Slickdeals is community-supported.  We may get paid by brands for deals, including promoted items.
Heads up, this deal has expired. Want to create a deal alert for this item?
expired Posted by Bruinnn | Staff • Feb 10, 2024
expired Posted by Bruinnn | Staff • Feb 10, 2024

Romoss 30000mAh 30W Fast Charging Portable Power Bank

+ Free Shipping

$26

$46

43% off
Amazon
69 Comments 51,235 Views
Visit Amazon
Good Deal
Save
Share
Deal Details
ROMOSS Direct via Amazon has Romoss 30000mAh 30W Fast Charging Portable Power Bank for $25.99 after clipping the $20 coupon on the product page. Shipping is free.

Note: Must be logged in to clip coupons; coupons are typically one-time use.

Thanks to Staff Member Bruinnn for posting this deal.

Features:
  • QC30W & PD27W Rapid Charging
  • 30000mAh High Capacity
  • 3 Output Ports: 1xUSB-C Port and 2x USB-A ports
  • 3 Input Ports: Micro USB, Lightning, Type-C ports
  • Smart LED Indicator: Help you easy to track the battery power, current, and voltage.
  • Fully recharge in less than 8 hours with an 18W wall charger(Not Included)
  • What's included: 3000mAh Power Bank x 1, USB cable x 1. User manual x 1 & Free 12-month warranty.

Editor's Notes

Written by powerfuldoppler | Staff
  • About this product:
    • Rating of 4.7 from over 3,600 Amazon customer reviews.
  • About this store:
  • Additional note:
    • Please see original post for additional details & give the WIKI and additional forum comments a read for helpful discussion. 

Original Post

Written by Bruinnn | Staff
Community Notes
About the Poster
Deal Details
Community Notes
About the Poster
ROMOSS Direct via Amazon has Romoss 30000mAh 30W Fast Charging Portable Power Bank for $25.99 after clipping the $20 coupon on the product page. Shipping is free.

Note: Must be logged in to clip coupons; coupons are typically one-time use.

Thanks to Staff Member Bruinnn for posting this deal.

Features:
  • QC30W & PD27W Rapid Charging
  • 30000mAh High Capacity
  • 3 Output Ports: 1xUSB-C Port and 2x USB-A ports
  • 3 Input Ports: Micro USB, Lightning, Type-C ports
  • Smart LED Indicator: Help you easy to track the battery power, current, and voltage.
  • Fully recharge in less than 8 hours with an 18W wall charger(Not Included)
  • What's included: 3000mAh Power Bank x 1, USB cable x 1. User manual x 1 & Free 12-month warranty.

Editor's Notes

Written by powerfuldoppler | Staff
  • About this product:
    • Rating of 4.7 from over 3,600 Amazon customer reviews.
  • About this store:
  • Additional note:
    • Please see original post for additional details & give the WIKI and additional forum comments a read for helpful discussion. 

Original Post

Written by Bruinnn | Staff

Community Voting

Deal Score
+54
Good Deal
Visit Amazon
Leave a Comment
To participate in the comments, please log in.

Top Comments

The one in OP delivers 30W of power, the one you linked is rated at 18W. So slightly faster charging. Both are rated as the same 30,000mah, which will prevent you from taking on an airplane. Airlines only allow 27,000 mAh / 100Wh max.
Sure, a naive approach would be to multiply out the percentages to get an approximate capacity of 19,166 mah. That fails to take into account a couple fairly significant factors, charging losses and power consumption of the phone itself.


Ever notice how when charging both the phone and the battery pack gets warm? That's because the battery pack has to boost the internal voltage to 5v (often upwards of 90% efficient, but never 100%) and your phone has to take that 5v and step it back down to the phone's internal battery voltage, with similar losses. If your phone was quick charging, the efficiency drops even more, but it's hard to quantify since there's a lot of variance.


And then there's the power your phone uses that's never delivered to the internal battery. Your phone was still on when it was charging yeah? Well that power came from the battery pack, and when phones are plugged in they turn off most power saving measures. How much power does that take? Well who knows, you have no way of directly measuring it by just glancing at (wildly inaccurate) capacity gauges.


