Hooking a 24 and 27 Battery Together

[Kayamore]

Have a 24 battery in the boat to run the interior, can I hook it with a 27 in a series?

[Me-and-Boo]

Are you looking for 12 volts or 24 volts?
The 24 and 27 are the case size and capacity.

[sailorchic34]

In series for say 24 volts the two batteries (24 & 27) will only provide the group 24 capacity. Plus the group 27 will most likely never get a full charge which will effect battery life. In parallel, they work fine btw.

[Astral Blue]

If you connect batteries in series, you will double your voltage. Group 24 or group 27 are 12 volt batteries. If you connect them in series, you will have 24 volts. If your interior is a 24 volt system, then yes. Most systems are 12 volt. If you want a 12 volt system, you will need to connect them in parallel, not series.

[AlonzoWhite]

Originally Posted by Astral Blue

Group 24 or group 27 are 12 volt batteries.

What do you mean by this above sentence? Please be specific!!!

[cal40john]

Originally Posted by AlonzoWhite

What do you mean by this above sentence? Please be specific!!!

Group number refers to the physical dimensions of a 12 volt battery.

Example:
GRP Length Width Heighth
24 10 1/4 6 13/16 8 7/8

From table of battery sizes:
BCI Battery Group Size Chart

In general bigger physical dimensions means a battery that has more capacity. One measure of which is in amp-hours.

Batteries in series you add volts, batteries in parallel you add capacity.
2 12 volt batteries in series equals 24 volts, which is not good if your boat is 12 volts.

[Astral Blue]

Here is an explanation:

Batteries come in all different sizes. Many have "group" sizes, which is based upon the physical size and terminal placement. It is NOT a measure of battery capacity. Typical BCI codes are group U1, 24, 27, and 31. Industrial batteries are usually designated by a part number such as "FS" for floor sweeper, or "GC" for golf cart. Many batteries follow no particular code, and are just manufacturers part numbers. Other standard size codes are 4D & 8D, large industrial batteries, commonly used in solar electric systems.
Some common battery size codes used are: (ratings are approximate)

U1 34 to 40 Amp hours 12 volts Group 24 70-85 Amp hours 12 volts Group 27 85-105 Amp hours 12 volts Group 31 95-125 Amp hours 12 volts 4-D 180-215 Amp hours 12 volts 8-D 225-255 Amp hours 12 volts Golf Cart & T-105 180 to 225 Amp hours 6 volts L-16, L16HC etc. 340 to 415 Amp hours 6 volts
To view the entire document, click here.

[bruce smith]

I believe it is wise when "marrying" batteries, to buy them at the same time, and to be the same battery size. Two on the same switch setting, parallel or series.

[sailinglegend]

Originally Posted by bruce smith

I believe it is wise when "marrying" batteries, to buy them at the same time, and to be the same battery size. Two on the same switch setting, parallel or series.

Recent research by Lifeline Batteries has proved that a bank can be made up of different capacities and that the life of the batteries was not compromised, as long as they are all the same make and the same age. This goes against most previous guidelines, but Sabre yachts, which use Lifeline AGMs, regular ship with different sized batteries to be able to get the maximum capacity from all the available space.

[FlyingCloud1937]

Originally Posted by sailinglegend

Recent research by Lifeline Batteries has proved that a bank can be made up of different capacities and that the life of the batteries was not compromised, as long as they are all the same make and the same age. This goes against most previous guidelines, but Sabre yachts, which use Lifeline AGMs, regular ship with different sized batteries to be able to get the maximum capacity from all the available space.

I for one would like to see the study, as well as the factors that were used in saying yes.

Is Sabre Yachts, driving the truck?

Why would not a battery in a Sabre be subject to the same laws of physics.

Lead Acid batteries have been the same for almost 100 years, chemistry is chemistry.

I know that a battery will only accept as much current in relation to resistance....but that is not what kills bats that are over charged...high voltage is. It's the number one cause of bats that are murdered.

Right behind chronic under-charging.

I'm holding my breath...but not for very long.

Lloyd

[sailinglegend]

Originally Posted by FlyingCloud1937

I for one would like to see the study, as well as the factors that were used in saying yes..........

I too had my doubts - so see this discussion from Morgan Cloud's website:

Mixing Battery Sizes In One Bank On A Boat

[FlyingCloud1937]

Originally Posted by sailinglegend

I too had my doubts - so see this discussion from Morgan Cloud's website:

Mixing Battery Sizes In One Bank On A Boat

MORGANS CLOUD...SEEMS TO BE AN OPINION BASED ON HIS UNDERSTANDING OF HOW THINGS WORK.

Not really a study, nor would it qualify as scientific, 1 sailors opinion, is in most cases more dangerous then, another sailors guess.

Especially if it is espoused with authority.

L

[sailinglegend]

Originally Posted by FlyingCloud1937

.....1 sailors opinion, is in most cases more dangerous then, another sailors guess..........

There are 12 other comments there - I suggest you read them too!

[FlyingCloud1937]

Originally Posted by FlyingCloud1937

MORGANS CLOUD...SEEMS TO BE AN OPINION BASED ON HIS UNDERSTANDING OF HOW THINGS WORK.

Not really a study, nor would it qualify as scientific, 1 sailors opinion, is in most cases more dangerous then, another sailors guess.

Especially if it is espoused with authority.

L

a quick ad words check also shows that MC has an income stream from their blog.

[mitiempo]

No they don't. Scroll down to finances.
The Future of AAC, morganscloud.com—Part 1