The 5 Best Electric Lawn Mowers for 2023
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Leigh Matthews is a sustainability expert and long time vegan. Her work on solar policy has been published in Canada’s National Observer.
Looking for a lawn mower that doesn’t contribute to climate change, and that won’t wake up your neighbor’s sleeping baby? We rate the best emission free, electric, lawn mowers on the market today, plus tips for buying the right electric lawn mower.
Gas lawn mowers degrade air quality
Think your choice of lawn mower doesn’t matter?
According to research published by Michigan State, “mowing the average lawn in the U.S. creates as much air pollution as driving the family car on a 200-mile trip,” which has many of us looking for greener options. We rated, and tested, emission free lawn mowers and listed our top picks below
The United States Environmental Protection Agency (EPA) places restrictions on emissions from lawnmowers, but there are no emission-free gas lawn mowers. Gas mowers also become less efficient and pump out ever-greater emissions the older they get.
As for electric mowers, these are tankless and instead rely on a cord or battery. Corded mowers have no mowing time restriction as they draw energy from your main electricity hookup. For battery models, battery time means how long you can use an electric mower before having to charge the battery again.
Most battery-powered lawn mowers are powered by lithium-ion batteries, which are just bigger versions of the lithium batteries in our laptops and cellphones. You can store a lot of energy in a lithium battery compared to older types of batteries, which is why electric lawn mowers are now possible and, indeed, comparable in power to a gas-powered lawnmower.
Unfortunately, lithium batteries are expensive and deteriorate over several years, with their capacity decreasing as the cells in the battery die off. It’s a good idea, therefore, to have a spare battery and to replace the battery every few years to ensure good performance.
Avoid second hand electric lawn mowers
Beware second-hand electric mowers with older batteries; the mower itself may be sold cheap compared to a new model, but the included battery or batteries may be next to useless and cost more than the mower to replace.
The best electric lawn mowers
Curious about how we rate products? Click here to view our methodology, which at its core, is about voting with our dollars to fight climate change.
Ego LM2102SP and LM2142SP [Staff Tested]
Highlights: 56V, Cordless, huge storage bag, headlights for evening mowing. Both models fold up easily for storage, have weather-resistant construction, and have a 21-inch deck size, with 3-in-1 mulching, bagging, side discharge options. Can buy with or without battery and charger.
- Same torque as a gas powered mower
- Huge collector bag
- Pin drop quiet while mowing
- Easy to store
- Can mow the lawn at night
The EGO 2102SP is a 21 in. 56-Volt Lithium-ion Cordless Walk Behind Self Propelled Mower that includes a 7.5 Ah battery and charger, and offers 60 minutes of cutting time and a 60 minute charge time.
With more than 6,000 5-star reviews at Home Depot online and a reputation elsewhere for high performance and usability, the Ego is a top pick for an electric lawn mower that can easily handle larger lawns.
You can also buy the 2102SP model without battery or charger for 450 (View Price on Ace Hardware).
This mower delivers the same high torque as gas-powered mowers without the air pollution and noise, and at a lower price! If your lawn area is half an acre or more, this monster of a mower might be your new best friend. It even boasts headlights, so you can do a spot of evening mowing should you wish.
One big plus for the Ego is that huge collector bag, which means you can mow a large area of lawn without having to stop to empty the bag. The downside here, of course, is that the machine becomes quite heavy by the end of your run. Happily, this model doesn’t seem to lose traction at the front when the bag is nearing capacity, unlike some other models.
The LM2142SP (View Price on Amazon) is a 2 x 5 Ah battery model that is very similar to the LM2102SP 7.5 Ah model. The 2142SP offers a bit more flexibility in handle height, however, with 6 handlebar positions available rather than just 3. This makes it the better option if you’re a bit taller or shorter than average.
One other major difference between these two Ego mowers is that the 7.5 Ah model has a polymer composite cutting deck, while the 5 Ah model has a steel cutting deck. Both seem to perform extremely well across all kinds of grass, but the steel is, arguably, the more sustainable material.
The rear wheels on the 2 x 5 Ah model are also an inch bigger in diameter (10 inches vs. 9 inches), which may help with maneuverability in some situations and be better for sloping lawns. The 7.5 Ah model also weighs a dash more at 78.8 lbs compared to 75 lbs or the 2 x 5 Ah model.
The major difference between the two, though, is simply the run time. The 7.5 Ah gives you around 60 minutes of run time before you’ll need to charge the battery. And, of course, while you’re charging the battery, you don’t have a spare to use as a backup. With the dual battery model, you can use one 5 Ah battery for 45 minutes while charging the other battery, then switch them out to carry on mowing without having to take a break. This way, you could pretty much mow all day and, thanks to the LED headlights, all night if you wanted!
