Marine Deep Cycle Battery Recommendations.
Traditional Access Style (Flooded/Wet Lead-Acid) Marine Batteries.
If you want a good value and proven long-lasting marine starting battery (which also has cycling capability for on-board electrics), then we would go for the Century Marine Pro Range. You should also consider Trojan Batteries and the surprisingly good value E-Nex range from South Korea.
Absorbed Glass Matt (AGM) Marine Batteries.
We offer a huge choice in AGM, depending on your budget and requirements. At the top the USA Lifeline range is probably the best AGM Deep Cycle battery you can buy in traditional format (i.e. vertical plates and a rectangular case). Super fast charging and unbeatable lifecycle, all with a 5 year Warranty.
You could also consider the Deka range at the high-end, or the Optima range. With unbeatable vibration resistance given by their spiral wound plate design, the Optima Blue Top batteries are very powerful and fast to recharge from flat. They hold their charge very well and the only potential weak point is a lower Amp-Hour rating for the battery size than some other AGM types with the same footprint. The D31M gives 75Ah with 900 Cold Cranking Amps.
In AGM technology we also stock batteries from Full River, Century and Ritar. All are suitable for Marine use and many in sizes from below 80Ah to over 200 Amp-Hour.
GEL Deep Cycle Marine Batteries:
If you are replacing GEL batteries and have a GEL compatible charging system in place then we would recommend the USA GEL-TECH Deep Cycle battery range for Marine use. Be aware though that they do need GEL charging - i.e. lower voltage than Flooded or AGM. Other GEL batteries are available on request but we have had good feedback on the GEL-TECH range so we stock it mainly along with the German Sonnenschein range. We have yet to find a Chinese manufactured GEL battery with the right quality for Marine use. AGM processes are fine, but GEL is harder to make!
For internal use (under seats etc.) you need to use a sealed battery that will not normally give off any gas while charging. Absorbed Glass Mat (AGM), Gel and Maintenance Free (Sealed - valve regulated) are good choices here. Note that batteries should never be put in a fully sealed box, there should always be some level of ventilation to allow for fault conditions or overcharging.
Ultimately the available space, charging solution and value for money will determine the best choice and we would be happy to advise further if you are in doubt. Battery testing and condition reports are also available, as is marine grade battery cabling and crimping, plus terminals and a wide range of Marine Grade Battery Chargers from CTEK (the M-Series), and also from Projecta, Victron and Matson.
We also sell Solar Panels and Regulators from the smallest (for trickle charging) up to 200Watt plus to properly charge your batteries while you sail.