Battery Tender Power Tender 3 A
#8 in Up to 5 AFull review
A versatile maintainer for garages with a mix of 6 V classics, 12 V cars and lithium powersport batteries.
Amazon $69.95$69.95
The Battery Tender Power Tender 3 A is the better battery charger overall, rated 3.6 to 2.9. The Battery Tender Power Tender 3 A leads on warranty, value and features. The Optima Digital 400+ wins on charge current. The Battery Tender Power Tender 3 A costs $80.04 less ($69.95 vs $149.99).
Optima Digital 400+
#12 in Up to 5 AFull review
A maintainer for owners of OPTIMA AGM or lithium batteries who want matched charge settings and a clear display. Others can get more amps for the money.
Amazon $149.99$149.99
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Battery Tender Power Tender 3 A for warranty (5-year warranty vs 3-year warranty), value ($23.32 per amp ($69.95, 3 A) vs $37.50 per amp ($149.99, 4 A)) and features (lithium mode, temperature compensation vs lithium mode).
- Choose the Optima Digital 400+ for charge current (4 A vs 3 A).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every up to 5 A battery charger; a clear win is highlighted. How we rank explains each one.
| Factor weight | Battery Tender Power Tender 3 A | Optima Digital 400+ |
|---|---|---|
| Overall rating | 3.6/5 | 2.9/5 |
| Value 35% | 47 $23.32 per amp ($69.95, 3 A) | 23 $37.50 per amp ($149.99, 4 A) |
| Charge current 20% | 50 3 A | 75 4 A |
| Features 25% | 50 lithium mode, temperature compensation | 25 lithium mode |
| Warranty 20% | 100 5-year warranty | 50 3-year warranty |
Specifications
| Battery Tender Power Tender 3 A | Optima Digital 400+ | |
|---|---|---|
| Charging | ||
| Charge current | 3 A | 4 A |
| Voltage | 6/12 V | 12 V |
| Largest battery | 100 Ah | - |
| Lithium mode | Yes | Yes |
| AGM mode | No | Yes |
| Temperature compensation | Yes | No |
| Repair mode | No | No |
| Power supply mode | No | No |
| Build | ||
| Ingress rating | IP65 | - |
| Weight | 1.4 lb | 3 lb |
| Warranty | 5 years | 3 years |
| Released | 2015-10-17 | 2024-04 |