In recent years battery-powered mowers have become a popular alternative to petrol mowers. As battery technology advances these mowers are going to become even more popular.And it’s easy to see why: there’s no more breathing in toxic fumes, driving to the petrol station or putting up with the deafening sound of an engine. But the main attraction is that you still retain the freedom that a petrol mower gives you. You’re not constantly looking over your shoulder checking that the cable is in the right position.The Bosch Rotak 43 LI Ergoflex is currently one of the best battery-powered mowers on the market and I got the chance to review it. During this review I’m going to share with you the good, the bad and who should consider buying it.

Bosch Rotak 43 LI Ergoflex Review - Specifications

ModelRotak 43 Li Ergoflex
Power36 Volt Lithium-ion Battery
Deck Size43 cm
Cutting ModesRear Bagging System
Cutting Heights20 - 70 mm
Number of Cutting Heights10
Grass Box50 Litre
Rear RollerYes
Weight13.8 kg
Guaranteed Best Price on Amazon

Bosch Rotak 43 LI Ergoflex Review – Key Features

  • Assembly –I would rate assembly on this one as medium difficulty. You’ve got to put together the grass box which comes in three different bits that you’ve got to fit together. Each of the sections has little clips that slot together. Focus on getting one or two of the main ones in first as this makes the rest of the task so much easier. You’ve also got to screw together the handle bar.When I was doing this I found that the holes are a tight fit for the screws (good in the long term) and you really need to apply some pressure when putting the screws in to make sure they go in all the way – it’s really important you do that!
  • Size and Build – With a 43 cm cutting swath this model is really designed at homeowners that have large gardens. The build quality is pretty solid but it is made of plastic. This may worry a few people for a mower of this price but I can assure you it is well made and it’s not just going to fall to bits like some of the cheaper plastic models. The main advantage the plastic construction brings to the table is that it remains lightweight.At the moment this is essential for battery-powered models as if a self propel system is implemented into the design (there are a few battery-powered models that do have self propel) it rapidly drains the battery, meaning lower runtimes. One thing I would comment on though is the window for the battery.This seems pretty pointless to me as you still have to open the window to actually check how much charge is left. Not really important, just my opinion really.
  • 36V Lithium-ion Battery – At the end of the day this is the number one reason anyone buys this model. Being powered by battery means no more cables and no more petrol. This one makes use of the newer lithium-ion battery technology as opposed to the older lead acid batteries.Lithium-ion batteries are much smaller, lighter and easier to use. When your mower isn’t being used the battery will retain any charge that’s left and charging only takes hours as opposed to days.
  • Ergoflex Handle – Bosch seem to be continually innovating in coming up with new features to try and make their products as ergonomic and efficient as possible. The idea behind the Ergoflex handle is that you can grip the mower in several different positions, finding the one that is most comfortable for you.It also means you can change position halfway through the task. If you’re mowing a large garden and holding on to the handle in the same position the whole time, it’s not uncommon to get cramp in your hands or numb hands – that’s happened to me quite a few times!
  • Grass Comb Technology – This is something unique that Bosch offer you. Trimming the edges of lawn has long been a problem. The traditional way of pulling out a strimmer or manual edger after you’ve finished with the lawnmower, is time-consuming and tedious.This mower has two bright red grass combs located on each side of the deck. The idea being that these will direct the grass at the edge of your lawn directly into the cutting path. Do they work? Find out further down the page.
  • Cutting Heights – Bosch supply you with one of the best, if not the best, cutting height selection on the market. You have 10 different positions available ranging from as low as 20 mm all the way up to 70 mm. That range destroys most of the competition.It’s not just the range that’s impressive either. The way you can just flip a single lever and set the mower to any one of these cutting heights in a matter of seconds is genius. In the past I’ve refrained from changing the cutting height on other models simply because it would have taken me minutes rather than seconds (yeah, I’m lazy).
  • Rear Roller – Rear rollers are a great addition to any lawn mower. Not only do they improve the quality of the finish but they also provide you with extra stability when you are going around the edges of your lawn and prevent the mower from digging in and scalping. Check out the performance section further down the page to see how this feature performed for me.
  • Grass Box – A lawn mower that is designed for large lawns obviously needs a grass box with a fairly big capacity. Well you get that with this mower as the grass box holds a whole 50 litres of clippings. This means you won’t be constantly stopping and starting every few minutes, which is good as that is really annoying!
  • Guaranteed Best Price on Amazon

Bosch Rotak 43 LI Ergoflex Review – How Did It Perform?

