The ASUS Zenfone MAX (ZC550KL) has only one purpose: to be the lowest price smartphone with longest-lasting battery.
The new Zenfone Max, like the recent Zenfone Zoom, is starting to deviate from the 2015 Zenfone 2 design DNA. Although the front face remains unchanged, gone are the volume buttons at the back of the phone and the power button at the top. These are now positioned where most other smartphones are found – at the right. Also gone is the metallic-finish plastic back cover, replaced by faux leather texture. In my review unit, the edges are painted in metal-like gold colour, giving the Zenfone Max a more premium look than the predecessors. It is really hard to tell that it can be bought at just S$249 in Singapore.
Long-Lasting Battery
The killer feature of the Zenfone Max is its battery capacity: 5000mAh. The smartphone can be put on standby (flight mode) for more than a month. For my review, I managed to keep it alive for more than 5 days, with mobile and Wi-Fi networks enabled and occasional use to check the status.

Started 100% from 20 Feb till 25 Feb, with 20% remaining and expected 1 day 4 hours left, that means the Zenfone Max can truly last one full week with mobile network and Wi-Fi enabled!
When I use it normally with all the usual interactions on my emails, social networking apps, and messaging apps, the phone actually lasts 2 full days. This is double the life of any smartphone I have used ever.
With the huge battery life, naturally it takes a longer time to fully charge the Zenfone Max. But based on my test, I am able to get from 9% to 90% in 4 hours. I would recommend not waiting for the battery to drop too low before doing a charge, since it will take a long time to top it up (does not support Boost Master or Qualcomm Quick Charge 2.0).
A Phone That Can Charge Other Devices
There are so much juice that ASUS even included an OTG cable to allow Zenfone Max to charge other devices. The charge current appears to be just 0.5A, which is rather disappointing considering the charging feature is highly publicised. I took the opportunity to test other smartphones and find that they too could perform OTG charging. But Zenfone Max has a feature to ensure the OTG charging current remains active even after the device is in sleep mode. In spite of this feature, the Zenfone Max does not behave exactly like a portable power bank as the smartphone needs to be powered on before external charging can take place. I would stick to carrying a separate portable power bank and save the smartphone battery for the smartphone itself.
Basic Specs
In order to keep prices below S$250, ASUS has stripped down the hardware to its bare essentials.
– Snapdragon 410 1.2GHz quad-core
– SIM1 LTE Cat 4 download data speed up to 150Mbps
– SIM2 only supports 2G and 3G, no LTE
– 2GB RAM, 16GB Internal Memory
– external microSD up to 64GB
– Wi-Fi support up to N-band, does not support AC-band
– 5.5-inch screen is 1280 x 720 pixels, although casually I can’t tell the difference
– AC charger is rated 5V/1A instead of the more powerful 2A
The Antutu benchmark reveals a humble overall score of 25300 with unimpressed graphics score (3D: 310). Serious gamers will not be pleased, resulting in lags that would be unacceptable. Still, there are other use cases for a large-battery smartphone. For instance, you need to keep the screen always on and apps running on background (which drains a lot of battery), or you have no access to power source (so a large battery will keep you going for days), or you use the phone as Wi-Fi Hotspot (another power drainer but will be immensely useful).
The 1280 x 720 display is also not the best compared to the other Zenfone models. When put side-by-side, the white tone appears to be warmer and a little greenish. The contrast level is stronger with less details in the dark regions. But really, the target segment of the Zenfone Max would probably not be that concerned.
After using the phone extensively for 3 weeks (I always load all my usual stuff on review units to simulate real life usage), the Zenfone Max feels adequate in meeting my productivity and social engagement needs. The ZenUI remains relatively smooth with occasional system pauses in between tasks. Obviously, smartphones with higher specs would do much better. Zenfone Max certainly does not like to be pushed around too much, so you should go easy on multi-tasking and not expecting it to be immediately responsive all the time. So far, no undesirable app crashes. I am just so glad that I no longer have to worry about background-running apps that could drain the smartphone battery life.
Verdict
While the external charging feature might be a gimmick, its 5000 mAh battery is real. The budget-spec Zenfone Max is not a blazing performer, but will satisfy consumers who use the device for long periods without worry of recharging.
Would I buy it? Yes I would! The Zenfone Max is a perfect smartphone – as main or as backup – for times when you needed a communication device without worry of battery issues. The cost of ownership is low, and the ZenUI has almost everything one needs without having to source for third party apps. Official retail price in Singapore is $249,
I highly recommend the Zenfone Max to anyone who values battery life more than performance. I would prefer a smartphone that lasts me through my heaviest days of online engagement, than one that is so powerful that it drains the battery in mere hours.





9 comments
It amazes me that less than six months after launching, they already have a new updated model with Snapdragon 615 processor which is nearly indistinguishable, and has same prices/etc… I stupidly bought the old one today (Jul 2016).
Coming to your review point though, are you sure the 2nd sim can only do 2G/3G and not LTE? This seems to contradict the brochure which says they both support 4G.
Hi Jeff, the Zenfone Max is a different variant from the other Zenfone series, as it has the largest battery capacity among the Zenfones. According to the official website, it does state the 2nd SIM slot can only support 2G and 3G. https://www.asus.com/sg/Phone/ZenFone-Max-ZC550KL/specifications/
Thanks for that. After using it more extensively I can confirm both Sim slots support 4G however only one can connect to 4G at a time (and the other will drop down to 2G). This isn’t too bad since most people will only need one sims data plan at any one time however there seems to be a bug in Asus’ 6.0.1 marshmallow update preventing the second Sim data plan being used for wifi hotspot tethering. That and the phone gets stuck in a boot loop when you try to enable encryption.
Thanks for sharing your user feedback, Jeff!
holy shit….i just buy the old one today(19july 206) with the price of sgd 210.