iRobot Roomba 870 Review by Janyce Raynolds
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It’s a little mysterious why iRobot chose to produce the Roomba 870 vacuum cleaner at all. It’s so similar to other recent models you have to wonder where they thought the market niche might lie. Still, if you look at the details, the answer becomes – if not plain, at least plausible.
Basic Design & Specs
Like virtually every other iRobot vacuum cleaner, the Roomba 870 sports a low-slung disc-shaped body. It measures 13.9 inches in diameter and stands a mere 3.6 inches high.
The weight is similar to others as well: 8.4 lbs. Even the coloring is quite familiar – black with gray highlights.
That said, while there appear to be few major changes from previous models – especially those on the high end of the line – the evolutionary ones make this robot worth investigating.
Battery & Lifetime
The first of those improvements is one that isn’t obvious until you actually use the 870 a few times. Here I’m not talking about the suction power, but the battery.
Open up the case and you’ll find a brick that looks very much like previous power plants, except for its blue color. Indeed, like past models, the battery contains 12 sub-c NiMH cells with a total of 3000 mAH capacity. Yet, for all that similarity, this latest Roomba really does deliver more vacuuming life per battery.
That comes not in the form of longer floor-cleaning times. It still runs for about an hour between charges. Fortunately, longer session times aren’t really needed, except perhaps in homes so large the owner could hire a maid.
But the total recharge cycles, it seems, has been considerably enhanced. It’s too early to have tested the claim fully, but iRobot heralds “twice as many as on past models”. Based on firmware changes and battery improvements on other products (like the last MacBook Air, for example), it’s plausible. It’s possible – and has been done elsewhere – to get double the lifetime out of a battery by more intelligent usage.
Since battery replacement on any robot device is typically 7% or more of the total original price, stretching it out can radically reduce the lifetime operational cost.
Still, I come back to wondering why iRobot brought out this specific model. New battery technology can and probably will be incorporated in newly manufactured models that have been around a while, such as the Roomba 880. So, we’ll have to dig further to solve the mystery.
Navigation & Vacuum Technology
iRobot continues to improve its already good navigation technology. Personally, I prefer the more regular pattern of a Neato. But there’s no denying that the more random method of the iRobot does work and works well. So, the improved ability of the Roomba to find its way around kitchen table legs, living room chairs, and much else is appreciated.
That goes hand in hand with the anti-tangle intelligence that prevents the 870 from sucking up your home entertainment center cords, drapery, and more. When the unit senses that, it reverses the rubber rollers. And, the ability of the cleaner to distinguish soft obstacles from hard does help the unit go under your bed skirts without a worry.
Ditto the enhanced ability to get closer to wall edges, a criticism I’ve had of the Roomba in the past. Now it will go right up to a kickboard, thanks to a long three-armed brush that juts out.
The Persistent Pass method – which senses dirtier areas and then focuses on cleaning them by repeated vacuuming – also gets a little tuning here.
Likewise, the AeroForce design change – rubber rollers rather than brushes, combined with under-body molding to redirect airflow – has increased the efficiency over previous generations. Here again though, the improvements incorporated in the new Roomba 870 are already found in the Roomba 880.
See the AeroForce “brush” system in action in this short 2 min video:
There’s nothing new about the bin. It’s adequate and easy to empty, but no size change has been made. The rollers are still as easy or difficult to clean, the difficulty level depending on your environment and patience, as they were before. As mentioned, the new AeroForce rubber rollers, and other components that did such a great job on pet hair have been around for a while now.
Similarly, the 870 still starts with a push and returns automatically to the recharging station. The scheduling method is the same. It provides the same “every day of the week” operation as before with easy-to-implement presses on the top buttons. Likewise, you can clean only certain rooms on set days at set times.
Virtual Walls, Lighthouses, And Hands-Free Operation
Similarly, many of the Roomba vacuum cleaners use Virtual Walls and/or Virtual Lighthouses to keep the robot from wandering out of or into unwanted areas.
The odd thing is – and it’s a partial solution to the marketing mystery – the Roomba 870 doesn’t work with the Lighthouse, only Walls. The 870 ships with two of the latter.
Why iRobot imposed the limitation is a mystery that may never be solved. Leaving out the sensors and electronics to work with a Lighthouse can’t reduce the manufacturing cost much. The daughter card on the main board that supports RF isn’t that big an expense. Perhaps the Walls are much cheaper to make than the Lighthouses.
The other form of hands-free operation – using the Remote Control – is a much more straightforward element of the solution to our puzzle. The 870 simply lacks one in the box. It’s available as an optional accessory.
Frankly, in my view, that represents no loss for the overwhelming majority of potential buyers. The 870, like every other Roomba, starts with a simple button push. Even scheduling is no complex effort. There may be a few physically limited individuals who could benefit significantly from the remote control. But for almost everyone else I suspect it’s just a geek’s toy. Not that I’m knocking that. I’m a geek!
The iRobot Roomba 870 is a definite improvement over previous models. And, happily, it’s about $100 less than the top of the line Roomba 880. It’s hard to fathom that the entire amount can be due to the lack of Lighthouse support and the absence of a remote control. Maybe Hercule Poirot will take up the challenge Whatever the solution to the mystery, it’s a welcome product offering.