Ohmmu H7 MAX 120Ah Lithium 12V Battery Review — Is It Worth It? [2026]

In-Depth Review · 2026

Ohmmu H7 MAX 120Ah Lithium 12V Battery

An H7-size lithium 12V battery built to replace the OEM lead-acid unit in EVs like the Silverado EV and Hummer EV.

$679.00

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120Ah

Capacity

260

Reserve Capacity

26 lb

Weight

4 yr

Warranty

Quick Verdict

Is the H7 MAX worth buying?

For owners of EVs that use an H7 12V battery, it is a sensible upgrade if you are tired of replacing the lead-acid original. Ohmmu pitches higher usable capacity, better voltage stability and a much longer service life. The smart Bluetooth BMS and self-heating are the standout features. It is also the priciest battery in this roundup at $679, so it is only worth it if you keep your vehicle a while.

Great forOwners of Chevrolet Silverado EV, GMC Hummer EV and Sierra Denali EV and other H7 vehicles.

Reconsider ifYour vehicle uses a different battery size, or you want the cheapest possible replacement.

Overview

A smarter 12V battery for modern EVs

EVs still use a small 12V battery for accessories, locks and electronics. The H7 MAX is an Electrified Series drop-in with a Bluetooth BMS, self-heating cells and 120Ah of dual-purpose capacity. Outside the USA you may need SAE to JIS adapters.

Key Features

What the H7 MAX offers

01 · Capacity

120Ah dual purpose

120Ah and 260 minutes of reserve capacity give accessory power more headroom than a typical sealed lead-acid unit.

02 · BMS

Bluetooth BMS

The BMS balances cells and protects against over/undervoltage, overcharge, temperature extremes and short circuits, and the app tracks state of charge and lifecycle data.

03 · Winter

Self-heating

Heating elements warm the cells during charging in extreme cold so the car starts reliably in a harsh winter.

04 · Voltage

Cleaner power

A higher nominal voltage means brighter LEDs and better audio performance without voltage sag, per Ohmmu.

Specifications

Full spec sheet

Ohmmu Electrified Series H7 MAX — 120Ah Lithium 12V
Amp hours	120Ah
Reserve capacity	260
Dimensions	314 x 175 x 190 mm (12.4 x 6.9 x 7.5 in)
Weight	26 lb
Terminals	SAE, positive top back left
Fits	Vehicles using an H7 12V battery
Examples	Silverado EV, Hummer EV, Sierra Denali EV
Warranty	4 years, 100% replacement on performance failure
Spec sheet	Available for download

The Balance

Pros & Cons

Pros

Drop-in for H7 vehicles.
Self-heating plus Bluetooth BMS.
4-year full replacement warranty.
Much lighter than lead-acid.
Downloadable spec sheet.

Cons

The most expensive battery in this lineup at $679.
Warranty claims require inspection decided by Ohmmu.
JIS-terminal vehicles outside the US need adapters.
Only helpful if your vehicle really uses an H7.

FAQ

Answers before you buy

Which vehicles does it fit?

Any vehicle that uses an H7 12V battery, including the Chevrolet Silverado EV, GMC Hummer EV and GMC Sierra Denali EV.

Does it have a smart BMS?

Yes, Bluetooth-enabled with an app for state of charge and diagnostics.

How cold can it go?

It self-heats during charging in extreme cold. No specific temperature rating is listed on the page.

What warranty comes with it?

4 years, with full replacement coverage on performance failure.

Can I use it outside the US?

Possibly, but you may need SAE to JIS adapters.

4.3/5

Overall Score

Worth it for H7 EV owners

A well-featured upgrade that will cost more up front but should last. Editorial score only.

Get the H7 MAX · $679.00 →

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Last updated: October 5, 2026 · Reviewed by the Teelacodes Editorial Team.