If you want to accurately measure how much power a power bank delivers without just wholly making shit up, you have to get something that actually measures how much power was delivered [amazon.com]. That doesn't account for the internal losses in the battery pack circuitry, but it'll get you in the ballpark. Ideally you'd charge the pack from empty through that, save the result, then charge a load from the battery until the battery is flat, and the battery capacity will be roughly halfway between the two results. It's more work than just plugging in your phone, but just plugging in your phone is only slightly better than just taking a wild ass guess.
Formula to convert mah to Wh is (mAh)*(V)/1000 = (Wh). This battery pack claims to be 30,000mAh, So 30,000 x 3.7V/1000 = 111Wh. This would be over this limit. But the regulation says you can carry-on batteries as large as 160Wh with airline approval. I've never attempted to travel with anything larger then 20,000mah/74Wh.

69 Comments

Sign up for a Slickdeals account to remove this ad.

Feb 10, 2024
36 Posts
Joined Feb 2024
Feb 10, 2024
BlueActivity1265
Feb 10, 2024
36 Posts
How does the one the OP linked differ from this: https://www.amazon.com/dp/B07R8YP...ct_details

I recently received the one I linked and will be sending it back as it drained too quickly recharging.
1
Feb 10, 2024
221 Posts
Joined Jan 2009
Feb 10, 2024
Carljammers
Feb 10, 2024
221 Posts

Our community has rated this post as helpful. If you agree, why not thank Carljammers

Quote from BlueActivity1265 :
How does the one the OP linked differ from this: https://www.amazon.com/dp/B07R8YP...ct_details

I recently received the one I linked and will be sending it back as it drained too quickly recharging.
The one in OP delivers 30W of power, the one you linked is rated at 18W. So slightly faster charging. Both are rated as the same 30,000mah, which will prevent you from taking on an airplane. Airlines only allow 27,000 mAh / 100Wh max.
7
3
Pro
Feb 10, 2024
3,203 Posts
Joined Jul 2003
Feb 10, 2024
edrock200
Pro
Feb 10, 2024
3,203 Posts
Quote from Carljammers :
The one in OP delivers 30W of power, the one you linked is rated at 18W. So slightly faster charging. Both are rated as the same 30,000mah, which will prevent you from taking on an airplane. Airlines only allow 27,000 mAh / 100Wh max.
Where do you see the 27k mah limit? I've only seen the 100Wh limit https://www.tsa.gov/travel/securi...%20battery.
3
Feb 10, 2024
13,238 Posts
Joined Dec 2011
Feb 10, 2024
Peerless_Warrior
Feb 10, 2024
13,238 Posts

Our community has rated this post as helpful. If you agree, why not thank Peerless_Warrior

Quote from edrock200 :
Where do you see the 27k mah limit? I've only seen the 100Wh limit https://www.tsa.gov/travel/securi...%20battery.
This is 111Wh.
2
2
Feb 11, 2024
221 Posts
Joined Jan 2009
Feb 11, 2024
Carljammers
Feb 11, 2024
221 Posts

Our community has rated this post as helpful. If you agree, why not thank Carljammers

Quote from edrock200 :
Where do you see the 27k mah limit? I've only seen the 100Wh limit https://www.tsa.gov/travel/securi...%20battery.
Formula to convert mah to Wh is (mAh)*(V)/1000 = (Wh). This battery pack claims to be 30,000mAh, So 30,000 x 3.7V/1000 = 111Wh. This would be over this limit. But the regulation says you can carry-on batteries as large as 160Wh with airline approval. I've never attempted to travel with anything larger then 20,000mah/74Wh.
3
Feb 11, 2024
3,178 Posts
Joined Nov 2012

This comment has been rated as unhelpful by Slickdeals users.

Feb 13, 2024
1,688 Posts
Joined Aug 2011
Feb 13, 2024
NateRules
Feb 13, 2024
1,688 Posts
If I am buying a generic battery, might as well grab this one for 15 bucks. It's claimed to be bigger. https://www.amazon.com/Portable-C...23BW9&th=1

Sign up for a Slickdeals account to remove this ad.

