Interstate Batteries Marine/RV Battery 12V 100Ah 825CCA Dual Purpose Power Pure Lead AGM RV & Marine Starting Replacement Battery (Group Size 31M) Boats, RV's (8-31MAGMDC / 31M-AGM-A)

High quality battery that has never left me stranded. Even after leaving my boat moored for an extended period of time, cranked over with all the expected power. I guess the best compliment to the battery is after installing it, I never had to think about it again.

Great battery!!!!!

After 12+ years, I finally replaced my sump pump backup battery setup and upgraded it properly — and I’m really glad I did. I was debating one expensive battery ( also group 31) ..but bought 2 of these for less than the cost of one. I’m running a 3/4 HP sump pump with about 7 ft of vertical head, and the discharge line slopes downward after that. So the pump isn’t under extreme load, but reliability during outages is critical for me. I paired two Group 31 AGM batteries (in parallel) with my Tripp Lite APS750 inverter/charger, and the difference is noticeable right away. Startup is smooth, voltage stays stable, and I now have significantly more runtime during outages. For wiring, I connected the batteries positive-to-positive and negative-to-negative, and then connected the inverter across the two batteries (positive on one battery and negative on the other). This helps balance the load and ensures both batteries are used evenly. A nice bonus is that I’m also able to keep my modem and WiFi running off the same setup during a power failure, which makes a big difference during storms. A few things I learned that might help others: - Don’t rely on an old battery just because it hasn’t been used much — mine was over 10 years old and definitely due for replacement. - Adding a second battery in parallel is a much better upgrade than buying a single expensive “premium” battery. - Use proper short, thick cables and connect the batteries cleanly — it really matters for performance. - Test the system after setup by simulating a power outage. Overall, this setup gives me a lot more confidence heading into heavy rain or storm season. Simple upgrade, but a huge improvement in peace of mind.

Fabulous batteries for my boat. Packed and shipped extraordinarily good!

Great value for an excellent battery. Performs well.

The battery works well. It arrived with an 80% charge. Mine is rated 825 CCA. I charged it fully, and it tested healthy and over 950 CCA. It was purchased September 2025. It has a shipping date on the carton (from Interstate to Amazon) of August 2025. It has a manufacture date on the battery of March 2025. Just an FYI to give you an idea about battery age and how long it's been in storage before you buy. Finally, the model I received should have a 36-month free replacement warranty per Interstate warranry for batteries purchased March 2025 or later, as well as per the Amazon listing/description. The battery itself claims 24-month free replacement. Not sure what's up with that. We will see.

I immediately tested this battery since the last one was DOA.This one tested and showed 1153 CCA.Also was 100% charged

Durable