Foxwell BT705
A sturdy 12 V and 24 V tester with a cable long enough to run the starter test alone, and a longer warranty than most.
Amazon $106.99$106.99
The Foxwell BT705 and the Topdon BT100 are evenly matched, rated 3.6 and 3.6. The Foxwell BT705 leads on battery coverage and features or load. The Topdon BT100 wins on price and system tests. The Topdon BT100 costs $53 less ($53.99 vs $106.99).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Topdon BT100
A low-cost 12 V tester for a car owner who wants to check a battery, starter and alternator at home.
Amazon $53.99$53.99
Which should you buy?
- Choose the Foxwell BT705 for battery coverage (up to 2,000 CCA, 24 V systems vs up to 2,000 CCA) and features or load (cable of 5 ft or more vs none of the listed features).
- Choose the Topdon BT100 for price ($53.99 vs $106.99) and system tests (tests the starter, charging system, ripple or diode vs tests the starter, charging system).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every digital testers car battery tester; a clear win is highlighted. How we rank explains each one.
| Factor weight | Foxwell BT705 | Topdon BT100 |
|---|---|---|
| Overall rating | 3.6/5 | 3.6/5 |
| Price 25% | 67 $106.99 | 97 $53.99 |
| Battery coverage 25% | 80 up to 2,000 CCA, 24 V systems | 60 up to 2,000 CCA |
| System tests 20% | 80 tests the starter, charging system | 100 tests the starter, charging system, ripple or diode |
| Features or load 20% | 10 cable of 5 ft or more | 0 none of the listed features |
| Warranty 10% | 50 2-year warranty | 0 warranty not published, scored as none |
Specifications
| Foxwell BT705 | Topdon BT100 | |
|---|---|---|
| Testing | ||
| Type | Conductance (digital) | Conductance (digital) |
| Battery voltages | 12/24 V | 12 V |
| System voltages | 12/24 V | 12 V |
| Rating range | 100-2,000 CCA | 100-2,000 CCA |
| Battery types | Flooded, AGM, gel, EFB | Flooded, AGM flat plate, AGM spiral, EFB, gel |
| Lithium batteries | No | - |
| Starter test | Yes | Yes |
| Charging system test | Yes | Yes |
| Ripple or diode test | - | Yes |
| Features | ||
| Display | 2.8 in screen | - |
| Stores results | - | No |
| Cable length | 5.9 ft | - |
| Build | ||
| Warranty | 2 years | - |