Test/review of Tomo Power bank M4

Thank you for this review. I have three of the original version of this charger. And love them. I’ve put one through the ringer. I take to work with me. Its taken a beaten of you saw it in a recycle bin you wouldn’t even take it. Been dropped, plastic has chemical burns on it industrial bug repellant leaked in my bag and ate away at the plastic. I have to charge the batteries seperarly but these are great if you have piles of laptop pulls or tons of cells. The other two work around the house. I’d like to see a 2 amp charge rate. Instead of one amp.

I did have one die on me after one week of use, but imrbatteries took care of me in no time on it. I recommend if you want a cheap power bank you can swap cells on the go with. I’m not sure about the this new version. But the old one can take protected pana b. Its a tight fit but they fit and work.

Thanks for the review mate!

We can now call you HKJ the power bank killer :stuck_out_tongue:

My score is 3 for this year, two that could not handle maximum current and one that died at very low current.

So, how does this compare to the TLIFE?
Is there a difference in build quality, components?

Thanks a lot for the review. Looks just as bad as I have experienced. I don’t like how low the output voltage drops under load.

Also, if you happen to use this heap of mediocrity, you should never load the power bank with only one 18650. It heats up very much when discharged. Even with four batteries the efficiency is quite bad, I got 31.8 Wh out of four 18650GAs, which is about 67 %.

Just get a good 10000 mAh power bank like a Xiaomi, which is not only smaller but better in every way.

The only saving grace of the Tomo is that it’s very cheap and there’s not many like it.

I have the Tomo version of this power bank, and as said in the comment above the efficiency seems quite low a lot of power wasted as heat and not much getting into your phone/tablet.

The Xiaomi 10.000mah seems to be sold out on a lot of sites, It must be popular, Though i prefer power banks i can change the battery`s once the die.

John.

Thanks for the review.

I am not that familiar with these power banks other than the fact that several[3] could not take your test! :wink:

I have had 2 battery charger`s go bang from new, and another just die while charging so it must be catching.

John.

I like my Tomo Original very.

I don’t mind the low efficiency because you can recharge the bank and have infinite energy supply this way

The Tomo may not be perfect, but it have some advantages:

  1. Display of current
  2. Easy replacement of batteries (This makes it easy to carry spare batteries).

I do not use it because I want auto coding and preferable Quick Charge and I do not want to carry spare 18650 cells (Except two for my lights). This is personal choices and other people may have other preferences.

So what’s the difference between Tomo M4 and TLife TC-01 ?

The charge circuit must be different, but the boost converter looks to be about the same.

Just returned from a 3 week trip during which, what could go wrong did.

Butt I must say that my TOMO M4 worked as expected on my MP3 player, LG smartphone, a couple flashlights (Nitecore TIP, Astrolux S42), and provided extra 18650 batteries (and/or charging) for my Nitecore MH20GT. A single channel charger (XTAR in my case) powered by the TOMO covers most all my battery needs.

AA/AAA is another animal. Wish they would evolve.

I have TOMO S4 i accidentally connected its output terminal to input, now its not charging.

Just wondering, which is better: Tomo M4, T4 or S4?

SHOP - TOMO or SHOP - TOMO

What's the runtime of the powerbank when i connect a consumer with 0.5A?

I've got an USB fan, and i am going to

Depends on the capacity of the cells you put into the TOMO M4.

4x 3000mAh for example give you 44Wh capacity. A 0.5A fan needs 2.5W.
With the conversion losses the fan would run around 13 hours.

thanks @angerdan !

it's this graph, right?


With 4 cell the runtime is more than 4 times longer, here at 0.5A load.
Note: Current measurement is only for one cell.

I've got some old 4xNCR18650B for the test. Before going to bed, i'll pause the test, remove the batteries. I've got an omnicharge 4x18650B too, so i should do a runtime test with it too. Sounds like fair game. We will expect that the omnicharge has a longer runtime.

The current/voltage/wattage displayed numbers of TOMO, of USB doctor, or omnicharge are not precise because the numbers fluctuate (nature of any fan, hello?). Current draw looks around ~0.5A, so wattage should be ~2.5W, but omnicharge displays 3.0W. So maybe a more relevant practical measure for comparison is device runtime!!

  • TOMO V8-4 w/ 4xNCR18650B (old cells with few cycles, charge-tested avg. 4x3160mAh totalling 49.312Wh): USB fan runtime is a whopping 16h31m30s, i stopped it to the second yay. The four cells recovered after 24h to 4x3.264V offline.
  • omnicharge 4xNCR18650B (old cells with few cycles, nominal 49.500Wh): USB fan runtime is only 15h31m57s, i stopped it to the second. It is unclear to which voltage level the four cells recover after the fan has turned off.

I like this simple clear result. The tomo has a longer runtime than omnicharge, at least for this low current application (0.5-0.6A current draw). I don't think that the tomo has a better energy conversion efficiency. I believe that in the omnicharge the cells don't get discharged as much/deep as in the tomo (did @HKJ measure how deep the cells get discharged in the tomo?); this alone could explain why the tomo runtime is that much longer.

Oh for watt do i need the portable USB fan? — I thought of building a diy mosquito trap hehe. But in the end i solved the mosquitoes-in-tiny-room problem with some spray and a handheld vacuum. Lol!