UDPower Our score 6.8/10 #1 of 4 small for real capacity
UDPower C400
Updated
A 6.3 lb, 256 Wh station with a built-in car jump starter, aimed at drivers and campers who want one box for both jobs.
Independent tests put this portable power station's usable capacity at 221 Wh, 86% of the rated 256 Wh (one test so far).
Real capacity
221of 256 Wh
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CNET
86%
AC output
400 W
More than 1 of the 3 other small models we review. 800 W surge.
Cost per usable Wh
$0.77
#26 of 33 models we've priced.
PriceyWeight
6.3 lb
35 usable Wh per lb
Battery
LiFePO4
Long-life chemistry
Warranty
5 years
Wall charge
–
To full, maker’s figure
How much of the 256 Wh do you get?
Each bar is the full rated capacity. Blue is what the tester measured coming out of the AC outlets; the striped end is what was lost.
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CNET 221 Wh · 86%
How long will it run your devices?
Add what you want to power and see how long the UDPower C400 lasts on its tested 221 Wh, counting the power it uses on itself and any solar panels you add.
Our score: 6.8 out of 10
Worked out from the tested capacity and the specs on this page, compared with the other models we track. Capacity, power and charging are compared with the 4 small models; battery, build and features with all 37. Price isn't part of it. How we score.
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Capacity and power 35% of the score 7.0
What goes into capacity and power Measure This model Score Tested usable capacity 60% 221 Wh 6.9 Continuous AC output 25% 400 W 6.9 AC surge 15% 800 W 7.5 Compared with the 4 small models we track. Scores run from 5 to 10; 7.5 is the middle of the group.
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Charging 25% of the score 6.1
What goes into charging Measure This model Score Wall charge to full 40% Not known Left out Max solar input 35% 150 W 6.9 UPS switchover 25% No UPS mode 5.0 Compared with the 4 small models we track. Scores run from 5 to 10; 7.5 is the middle of the group. Measures we have no figure for are left out.
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Battery and build 25% of the score 8.2
What goes into battery and build Measure This model Score Battery type 30% LiFePO4 10.0 Cycle life to 80% 25% 3,000 cycles 5.7 Warranty 25% 5 years 8.5 Usable Wh per lb 20% 35 Wh/lb 8.0 Compared with all 37 models we track. Scores run from 5 to 10; 7.5 is the middle of the group.
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Features 15% of the score 5.1
What goes into features Measure This model Score Expandable battery 25% No 5.0 AC + USB-C outlets 20% 4 5.6 USB-C max output 15% 65 W 5.2 240 V output 15% No 5.0 App control 15% No 5.0 Wheels 10% No 5.0 Compared with all 37 models we track. Scores run from 5 to 10; 7.5 is the middle of the group.
Pros and cons
Pros
- Delivered 86% of rated capacity in CNET's test, right on the median.
- Built-in 12 V jump starter port.
- Very light at 6.3 lb.
- Its manual lists UL 2743, the safety standard for portable power packs.
Cons
- Only 400 W of AC output.
- No battery backup (UPS) mode and no app.
- Slow to charge: CNET measured 3 hours 5 minutes.
- Only one test so far, and we haven't found it on UDPower's own US store.
Who it's for
Drivers, campers and tailgaters who want a small power bank that can also jump-start a car.
Who should skip it
Skip it if you need battery backup for a computer or router, or anything over 400 W.
Features
- Battery backup (UPS) mode : no
- Takes extra batteries : no
- LiFePO4 battery : yes
- Solar input, 150 W : yes
- Car charging : yes
- 240 V output : no
- RV outlet (TT-30) : no
- App control : no
- Wheels : no
How it compares with other small models
| Model | Usable | Delivered | Price | Value |
|---|---|---|---|---|
| UDPower C400 256 Wh rated | 221 Wh | 86% | $169.99 | Pricey |
| EcoFlow RIVER 3 Plus 286 Wh rated | 218 Wh | 76% | $299 | Pricey |
| Anker SOLIX C300 288 Wh rated | 234 Wh | 81% | – | No price checked yet |
| BLUETTI Elite 30 V2 288 Wh rated | 232 Wh | 80% | $289.99 | Pricey |
Questions
How much usable power does the UDPower C400 have?
CNET measured 221 Wh at its standard 480 W load, against a rated 256 Wh.
Can the UDPower C400 jump-start a car?
It has a built-in 12 V jump starter port, according to UDPower. We haven't seen an independent test of the jump starter.
Full specs
From the maker's US manual or product page unless noted. Each value links to where we found it.
Capacity and battery
- Maximum with extra batteries
- Not expandable
- cdn.shopify.com (source for Maximum with extra batteries)
Output and ports
- AC surge
- 800 W UDPower's page calls this the peak in its UD-TURBO mode.
- cdn.shopify.com (source for AC surge)
Charging
- Wall charge to full
- Not published
- UPS switchover time
- Not published
Size and build
- Weight
- 6.3 lb From the manual. UDPower's product page says 6.88 lb.
- cdn.shopify.com (source for Weight)
Warranty and certification
- Released
- Not published
Where this data comes from
Capacity figures come from the independent testers linked above. We record their numbers, the date and the load, and link to their reports; the testing is theirs. Specs come from UDPower's own US documents, and we note where they disagree with each other or with test results. Prices are checked by hand on the brand's US store.