What's the big deal with 6v batteries?

[Vagabound]

As I've been reading about solar and batteries over the last year, I've noticed that more than a few people who I would consider "very serious 12v energy people" tend to go for 6v batteries.  Usually golf cart batteries.  I cannot put my finger on the reason.

I understand that connecting them together in the right way gives you 12v, but why bother with all of that instead of just buying a battery that is 12v in the beginning?  In other words, why are the "cool kids" buying 6v batteries?  And what are the pros (and cons if any) of that battery type?

 

[NickTheoBennett]

It might be just because they're cheaper than an equivalent 12v deep cycle battery. I got my 205ah set of Interstate branded golf cart batteries at Costco for somewhere around $180 and Costco will accept a return on them within 1 year for any reason at all, so I have that option if they end up crapping out too early.

 

[frater secessus]

Pro: The 6v golf cart batts have increased capacity and longevity. Probably cheaper in the long run.

Con: Short term expense. Physically taller so may not fit in all bays. Requires serial cabling to get 12v.

 

[ZoNiE]

In a Nutshell:

1. Larger cells and larger plates, means deeper discharge capability and longer life.
2. A 6-volt battery has three 2.4-Volt (nominal) cells. A 12-volt battery in the same size case has six 2.4-volt cells, so the cells are half the size.
3. If you put two 6-volt batteries in series to make one 12-volt bank, a weak cell in one of them will not affect the other battery, just reduce the overall voltage.
4. If you put two 12-volt batteries in parallel, a bad cell in one will not only reduce the overall voltage, but it will affect the charge capability of both batteries.
5. 6-volt batteries are less likely to be stolen by thieves wanting to make a quick buck. They cannot be used in cars. Two thieves tried to steal my trailer batteries in my driveway. I surmise that They realized that when they cut the center wire, they were 6-volt, so they left them behind. The cops caught them anyway with a car full of batteries.

If you only have room for one battery, 12V is the way to go, but if you want 225Ah of storage and have room, go with the 6-V GCC's. They are the same basic size as a group 24 but taller.

 

[SternWake]

Very few wet/ flooded 12 v batteries are actually deep cycle. They are a hybrid more closely related to a starting battery t han a true deep cycle.

An equal capacity, in the same usage, 6v Gc2 batteries will last twice as many deep cycles.

so its not the cool kids. It is the wise nerds making the golf cart battery choice. As t hey are actual deep cycle batteries, not some starting battery hybrid with a fancy sticker.

agm batteries blur the line between starting and deep cycle.

 

[Vagabound]

In a Nutshell:

...

2. A 6-volt battery has three 2.4-Volt (nominal) cells. A 12-volt battery in the same size case has six 2.4-volt cells, so the cells are half the size.

I REALLY like the size of your nutshell!

Your Item # 2:  So what?

Thanks for the concise, yet highly informative list so far.

Vagabound

 

[Vagabound]

...  so its not the cool kids. It is the wise nerds making the golf cart battery  choice.  ...

In this case, cool kids = wise nerds = people doing the latest, greatest thing.  That's what I meant.  I was just trying to be funny.

Thanks for explaining.

Vagabound

 

[Spaceman Spiff]

Your Item # 2:  So what?

from ZoNiE:  "[font=Verdana, Arial, sans-serif]2.  [/font][font=Verdana, Arial, sans-serif]A 6-volt battery has three 2.4-Volt (nominal) cells. A 12-volt battery in the same size case has six 2.4-volt cells, so the cells are half the size."[/font]

Bigger cells = bigger plates, more electrolyte = more capacity.

Add to the list:
6.  6V, deep cycle batteries each have 1/2 the weight of a comparable 12V deep cycle battery:  6V, 200AH battery = ~60 lbs; 12V, 200AH battery = ~120 lbs.  I'd rather lift 60 lbs twice than 120 lbs once.  Becomes very important if your battery box is in a hard to reach place.
7.  6V golf cart batteries are easy to find (I got mine at Sam's Club).  True deep cycle 12V batteries, not so much.

 -- Spiff

 

[ZoNiE]

I REALLY like the size of your nutshell!

Your Item # 2:  So what?

Thanks for the concise, yet highly informative list so far.

Vagabound

So 2.4V cell in the 6V battery is twice the size as the 2.4V cell in the 12V battery, so it has double the capacity, and lasts longer both charge-wise and life-wise. That's what.

 

[ZoNiE]

Wait, aren't Nerds the cool kids?
???

 

[WheelEstate USA]

When we had a single 12V "deep cycle" marine, we used most of what it had stored each night. Upgrading to 6V x 2 gives way more storage (power) than we can use on a nightly basis.
That came in real handy during monsoons while in the forest. Some days no sun and others with only a couple hours. We were fine with cridge and even a few hours of TV in the eveing.
 
Now, to start on a budget, a 12 V "deep cycle" from Wally's and a 100 watt solar kit will get you started with a basic system...you can always upgrade over time.

 

[rvpopeye]

Quick answer................
It's all about the lead.
Bring a scale and weigh the batteries , heaviest wins.

 

[highdesertranger]

all good points that have been put forth. I will add, we want deep cycle batteries for our house batteries. 6v deep cycle batteries are easy to find and cheaper then their 12v cousins. 12v deep cycles are hard to find and expensive. highdesertranger

 

[ccbreder]

Keep in mind that all the 12 volt batteries you see in the common battery stores that are labeled marine "deep cycle" are not true deep cycle. All Golf Cart batteries you see in the common battery store are true deep cycle.

 

[GotSmart]

The testosterone on this thread is making me dizzy.  A deep philosophical study of the 2.4v cell agreeing that, Bigger is Better.   :dodgy:

MORE POWER!  

 

[Optimistic Paranoid]

MORE POWER! 

"Nine Rings were gifted to the race of men, who above all else desire POWER"

 

[NickTheoBennett]

"Nine Rings were gifted to the race of men, who above all else desire POWER"

One Ring to rule them all? LiFePO4, for those who don't want to click.  Not an option I considered because of the price tag, but they do seem pretty neat.

 

[anewbiewannabe]

The testosterone on this thread is making me dizzy.  A deep philosophical study of the 2.4v cell agreeing that, Bigger is Better.   :dodgy:

I'm so not touching that one! ROFLMAO!!!!

I love the LOTRs references too!

 

[blars]

Lead-acid cells are 2.1v nominal fully charged, six cells for a 12.6v nominal pack. LiFePO4 cells are 3.3v fully charged, four cells for a 13.2v nominal pack. (They are sometimes called 3.2v, but that is near fully discharged -- much flatter discharge over the usable range than lead-acid.)

 

[DannyB1954]

Thick plates vs thin. The thinner the plates are, the more energy you can get out quickly, (starting). Thicker plates are better for long term low battery drain, ( less internal damage). Deep cycle 6 volt batteries use thicker plates. My experience is that a bad 6 volt battery can take out the other 6v battery. If nothing else it can prohibit it from charging. In a series circuit if there is no current flow through one battery, there will be no current flow in the other. If one battery develops an internal short, it can drain the other battery. A dead battery left dead will ruin it.

When using two 6 volts in series, I have never had to replace just one of the batteries. Maybe if I were to check them everyday, I could save one of them. Having one new battery in series with an old battery is not a great idea anyway.