Batteries

[cruzkid]

I am going to buy new house batteries. I now have 2 12 volt batteries. Will I be better off putting back 2 6 volt batteries or 4 6volt batteries or just replacing what I have? I plan on doing a lot of boon docking.

[Dale_Traveling]

This is getting better than a tire pressure thread. Think I'll make some popcorn.

[Flanz]

1BryNelson wrote:
Do not just replace 6V w/ 12V. There are more adjustments to be made to your charging system.

Such as....? There is no problem with replacing 12v with 2 6v. Please explain?

-paul

[Matt_Colie]

If you can carry an 8D, I will try real hard to not get in a fight with you. The 8Ds I put in the performance cruisers (read retired racing racing sloop) tip our scale a 168#. I haven't been able to carry one of those for years. I can still lift and move a 4D (136#) but carrying it just isn't going to happen. When I explain to an owner that installing a 8D requires rigging to lift it with the main halyard or the like and service at a mooring is impractical, we often back off to GC2 or T105. We do very little of this business since the depression started, but I may be coming back.

Matt

[wa8yxm]

A lot depends on the 12 volt batteries.. One of the issues I have is folks say "12 volt battery" but that is not really enough. here is why

These are 12 volt batteries

Group 24 About 77 Amp hours (One brand is 76)
Group 27, about 95
Group 29, about 105
Group 31 about 130
4D around 200
8D around 260

Now all the above I can pick up and carry at least one.. I have used much larger 12 volt batteries and If I had the CCC I might well get one.. For example for ARRL Field Day one year I borrowed a battery from a battery rebuilder.. This one was big enough that they banded it to a pallet and set it on my rented trailer using a fork lift.. Oh, I might add, an identical battery powered the fork lift.

I also have a much smaller one (Single digit amp hour) I use to run a fan or blower on occasion.

Thus "12 volt battery" without a size reference is ... Kind of useless.


SIX volt batteries: Now here too there are different sizes but

The common GC-2 is 230 amp hours, A Deka G-10 (GC-1) is 210 amp hours and the big trojan's I think 250 amp hours.

So those are all close in size.

Now you have the info to do the math.

Some folks yammer "You need to upgrade your converter" not true.

But the larger the battery bank (Amp hours) the longer to re-charge.. BUT, the slower the recharge (The longer it takes) in most cases the longer the overall battery life.. There is one exception I know of

Lifeline AGM.. and for that one you will need to read the web page
But they recommend a much higher initial charge current than any other battery I have researched including MK/DEKA AGMs. (East Penn battery Company) WHich I have owned and do not recommend.

[pianotuna]

Any solar is a good thing. More solar is a better thing.

[pianotuna]

Hi OhhWell,

Voltage drop becomes an issue with six volt jars because of the thicker plates. Batteries are tested at 25 amps draw. Four six volt jars do ok up to about 150 amps of draw--but would still exhibit more than twice the voltage drop of 4 similarly sized 12 volt jars.

I push my inverter hard--and am moving up to a 3000 watt. That will represent a load of 300 amps if it going "flat out".

On the reliability side of the coin, there are twice as many cells in four 12 volt jars--so the chances of a catastrophic failure are doubled.

What works well for me, won't necessary work well for another camper.

OhhWell wrote:


Two 12v batteries in parallel do provide more instant amp draw (NOT necessarily CAPACITY) so I guess that would definitely be a major consideration if you have a massive inverter and only room for 2 batteries. Is the Amp drain level that small on 6v cells that the usual 2000-3000 Watt inverter would cause a problem?

some 12v cells do have high capacity but it is almost always cheaper to get a comparable amount of Ah capacity by going the 6v route.

I have no solar save a little 5W trickle maintainer panel built into my A/C shroud so... am I a sinner?

[OhhWell]

1BryNelson wrote:
See this is why U need to back up. 2 6v do = 12v. But the 6v have more amp hours. I just put 480 watts of solar panels and 440 amp hrs of battery storage in 6v batteries. If Ur planning on true boondocking it's power consumption vs ability 2 store.

I'm sorry but I can't completely understand either of your posts. The OP is asking for advice, why does he need to back up?

To the OP, if you have the room, 4 6v cells wired appropriately is usually the most economical way to get the most capacity and still have a good sustained AMP output ability.

[OhhWell]

pianotuna wrote:
Hi,

The real answer is "it depends".

For example, if a large inverter is in use, then 12 volt jars may work better.

Twin six volt jars are not always a higher number of amp-hours than twin 12 volt jars.

Look at amp-hour cost per year of operation.

Wiring in a balanced manner is important.

Solar has become so cheap it is almost a sin to not have at least 60 watts per 100 amp-hours of storage.

In short, battery bank design needs to "fit" the camping style.

Two 12v batteries in parallel do provide more instant amp draw (NOT necessarily CAPACITY) so I guess that would definitely be a major consideration if you have a massive inverter and only room for 2 batteries. Is the Amp drain level that small on 6v cells that the usual 2000-3000 Watt inverter would cause a problem?

some 12v cells do have high capacity but it is almost always cheaper to get a comparable amount of Ah capacity by going the 6v route.

I have no solar save a little 5W trickle maintainer panel built into my A/C shroud so... am I a sinner?

[pianotuna]

Hi,

The real answer is "it depends".

For example, if a large inverter is in use, then 12 volt jars may work better.

Twin six volt jars are not always a higher number of amp-hours than twin 12 volt jars.

Look at amp-hour cost per year of operation.

Wiring in a balanced manner is important.

Solar has become so cheap it is almost a sin to not have at least 60 watts per 100 amp-hours of storage.

In short, battery bank design needs to "fit" the camping style.

[1BryNelson]

See this is why U need to back up. 2 6v do = 12v. But the 6v have more amp hours. I just put 480 watts of solar panels and 440 amp hrs of battery storage in 6v batteries. If Ur planning on true boondocking it's power consumption vs ability 2 store.

[Gjac]

How many amp hrs do you use a day? Do you watch a lot of TV? Internet? What type of MH do you own? I dry camp 90% of the time with 2 6 v Sam's Club batteries and can go a week before they reach 50% SOC. By then I need water anyways unless I am very careful. I don't watch TV so only lights and water pump. If I stay longer I am always looking for ways to exercise the genset anyways. So I depends on how you will camp.

[2oldman]

1BryNelson wrote:
Do not just replace 6V w/ 12V..

He's doing the opposite.

[wny_pat1]

1BryNelson wrote:
Do not just replace 6V w/ 12V. There are more adjustments to be made to your charging system.

Why? Two 6V equals 12V and charge just like a 12 volt. Just a matter of wiring properly!

[1BryNelson]

Do not just replace 6V w/ 12V. There are more adjustments to be made to your charging system.