  • Cutting Ability – I used the mower on both wet and dry grass, which I think is important as it rains a lot in the UK (unfortunately). It performed great in both sets of conditions. It’s powerful enough to deal with grass that is slightly overgrown but you need to realise that the longer the grass is, the more effort it takes to cut, so the runtime you get will be lower.I’d also recommend that you bring the length of your grass down gradually – this is not only healthier for your grass but it also ensures that your battery performs at its best. I was pretty impressed with the lawn combs. They don’t provide a perfect, even finish around the edges but they do a much better job than any other mower.I still had to pull out the strimmer just to tidy the edges up, but I had nowhere near as much work to do. The only negative thing I could possibly say about the Rotak 43 Li’s cutting ability is that it only goes down to 20 mm. For some people that might not be short enough, but for the vast majority of people that just want to keep their lawn looking respectable, 20 mm is low enough.
  • Grass Collection – This mower packs the clippings nicely into the rear grass box. I didn’t experience trails or clumps of clippings and the grass box holds a decent amount too. When it comes to emptying it, you simply lift it off using the handle and dispose of the clippings. There’s not really much else to say it’s just efficient and easy-to-use.
  • Battery Performance – This is always the most interesting aspect of any battery-powered mower. Some of the ones I’ve used in the past have only provided me with a runtime of less than 20 minutes and have taken forever to charge up again.The first thing to note is that with this model you actually get two batteries. So you can always have a spare charged up and ready to go should the first one not be enough to finish your lawn. I was getting about 30 minutes runtime on each battery when I used it; so that gives you an hour runtime with both. Recharging the batteries only takes about one hour to one and a half hours, so you can definitely mow a large area of grass in a single day.When you’re mowing you can check how much charge is left on the battery by opening the window and pushing a button. Please, please, please remember that on the first 4 to 5 times you use the mower you probably won’t get the maximum runtime out of the battery.Each battery has to go through a cycle of charges before it performs to its capacity. I personally like these batteries as they are reasonably small, easy to charge up again and provide you with a decent amount of runtime.
  • Manoeuvrability – This is where durable plastic construction is awesome. The mower weighs less than 14 kg. Can you push 14 kg? For me it was pretty easy and required about 30% of the effort it takes to push a petrol mower. The lack of a cable also meant it was really easy to manoeuvre around the flower beds and trees it in my garden.
  • Ease of Operation – You might be thinking that this lawn mower sounds pretty hard to use because it’s got so many features – but you’re wrong! The Rotak 43 Li is one of the easiest mowers that I’ve ever used.Every feature it’s got is designed to save you time and perform as efficiently as possible. It’s easy to start, it’s easy to push, recharging the batteries and replacing them is a breeze and the grass bag does its job.
  • Lawn Stripes – Lawn stripes are basically created by pushing the grass blades over. For the blades to remain bent over they need to be pushed over with some force and weight. So the best lawn mowers for creating lawn stripes are those heavy cylinder mowers you see them using on bowling greens.Despite the fact that this mower is only a fraction of the weight of those mowers, it actually did a surprisingly good job. I was impressed with the stripes and it added a touch of class to my garden.
Bosch Rotak 43 LI Ergoflex Review – Who Should Buy This Mower?

Anyone that’s sick and tired of dealing with either a cable or all of the negative aspects of a petrol lawnmower should seriously look into battery-powered mowers.The cutting width and grass bag capacity on this particular model make it ideal for medium to large sized lawns. The fact that you get two batteries with this mower means you basically have one hour of consecutive runtime. Could you cut all your grass in one hour? If so then snap this one up because the quality of performance and the features you get are well worth the money. Oh, sloping lawns are also not a problem with this mower.

Bosch Rotak 43 LI Ergoflex Review – Who Shouldn’t Buy This Mower?

If you want to go green but only have a small garden then look at one of the smaller models in Bosch’s range. The 43 cm cutting width on this one would be too big.This mower is also not suited to people that don’t mow the lawn that regularly as grass that is too long will severely impact upon the runtime of the batteries, which will only leave you frustrated and angry – so if this is you, please don’t buy this model (or any other battery-powered model).If this mower sounds like it could be the answer to all of your lawn mowing needs, check out as they not only offer the best prices around but deliver it to your doorstep for free. Happy mowing! Guaranteed Best Price on Amazon