What to know about Battery Tender 021-0128
Why it stands out
Why we like it
It is ETL/cETL listed and CEC/DOE compliant, and its 10-year limited warranty is the longest here. Battery Tender says initialization recovers batteries from 2V to 11.9V, though Reviewed and The Drive testers report it needs about 3V to start.
What to know
Score breakdown
How safely and reliably it holds a battery at full charge for months: automatic float/pulse maintenance, overcharge protection, temperature compensation, behavior after power loss, ability to restart on low batteries.
Supported voltages (6V/12V), chemistries (flooded, AGM, gel, LiFePO4), and rated battery capacity relative to the vehicles people store (motorcycles to trucks/RVs).
Set-and-forget operation, clarity of status LEDs/display, lead length, ring-terminal/quick-disconnect harness, mounting.
Build quality, IP rating, rated low operating temperature for unheated garages, warranty length and reported failure rates.
Third-party electrical safety marks (UL/ETL), spark-proof and reverse-polarity protection, CEC/DOE efficiency compliance (maintenance-mode draw), recall history.
Price relative to capability, warranty and the battery sizes it can serve.
Battery Tender 021-0128 specs
Charging
- Max charge current
- 1.25 A
- Charging banks
- 1 banks
- Charges deeply discharged (<1V) batteries
- Yes
Compatibility
- Battery voltages
- 12V
- Battery chemistries
- Flooded, AGM, gel, sealed maintenance-free lead-acid
- Lithium (LiFePO4) mode
- No
- Max rated battery capacity
- 80 Ah
Build
- Warranty
- 10 years
- Power source
- AC wall outlet
Safety
- Safety / efficiency certifications
- ETL & cETL; FCC, ICES, CEC, DOE
Compare prices
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Prices and availability may change. The retailer's price and availability at checkout govern the transaction.
| Retailer | Price | Availability | |
|---|---|---|---|
| AmazonLowest | $58.95 | In Stock | View deal |
| Walmart | Check price at retailer | Check at retailer | Check at retailer |
Based on 2 retailer price observations captured during the last 90 days.