank you for the photo, do you have a shot of how it hooks into your converter?  Sorry I'm such a visual guy I have to see it from several angles. 

ScottG

Here's a photo from the back. In summary, I cut the wire running from the battery to the converter, and crimped on a short extension and two appropriately sized ring terminals. The switch has a cover that fits over the terminal once everything is hooked up.

I got the idea for this installation from someone else on this forum, but I don't recall who. Feel free to PM me if you want more details.  

j_ntabowners

Vermonster said:

I don't have a pic of mine but it mounts directly on the battery terminal.  Install in literally minutes and works great.  Purchased at local auto parts

Thank you,  is it this one?

Vermonster

That's not the one but it's a similar idea.  Mounts on the negative terminal.  I'll get a pic tomorrow and post it

j_ntabowners

Thanks, sorry to be so annoying.   I appreciate the group's patience with this newbie.