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Warranty & Return Policy

In the unlikely event you are having an issue with one of our batteries we have designed and developed a clear warranty & return policy:

  • 5 Year Free Replacement Warranty (No Gimmicks!)

Chargers & Accessory Warranty

  •  All battery chargers (with exception of our new dynamic charger) and accessories from us come with a 1 year free full replacement of factory           defects. 

  •  The Dynamic Charger comes with a 3 year full free replcement of factory defects. 

     Warranty Registration

          You do not need to register for a warranty with Monster Marine Lithium Batteries, Inc.. You do need to keep your point of purchase                                documentations should you have issues and need to warranty your battery in the future.

  • For all returns or warranty claims contact

  • 30-day money back guarantee. Returns of undamaged batteries, chargers, or accessories may be issued full refunds less a 10% restocking fee.

  • Free lifetime technical support & free battery analysis.

  • Warranty only applies to original owner (non-transferable).

  • MML will email a shipping label if you have a defective battery so there is no shipping cost to customer on defective batteries. Customer will pay return shipping on returns if it is not a factory defect or if the customer wants the battery tested & inspection. MML with test and inspect the battery free of charge but customer is responsible for shipping cost. Please note some battery returns may require special documentation and packaging, and these instances will encounter extra fees. This is in order to correctly comply with lithium battery shipping regulations. For all return shipping we recommend using a local shipping service such as FedEx or UPS.

  • We do not have a charge cycle limitation within our 5 year warranty.

  • No part of our 5 year warranty is pro-rated.

  • In most cases battery problems can be solved via phone or email, if we determine the battery is defective we can get a replacement battery out to you in a matter of days NOT months.

  • If the battery issue can not be determined via phone or email we will have you send it in and once received testing only last a few days to determine what happened. If determined the issue was not caused by customer new battery will be sent out next day.

     Warranty Exclusions

  • Damage due to improper installation; (ex: overtightening terminal bolts, dropping battery to the point it causes the case to break open).

  • Damage due to improper operation.

  • Product that has been opened, modified or tampered with.

  • Tampering or removal of manufacture date codes.

  • Product that was used for applications other than which it was designed and intended for by the Manufacturer.

Lighter, Stronger, Longer!

Monster Marine Lithium Batteries, Inc.

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