What is it?
Your bike's tyres are the only two contact points with the road (or gravel), so making sure they're pumped up properly is vital. That's where a good bike pump comes in, while if you're out riding they're an essential accessory in case of a puncture or loss of pressure. In the past, cyclists have packed a hand or mini pump with them, or if you're really conscientious about weight and speed, CO2 canisters. However, the last couple of years has seen a new type of pump appear - the electric pump.
While there have been numerous electric bike pumps appear on the market in this time, a lot have not always come from established brands, but the arrival of the E-Booster Digital electric pump from popular bike accessory brand Topeak has really caught the attention of a lot of riders.
Priced at £99 (though you can probably find it for a bit less) This compact electric bike pump fits both Presta and Schrader valves and features a backlit LCD display, with three pressure modes to toggle between: PSI, BAR or KG/CM2. It promises to inflate a tyre to 80PSI in 50 seconds and will pump a tyre up to 120PSI. Along with the pump itself, it also comes with an additional extender hose if you're using TPU inner tubes to avoid the risk of overheating damaging your tube. Again, this extender hose comes with connections for both Presta and Schrader valves.
Charged via USB-C, the battery is good for 3 x 100PSI inflations, or 4 x 80PSI inflations (for 700 x 25c tires), while mountain bike riders can expect 4 x 30PSI inflations if running 29 x 2.35 tyres. Finally, there's a silicone case supplied to protect against overheating, and when not in use you've got the choice of a storage bag or waterproof pouch to keep it safe during your ride.
What it's like?
Out of the box and the first thing that strikes you is its compact size. Measuring 5.9 x 3.5 x 8.6cm and weighing 162g, it's a neat little thing that easily slips into a rear pocket on a cycling jersey or side pocket on some MTB/gravel shorts.
While it comes partly charged, you might want to give it a quick top-up before setting off to ensure its fully charged. When you do need to use it for the first time, it couldn't be easier - push the power button and the display lights up. It's at this point you can preset the pressure - all you have to do is hit the plus or minus icon to toggle to the desired pressure.
It's then time to put some air in your tyre. Whether you're running bikes with Presta or Schrader valves (or you might have bikes with both), it's nice and easy to swap between the two thanks to the selector switch on top of the unit. Flick it to the valve you're using than then place the head over the valve before hitting the power button. The pump will then spring into action and inflate your tube - you'll be able to see the pressure increase before it reaches your desired pressure. A quick tap of the power button will stop the pump. It is pretty noisy - something you might not expect from such a small unit, so you might want to avoid inflating your flat tyre outside someone's house on an early morning ride. It's also quick - taking less than a minute in most cases, though some tyre and pressure combos will take a bit longer. Even with a good hand pump we reckon you'll be still going long after you've popped the E-Booster back in your pocket. 
Should I buy one?
Some people might look at electric pumps and will argue that 3-4 inflations is pretty limiting when out on a ride, but unless you're very unlucky, have you ever had three punctures on your average ride?
Whether those kinds of odds will rest easily will depend on you, but if you do reckon an electric pump is for you, then the Topeak E-Booster is a great choice. Easy and quick to use, it's a great piece of kit for cyclists that ensures your tyres will always be at the right pressure.
