About

Someone whose house bank or trolling-motor battery has died is trying to answer one question: what replaces this, and will it actually fit? Today that takes a manufacturer page that lists no part number, a retailer listing that says “compatible” without saying on what basis, a forum thread from 2021, and a recall database that is hard to search by model.

This site puts those in one place, per model, with the source for every figure. Not a review site and not a shop — a reference you can check.

We do not manufacture, sell, distribute, install, repair, test or certify anything. We are not a laboratory, a certification body, an insurer or a safety authority, and we are not affiliated with or authorised by any manufacturer, brand or regulator named here.

We never say a battery is safe, and we never say a battery is guaranteed to fit. What we publish is what a named source says, with the source attached, so you can judge it yourself. Where the evidence is weak we say so rather than rounding it up — see Methodology.

DC Power Index is a small independent project. A legal operating entity is being formed and will be named here once it exists — we would rather say that plainly than print a placeholder. Correspondence is handled through the contact page in the meantime.

It is not a large team, and that is relevant to how you should read the site: coverage grows one manufacturer at a time, because every figure is read from a real document before it is published. Pages appear when they are ready rather than all at once.

If a figure here is wrong, tell us and we will check it against the source and fix it. Manufacturers, retailers and owners are all welcome to write; an official document attached to an email is the most useful thing you can send, and it is why corrections arrive by email rather than through a form.

If something here is dangerous — a specification that could lead someone to fit the wrong battery — say so and it will be treated ahead of everything else. See Contact.

The catalogue covers deep-cycle batteries and the two things that relate to them: what houses them — boats, motorhomes, trailers, camper vans, overland vehicles, cabins — and what draws from them, such as trolling motors, outboards, inverters, refrigeration and winches. Along with the chargers and solar controllers that go with them, and safety records from the regulators of the United States, United Kingdom, European Union, Australia, Canada and France.

It is not complete and does not claim to be. Where a model is absent, that means we have not read it yet, not that it does not exist.