4D AGM Deep Cycle Battery - 210 Ah, Marine Flag Terminals

12 volt LifeLine 4D AGM deep cycle batteries have a well-earned reputation for heavy-duty, high-quality construction and the ability to be discharged again and again without decreasing their amp-hour rating.
These 4D batteries (20.8"L x 8.7"W x 8.6"H ) are designed for deep cycle use in marine and RV applications.

All Lifeline deep-cycle batteries are hand-made in the USA. This 4D AGM marine battery is Coast Guard approved and have to meet demanding mil spec requirements, since they are used on numerous US Military vessels. They are designed to deliver industry leading reserve capacities and life-cycle capabilities. All Lifeline deep cycle batteries are backed by an exceptional 5 year warranty. (In the first year after purchase, if the battery fails due to manufacture defects, Lifeline warranty covers a free replacement.)

• Faster recharge, no current limitations with voltage regulated recharging
• Full recharge after 30 days storage in a full discharge condition (77°F rating)
• Less than 3% per month self discharge at 77°F (25°C); less at lower temperatures
• Sealed construction with absorbed electrolyte - no shipment restrictions, submersible without damage; install in any position; no need for watering
• Cell safety vent valves - pressure regulated, non-removable
• Rugged, non-marring polypropylene (copolymer) case/cover
• Safety - even during severe overcharge the Lifeline AGM battery produces less than 2% hydrogen gas (4.1% is required for flammability in air)
• Overall dimensions (including terminals): 20.8"L x 8.7"W x 8.6"H
• UL listed
• 4D Marine deep cycle battery also work for trolling motors and as rv batteries
• Made in the USA


Warning – Do not mix new and old batteries in a 4D AGM battery bank. Doing so will void the new battery's warranty, and it will not be returnable to Fisheries for a replacement or refund.

As batteries age they develop a resistance to charging, making them take longer to recharge. When new and old batteries are mixed, the increased charging required of the older batteries becomes the default regimen for the entire bank.
The result is that the newer batteries in the bank can be over-charged on a regular basis. This will damage the newer batteries and void their warranty.

Lifeline batteries in a deep cycle battery bank typically age (and begin to fail) as a group. If one of the batteries fails, the others are probably not be far behind. Don’t be tempted to replace only the failed battery.
Best practice is to always replace all the batteries in a bank at the same time.

How long do 4D AGM batteries last?

A well-maintained AGM battery typically has a lifespan of around three to four years, which is influenced by usage. The frequency of battery usage also impacts the battery's longevity.