Deep cycle batteries

[scott_b]

Gday
Can anyone tell me what the differance is between a normal car battery and a deep cycle battery.
Thanks wamjam

[mulletguts]

A car battery is generally rated in CCA's (cold cranking amps) this means the battery is capable of providing a large amperage draw for a short period but is not able to supply a small current draw for long periods. A deep cycle battery is generally rated in A/H amp hours and this rating means the battery is capable of supplying small current draws for a long period of time e.g A6A/H deep cycle means it can provide a draw of 1 amp for 6 hours approx before recharging is required. deep cycle are generally gel or dry cell construction and a standard CCA rated battery is generally a wet cell or waterbased electrolyte (acid) Prices is also a major difference with deep cylcle being alot more expensive due too their construction and usage charecteristics Hope this helps you out.

[joeT]

ALL batteries are rated with a CCA and A/H.

CCA being the the cold cranking amps, which means how much amperage it can put out for a short burst when cold.

A/H is how much capacity the battery has to provide current over a period.

A deep cycle battery is one that is designed to withstand complete discharge and recharge cycles. If you did this with a normal car battery it would die in a very short period. However, all batteries will eventually die faster if you put it through many full discharge and recharge cycles.

'Ordinary' and deep cycle batteries come in a variety of CAA and A/H ratings.

[mulletguts]

Joe T your absolutely right about batteries being rated by both cca and a/h but generally an "ordinary" battery does not display the a/h rating as it is not designed for a constant current draw over a period.

[scott_b]

Thanks mulletguts & joe T
I understand A/hrs but whats the difference between the insides of the batteries . What do they do to make one have longer A/hrs and the other to have CCA.
wamjam

[joeT]

I'm no expert in batteries, but the differences would include thickness of plates, concentration/quantity of chemicals, and design. For example, a higher CCA can be achieved by greater surface area for the acid to react with the plates (assuming conventional wet acid battery).

[mulletguts]

normal batteries have thin sponge like plates which results in a greater surface area which as Joe T said gives a greater CCA rating Deep cycle have solid thick plates which lowers the surface area and the CCA rating the reason for the thick solid plates is that as a battery is charged and discharged the positive plate in the cell erodes or wears so a thicker plate can withstand many charge discharge cycles before plate failure occurs. hope that helps the chemicals are the same as they perform the same function in both types of batteries. Batteries come in flooded or wet electrolyte,Gelled electrolyte, and AGM Absorbed Glass Mat or dry electrolyte Hope this helps Cheers

[scott_b]

Thanks fellas.
Makes sence , happy to know their not the same battery with different price tags.
Thanks wamjam