Deep Cycle Batteries - Flooded or SealedA common Deep Cycle battery question is whether to go for Flooded (or Wet lead acid) batteries or the newer Sealed (Gel or Absorbed Glass Matt (AGM)) types. Its not a simple answer but some of the pro's and cons are listed below.
If you have other questions then feel free to drop in for a chat, or call/email us. We have good parking at the Stores and we can size up & test batteries with you to suit your needs.
Flooded versus Sealed
Lead-Acid versus GEL/AGM
AGM versus GEL
Some more information on the 3 types of Fully Sealed (aka Dry Cell) batteries follows. True Deep Cycle Sealed batteries come in 3 main construction types, which in order of increasing price (quality and all other things being equal) are as follows;
Sealed Lead Acid (SLA).
Sometimes called Valve Regulated Lead Acid (VRLA) because they contain a pressure valve which acts as a safety device to vent the battery under fault conditions (severe overcharging or internal faults). Often designed for non-cyclic applications (float or standby), SLA is now considered a slightly old-fashioned term but like "gell cell" and others its still in use.
Sealed Lead Acid deep cycle batteries work reasonably well and are fully sealed so can be used safely inside Motorhomes / Boat cabins etc. Often also used as a reasonably priced option for Golf carts (although they can often perform poorly in that application - Gel batteries are a better solution).
Overall performance is very similar to the non-sealed (wet) Lead Acid batteries, and in particular note that they are charge rate-limited and will only accept current from a charger at a modest rate, regardless of the output of the charger. This contrasts with many AGM / GEL batteries, as discussed below.
Absorbed Glass Mat (AGM).
AGM Deep Cycle batteries provide much better performance than traditional Lead Acid batteries, with lower internal resistance allowing for much faster charging and better performance under heavy load conditions.
The electrolyte is wicked up into a glass matt internally so it can never spill which is also an advantage. AGM batteries are also better in extreme cold conditions than other Deep Cycle types. Feedback from the batteries sent on the 2009 Mawson's huts expedition to Antarctica (which were Ultimate UL120 AGM batteries) was particularly good, although generally in Australia extreme cold is not a major consideration. We stock and strongly recommend the USA-made Lifeline Deep Cycle range, as well as the Ultimate UL Battery Range and the Ritar AGM range.
We also stock the USA-made Optima range of spiral wound AGM batteries which are incredibly tough due to their plates being tightly wound around a circular core. Many Optima batteries have Deep Cycling or Dual (starting and Cycling) capabilities. Although they tend to have a lower Amp-Hour rating for a given size than the more traditional constructions we would still recommend them wherever vibration is likely to be an issue (such as many 4WD destinations in Australia) and for high performance applications - especially under vehicle bonnets where they can cope with the heat better than many other sealed AGM types because of their case construction.
In Gel batteries the electrolyte is mixed into a paste, which gives similar advantages to AGM batteries (i.e. non-spillable and lower internal resistance leading to better performance than traditional Lead Acid).
Although you should never flatten Deep Cycle batteries (it drastically reduces their life span), if you do have a situation where regular flattening is almost unavoidable (e.g. Golf buggies with a small battery space) then a good quality Gel battery will tolerate this better than any other type of Deep Cycle battery. Note the term "good quality Gel" as many cheaper brands are poorly mixed and perform badly in Australian conditions.
The downside with Gel batteries is that they require a lower charging voltage than standard Lead Acid or AGM types (typically 14.1V at room temperature). Gel batteries also tend to be more expensive for a given capacity than other sealed types. We stock the USA made GEL-TECH range and the German Sonnenschein brands, both of which are excellent.
Charging & InstallationFollow this link for more help and information on installing and charging your deep cycle battery.
Also we would be happy to provide advice on the right charger for your particular requirements. Some of our wide selection of Battery Chargers are now available online.
We also have a wide variety of fixed and folding Solar panels with associated regulators / charge controllers.