Optima vs Interstate Battery: How They Compare (October 2026)
Choose by vehicle fit and terminal layout first: Optima offers RedTop starting batteries, while Interstate's Group 78 AGM has 740 CCA and 115 minutes of reserve capacity.
On this page (7 sections)
- Optima vs Interstate battery: which should you choose?
- How do the Optima and Interstate batteries compare?
- When does the Optima RedTop 34/78 make sense?
- When is Interstate AGM Group 78 a better match?
- Should you choose the Optima RedTop 78 instead?
- What should you check before buying?
- Optima vs Interstate battery: what's the verdict?
Choose by vehicle fit and terminal layout first: Optima offers RedTop starting batteries, while Interstate's Group 78 AGM has 740 CCA and 115 minutes of reserve capacity. In this Optima vs Interstate battery comparison, the right choice depends on your car's required group size, posts and electrical needs.
The Optima RedTop 34/78 has dual SAE and GM posts, while the Optima RedTop 78 uses GM-style side terminals. Interstate's Group 78 AGM also has side posts, so compare the exact tray dimensions and cable positions before deciding.
Optima vs Interstate battery: which should you choose?
Choose the battery that matches your vehicle's required size and terminal layout; then compare its CCA and reserve capacity. Brand preference comes after fit because a battery that doesn't connect or sit correctly isn't a suitable replacement.
The Optima RedTop 34/78 lists 800 CCA and 100 minutes of reserve capacity. It has both SAE and GM posts, which can help when your vehicle requires that combination.
The Interstate AGM Group 78 lists 740 CCA and 115 minutes of reserve capacity. Its side-post design and Group 78 size may suit vehicles that specify those details.
The Optima RedTop 78 also lists 800 CCA and 100 minutes of reserve capacity. It has GM-style side terminals, so compare its exact dimensions and terminal position with the battery already in your vehicle.
How do the Optima and Interstate batteries compare?
The two Optima RedTops here list 800 CCA, while Interstate lists 740 CCA and more reserve capacity. These figures describe different battery capabilities and don't make one model the right fit for every vehicle.
The RedTop 34/78 and RedTop 78 each list 100 minutes of reserve capacity. Interstate's Group 78 AGM lists 115 minutes, which may matter if reserve capacity is a priority and the battery fits your vehicle.
All 3 are 12-volt batteries. The Optima models use SpiralCell technology, which Optima describes as using 99.99% pure lead; Interstate identifies its MTX-78 as an absorbed glass mat battery.
Which battery has the right terminals?
The RedTop 34/78 has dual SAE and GM posts. That layout differs from the side-post terminals on the RedTop 78 and Interstate Group 78 AGM.
Don't choose by terminal style alone. Check the positive and negative cable positions, post orientation and clearance around the hold-down, then confirm that the replacement fits the vehicle's battery tray.
Which battery has more reserve capacity?
The Interstate Group 78 AGM lists 115 minutes of reserve capacity, compared with 100 minutes for each Optima RedTop here. A higher figure can be useful when comparing batteries that already meet the vehicle's required fit and specifications.
Reserve capacity isn't a substitute for CCA or the vehicle's stated requirements. Read what battery reserve capacity means before weighing this figure against other specifications.
When does the Optima RedTop 34/78 make sense?
Consider the RedTop 34/78 when your vehicle accepts its size and dual SAE and GM posts. Its 800 CCA and 100-minute reserve capacity give you specific figures to compare against your current battery.
Optima describes its RedTop as a starting battery for basic electrical demands. It also says the battery is maintenance free and designed for vibration resistance, but those features don't override vehicle compatibility.
The dimensions are about 10.06 x 6.94 x 7.88 inches. Measure the tray and check the cable reach before ordering, especially if you are replacing a battery with different terminals.
Our car battery replacement guide walks through the fit and specification checks to make before you buy. If you aren't sure which group size your car needs, use the battery size guide to identify the next check.
When is Interstate AGM Group 78 a better match?
Choose Interstate when your vehicle calls for a Group 78 AGM battery with side posts and its stated starting requirements are compatible. The MTX-78 lists 740 CCA and 115 minutes of reserve capacity.
Interstate describes the MTX series as suited to AGM-required applications. Its Group 78 battery also lists a 36-month warranty, but warranty coverage and conditions should be confirmed for your purchase.
The battery's listed dimensions are about 10.94 x 7.31 x 7.24 inches. Compare them with your tray, cable positions and hold-down space, since a shared group-size label doesn't guarantee identical measurements.
The Group 48 vs 94R guide explains why size labels and vehicle fit need careful checking. Those groups differ from Group 78, but the same rule applies: confirm the exact size listed for your vehicle.
Should you choose the Optima RedTop 78 instead?
The RedTop 78 is a fit-first option if your vehicle requires its Group 78 size and GM-style side terminals. It offers 800 CCA and 100 minutes of reserve capacity.
Its listed dimensions are about 10.06 x 7.31 x 7.25 inches. Compare those measurements with the Interstate Group 78 AGM, which is listed at about 10.94 x 7.31 x 7.24 inches.
The similar group-size label doesn't mean the batteries are interchangeable in every vehicle. Check your manual or the existing battery label, and verify terminal orientation and clearances before choosing either one.
What should you check before buying?
Confirm the required group size, terminal positions and minimum starting specification before choosing a brand. Use the owner's manual or a trusted vehicle fit guide, then compare the replacement battery's measurements with the space available.
Check whether the vehicle requires AGM. The AGM vs lead acid car battery guide explains the battery-type differences, while how many cold cranking amps you need can help you understand the CCA figure.
If you're replacing a weak battery, test the battery and charging system before assuming the battery alone is the problem. Our guide to signs of a bad car battery covers common clues and what to check next.
Optima vs Interstate battery: what's the verdict?
Pick Optima RedTop 34/78 if your vehicle needs its dual-post layout, Interstate Group 78 AGM if it calls for that AGM size, and RedTop 78 if its side-terminal configuration is the match. Fit and required specifications decide between these batteries more reliably than brand name alone.
Before you order, compare your owner's manual, battery label and tray measurements. For more brand context, see our car battery brands comparison.
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Frequently asked questions
Is Optima better than Interstate for a car battery?
Neither brand is automatically better for every car. Compare the exact battery size, terminal layout, CCA and reserve capacity your vehicle requires.
The Optima RedTops here offer 800 CCA, while the Interstate Group 78 AGM has 740 CCA and 115 minutes of reserve capacity.
Is the Optima RedTop 78 the same size as Interstate Group 78?
Both are identified as Group 78 batteries, but check dimensions and terminal placement before buying. The Optima RedTop 78 measures about 10.06 x 7.31 x 7.25 inches and has GM-style side terminals; Interstate lists a Group 78 size and side-post terminals.
Does the Optima RedTop 34/78 have side terminals?
The RedTop 34/78 has dual SAE and GM posts, giving it both terminal styles. Confirm the vehicle's cable reach, terminal orientation and tray space, since the dual-post layout does not guarantee fit in every car.
Which matters more, CCA or reserve capacity?
Use the vehicle maker's required battery specifications as your starting point. CCA measures starting output in cold conditions, while reserve capacity describes how long a fully charged battery can deliver a set current.
Compare both when the vehicle allows a choice.
Can I replace a flooded battery with AGM?
Often, but only if the vehicle supports the battery type and the replacement matches its size, terminals and electrical requirements. Check the owner's manual and charging system guidance before switching; this AGM vs lead acid battery guide covers the main differences.
