Review: Seidio 3500mAh Battery for Palm Treo Pro


The Seidio 3500mah battery for the Palm Treo Pro ($69.95) is hands down the mother of all batteries. More than doubling the stock 1500mAh version, it offers unparalleled power and performance for those with an insatiable thirst for WM usage.

Of course the big question on everyone’s mind besides battery longevity is size. Surprisingly it is quite modest in girth and in a lot of ways, makes the Treo Pro, dare I say, feel better?

Curious about how long a monster 3500mah battery will get you at 528MHz? Wondering how it compares in size to the 800w, Moto Q9c and others? Read on for my take.

Lets cut to the chase: 3500mAh is a lot of juice for a battery. The Treo Pro already gets a rated 5hr talk time for CDMA, which itself is on the top end of performance for a stock device. Doubling that and tossing in another 500mah is borderline ludicrous, yet because the Treo Pro is already so thin, it actually works here.

For $69.95 you get the battery and the replacement cover. The latter is made with Seidio’s “soft touch” paint, which gives the Treo Pro a two-toned look and feel. The matte black does contrast a bit with the glossy front, but I think it works better for function as the soft touch paint feels like a combo of silk and felt in texture. Seidio did a great job with the back cover as there is zero wasted space — it forms perfectly to the extended battery and not a bit more, thereby minimizing any increase in size. At first touch, the cover feels awfully thin but so far in 3 weeks of use, not a single problem. 


The cover leaves room for the camera and speaker, though it looks odd because the camera is recessed so far into the body. Yet this recessed camera port is now a perfect grip for your index finger when on phone calls — no joke! 


Size Comparison

So how much bigger is the Treo Pro with this battery? In terms of thickness, at the greatest point (the center) it is as thick as an 800w or Mogul. But unlike those devices, the Treo Pro with this battery quickly slopes off all around the edges, giving it a more rounded and smaller profile. In other words, if you used an 800w (with the 1150mAh battery!), a Treo Pro with a 3500mAh is still smaller overall. This applies to the Mogul too.

A Moto Q9c is still much wider than a Treo Pro and in terms of thickness is still thinner even with its 1800mah battery. Having said that I think the Treo Pro still feels better in the hand.

My conclusion on size is this: I actually prefer the 3500mAh battery and cover to the stock Treo Pro. That’s right. For one, I don’t like the glossy stock cover: too slippery and too many fingerprints. Both issues are eliminated with Seidio’s cover, which just feels so nice to the touch. Second, the added thickness makes the Treo Pro feel sturdier when typing and just gripping it. Perhaps I’m just a freak, but after 3 weeks that is my conclusion.

In fact, size is not as noticeable as compared to say weight. No argument this 3500mah battery adds a few ounces and if you insist on carrying your phone in your pocket, will certainly notice the change. Holster users won’t. 


The real reason you bought the darn thing, right? Well here are some real-world examples. At my job, I have a fringe CDMA signal and after 14 hours of Exchange push, 10 hours of IM+, a few phone calls and about 2 hours of Internet and PDA functions, I was left with 48 percent battery. Or the other night I streamed 3½ hours of Kinoma Play podcasts, IM+ on for 7 hours, bunch of e-mails and 1 hour of Internet surfing and still had 52 percent battery left.

In other words, getting around 12 hours of talk time or 8-9 hours of constant 3G use seems quite realistic. From my experience, this battery is very tough to kill in a single day — you really have to go out of your way to do so. And it is quite easy to go two full days with realistic, regular WM usage and not even bat an eye at your remaining battery.



In short, I really like this battery!

For the first time with a WM Pro device, I feel like I can unleash everything: WiFi, BT, 3G, GPS and run any app such as a constant-connect IM app, push email, phone calls etc. and not even have to think about power consumption. It’s odd to see after about 5 hours of a moderate usage to still have 91 percent battery left. Throw in the fact that I actually like the size and feel over the stock and this battery is a winner. I keep it on no matter if it is a light day or a heavy one.

Now, let me put that into context: If you put the Treo Pro in your pocket then you probably won’t care for the size and weight increase. Just imagine an 800w or Mogul for a rough idea if you are unsure — if those worked for you, then this will, too. If you are a holster/side case user, then don’t even worry. It works great with Seidio’s Spring-clip holster (review next week) and their Inno Dock Jr.

Does everyone need this? Probably not. But if you are a “power user,” like to stream a lot (Sling Player, Kinoma, etc.), use Wifi often (or wished you could!) then you might want to give this a shot. I promise, it’s not that big. The price of $69.95 seems on the high end till you compare it to regular replacement batteries—we’re talking $20 more for much more juice and I certainly feel it is worth the cost.

One other "cool" feature is your Treo Pro seems less hot with this battery after prolonged use, no doubt attributed to having more mass to absorb/displace the heat.  Something to think about.

This is a killer accessory for the Treo Pro and will allow you to unleash all that 3g goodness and alleviating any fears of remaining battery.


  • Largest battery available
  • Great cover, very comfortable to use
  • Delivers on power


  • Little bit pricey (but not when comparing)
  • Treo Pro is not as thin as she used to be!
  • Probably too large for pocket users

Overall:  Highly recommoneded and well worth the money if needed

George Ponder

George is the Reviews Editor at Windows Central, concentrating on Windows 10 PC and Mobile apps. He's been a supporter of the platform since the days of Windows CE and uses his current Windows 10 Mobile phone daily to keep up with life and enjoy a game during down time.