31HD 12V Battery Replacement for Interstate 31-MHD | Group 31 Heavy Duty

Description

31HD 12 Volt Battery — Replacement for Interstate 31-MHD

If you’re replacing an Interstate 31-MHD, a properly matched 31HD 12V heavy-duty Group 31 battery is often a suitable replacement class—as long as the physical fit and terminals match your installation.

Critical Fitment Checklist (Do This First)

• Group Size: Confirm your existing battery is a Group 31 variant (many Interstate 31-MHD are Group 31T).
• Terminal Type: Screw Post – Terminal
• Hold-Down/Tray: Commercial trays vary—confirm the base/foot and clearance.

Reference Specs (Compare to Your Existing Battery)

• Interstate 31-MHD reference: Group 31T, 12V, 950 CCA
• 31HD reference listing: Group 31T, 12V, 950 CCA

Common Applications

• Commercial trucks and fleet vehicles
• Industrial / agricultural equipment
• Marine applications needing strong cranking + reserve
• Backup/utility systems requiring dependable 12V performance

Key Features

• Replacement class for Interstate 31-MHD (verify Group 31 variant)
• 12V heavy-duty/commercial flooded battery category
• Strong starting performance (CCA class comparable to 31-MHD)
• Good reserve capacity for moderate engine-off loads
• Common fit for fleet, industrial, marine, and equipment use
• Fitment-first: check terminals + tray hold-down before ordering

FAQ

Does 31HD replace Interstate 31-MHD?

Often yes if the battery is the same Group 31 variant and matches your terminal type and hold-down. Interstate 31-MHD is commonly listed as Group 31T Screw Post.

What’s the difference between 31, 31T, 31A, and 31P?

They are Group 31 variations that may differ in case/terminal/fit details. Always match the exact group marking on your old battery and confirm the terminals.

Will this work in an exit sign or emergency light fixture?

No. Exit signs/emergency lights typically use small rechargeable battery packs (Ni-Cd/NiMH/Li-ion) with connectors—not a large Group 31 battery.

Can I upgrade to AGM?

Sometimes, if size/terminals match and your charging system supports AGM charging. If you share your application and charger/alternator details, we can advise.

Models This Battery Replaces

• Interstate: 31-MHD (commonly Group 31T)
• Equivalent class: Group 31 heavy-duty/commercial 12V battery (match terminals/fitment)