# Battery Tender Plus (021-0128) vs Digital 1200: specs and price compared

A sourced, side-by-side comparison of the Battery Tender Plus (021-0128) (Battery Tender) and Digital 1200 (OPTIMA) among car battery chargers.

## Side by side

| Spec | Battery Tender Plus (021-0128) | Digital 1200 |
| --- | --- | --- |
| US price | not published | not published |
| Brand | Battery Tender | OPTIMA |
| Max charge amps | 1.25 | 12 |
| Voltage support (V) | 12 | 12 |
| Battery chemistry | Flooded, Sealed/GRT (Gas Recombinant Technology), and AGM 12V lead-acid batteries | AGM and Flooded 12V lead-acid batteries, including OPTIMA RedTop/BlueTop/YellowTop and standard automotive/marine/motorcycle batteries |
| Modes | Fully automatic 4-step charging: bulk charge, absorption, and adaptive float/maintenance (ISM) | 6-stage fully automatic charging; Charging Quick-Set Selector (Engine Start/Aging, 12V High-Performance AGM, 12V Standard Flooded & AGM, Motorcycle/Auto/Marine) plus a separate Maintainer Quick-Set Selector (Battery Maintainer, Aux Maintainer up to 4A) |
| Waterproof rating | — | — |
| Reverse polarity protection | — | Yes |
| Display | 3-LED indicator (red = bulk charging, flashing green = absorption, solid green = float/complete) | Circular backlit LCD gauge (Volts DC, Amps DC, charge-stage text) with an LCD-backlight toggle |
| Temperature compensation | — | Yes |

## Key differences

- Max charge amps: Battery Tender Plus (021-0128) 1.25 vs Digital 1200 12
- Battery chemistry: Battery Tender Plus (021-0128) Flooded, Sealed/GRT (Gas Recombinant Technology), and AGM 12V lead-acid batteries vs Digital 1200 AGM and Flooded 12V lead-acid batteries, including OPTIMA RedTop/BlueTop/YellowTop and standard automotive/marine/motorcycle batteries
- Modes: Battery Tender Plus (021-0128) Fully automatic 4-step charging: bulk charge, absorption, and adaptive float/maintenance (ISM) vs Digital 1200 6-stage fully automatic charging; Charging Quick-Set Selector (Engine Start/Aging, 12V High-Performance AGM, 12V Standard Flooded & AGM, Motorcycle/Auto/Marine) plus a separate Maintainer Quick-Set Selector (Battery Maintainer, Aux Maintainer up to 4A)
- Display: Battery Tender Plus (021-0128) 3-LED indicator (red = bulk charging, flashing green = absorption, solid green = float/complete) vs Digital 1200 Circular backlit LCD gauge (Volts DC, Amps DC, charge-stage text) with an LCD-backlight toggle

## Sources

- Battery Tender Plus (021-0128): https://www.manualslib.com/manual/1661410/Battery-Tender-Plus-12v1-25a.html (manualslib.com, verified 2026-08-01)
- Digital 1200: https://www.manualslib.com/manual/1007194/Optima-Digital-1200.html (manualslib.com, verified 2026-08-01)

Canonical: https://frontdeskreview.com/gear/car-battery-chargers/battery-tender-plus-021-0128-vs-optima-digital-1200/
Cite: Per The Front Desk Review, Battery Tender Plus (021-0128) (not published) vs Digital 1200 (not published) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/car-battery-chargers/battery-tender-plus-021-0128-vs-optima-digital-1200/
License: CC BY 4.0.