Feb 13, 2024
2,952 Posts
Joined Aug 2013
Feb 13, 2024
ChillO8033
Feb 13, 2024
2,952 Posts
Quote from ablang :
How many times can this charge my iPhone X 256GB phone?
eleven
4
Feb 13, 2024
3,180 Posts
Joined Jan 2019
Feb 13, 2024
GeoffreyK24
Feb 13, 2024
3,180 Posts

Our community has rated this post as helpful. If you agree, why not thank GeoffreyK24

Quote from NateRules :
If I am buying a generic battery, might as well grab this one for 15 bucks. It's claimed to be bigger. https://www.amazon.com/Portable-C...23BW9&th=1
Be aware, the one you linked seems like a no brainer if you take their claims as gospel but 7% of reviews are 1-Star and pretty much all of them claim significantly less capacity (as little as 1/4 advertised capacity) compared to the listing claims. When I saw that link, I almost pulled the trigger too so if you ordered it, I would be very interested to know how it works out for you.

Thanks!
2
1
Feb 13, 2024
369 Posts
Joined Dec 2003
Feb 13, 2024
rooster
Feb 13, 2024
369 Posts
Quote from ablang :
How many times can this charge my iPhone X 256GB phone?
Theoretically 11...but realistically 5 or 6 times due to inefficiency losses and the way that they rate these battery packs
1
Feb 13, 2024
3 Posts
Joined Feb 2024
Feb 13, 2024
StrongRaccoon3612
Feb 13, 2024
3 Posts

Our community has rated this post as helpful. If you agree, why not thank StrongRaccoon3612

Just to be clear, I've traveled Europe, North America, South America with this exact powerbank and I have never been stopped with this in my carry on.

I would also say this is one of the single best pieces of tech I have ever owned. The first one lasted from 2020 - 2024 before it started ballooning. The second one I just got. The first I absolutely abused. We are talking tossed in a bag, camping music festivals, Burning Man with the Alkaline dust, snowstorms, you name it.

I charge this in roughly 2 hours from 0 with a macbook pro charger, but you can charge with USBC, MicroUSB, and Lightning. It also works, unlike most batteries as pass through. So when I go away I often do not even bring a block, Just plug this into the wall, and plug the usb device in and press the button. This also means if you have more than one of these you can daisy chain them to charge all of them overnight.

This gets roughly 8 iphone X charges, 5 full Fold5 charges, 2 Ipad pro, and can even slowly trickle charge a macbook pro.

This is a no brainer, even for emergency power. Lowest i've ever bought it is $21 from Amazon. Worth every penny.

Finally, these go on sale all the time, but pair it with a pack of these

https://www.amazon.com/Basesailor...107&sr=1-3

And you will never be without the correct charging port.

If you have not clicked checkout now you are doing a disservice to yourself.
1
9
Feb 13, 2024
3 Posts
Joined Feb 2024

This comment has been rated as unhelpful by Slickdeals users.

Feb 13, 2024
3 Posts
Joined Feb 2024
Feb 13, 2024
StrongRaccoon3612
Feb 13, 2024
3 Posts
Quote from ablang :
How many times can this charge my iPhone X 256GB phone?
I get around 8-9 when the battery is new.

Still after 4 years around 3
4
Feb 13, 2024
5,404 Posts
Joined Sep 2012
Feb 13, 2024
NEW0
Feb 13, 2024
5,404 Posts
I guess I'm not as well traveled as some of you, but it may be worth sharing that in my own experience, the only place I ever had an airport actually read the power bank numbers and scrutinize it was in Japan. Ymmv of course.

I don't think I have this exact model, but I think I have a much bigger capacity one and it has been fine so far. I don't use it heavily but it has survived not being used for a while and as far as I can tell, hasn't suffered greatly capacity-wise from not being used
1
1

Sign up for a Slickdeals account to remove this ad.

Feb 13, 2024
244 Posts
Joined Nov 2015
Feb 13, 2024
yokitty
Feb 13, 2024
244 Posts
I have the 20000 mAh version, and it's heavy enough to kill a small elephant if thrown correctly. I like it, but sheesh.

What the hey, in for one. Never know when I might need to kill a slightly larger elephant.
6

Popular Deals

View All

Trending Deals

View All