Both of these Egos have one easy-to-use shifter style handle that adjusts the height of all four wheels at the same time, which is much more convenient than having to adjust each one individually. Both models fold up easily for storage, and both have weather-resistant construction and a 21-inch deck size, with 3-in-1 mulching, bagging, side discharge options.
The Egos also offer independent self-propulsion, meaning you can turn off the mowing function but still use self-propulsion to move the mower easily from one spot to another, such as over surfaces that could damage the blades if they were moving.
Finally, both the Egos have a 5-year limited warranty and, if you buy from Home Depot, a 90-day return window in case you’re not happy with your new mower.
Oh, and the Ego Power 56 Volt battery/batteries are shipped separately and are compatible with all Ego Power products. This means you can save on the cost of the mower by buying the tool only, if you already have an Ego battery and charger. Or, consider this an investment in the future of your tool collection if you’ll also be replacing any snow blowers, leaf blowers, hedge trimmers, chainsaws or so forth in the next little while.
One other reason Ego make my list of eco-friendly lawn mowers is their adoption of green power sources for their research and development facilities and industrial park. In 2004, the company installed a 7,500 square foot Green Roof system on their RD facility, with savings of around 1.5 gallons of gas per square foot each year. The roof of their Green Power Industrial Park also features a 2-megawatt photovoltaic power station.
This ‘Blue Roof’ generates, year-on-year, the equivalent power from burning 755 tons of coal. This cuts sulfur dioxide emissions by 50 tons and carbon dioxide emissions by 1677 tons annually.
In addition, the Ego Green Power Industrial Park utilizes ground-source heating, air-conditioning and water-storage technologies. They estimate that their ground source heating system alone saves 1 million kWh of electricity annually, the equivalent of 378 tons of coal. It also cuts sulfur dioxide emissions by around 25 tons and carbon dioxide emissions by 839 tons each year.
Ego hasn’t been in business quite as long as Black Decker, but they’re an innovative company with global reach. Established in 1993, they have long been invested in cordless electric technology and are now one of the world’s largest manufacturers of tools.
Our experience after one year of using the Ego electric lawn mower
After a year of hands-on use, here’s what a member of our team, Taylor, has to say about his experience with the Ego mower:
I’m not the type of person who really enjoys and looks forward to mowing their yard, unlike many of my neighbors; it’s a chore that needs to get done just like any of the others that are part of owning a home. With that being said, the Ego mower is hands-down my favorite mower that I’ve used to date.
2005 Victory Vegas 8 Ball SS Air Intake FMB Chopper Custom Drag Bars. 4″ straight rise, 2″ pull back Dead Creek Cycles Solo Swing Arm Bag Conquest Customs. Ground Pounder Exhaust Power Commander III USB Fuel Controller
Port Saint Lucie Florida Been riding for 21 years Previously Owned Bikes: Suzuki GS750E (1st Bike) Honda Aero 750 (2nd) Triumph Daytona 675 (3rd)
Luciferiad
Hmm. Didn’t even know HF sold powersport batteries.
So here’s the skinny: there are a limited number of battery manufacturers, and most like that battery was made by Johnson Controls or Exide or maybe Deka. I imagine as long as it meets the CCA rating for the bikes (310 CCA) it should be fine. Maybe find out who put the thing together before they stuck the “Thunderbolt” label on it.
You can call me Billy. Or Luci. But don’t call me Shirley.
Mine: 2011 Cross Roads, crimson red Lloyd’z ATS, IAV, VFC-III. Vic “High Performance” air filter. Ness Big Honkers. Funsies.
broggyr
I think you’d be OK as long as it’s not a Lithium battery. Several folks have had bad experiences with the lithium units. The HF Sealed Lead Acid should be OK provided it’s reliable. I didn’t see a CCA rating on the listing, however.
2013 XCT, Boardwalk Blue w/ Vicwrapz SS Cams, Lloydz filter ATS 3, PCV, UD pulley, Barnett clutch plates (no judder), Madstad Windshield, 5000K HID, TriOvals, Memphis Shields wings, Ultimate seat HyperLites, LED driving lights, Lloydz dyno 105H and 117T, Arlen Ness blinkers, KlockWerks KlipHanger bars, Avon grips Spectro Golden 4 20w40 for Victory L.SG424, Kury Sabertooth LEDs, THE FEW, THE PROUD, THE OBSCURE. TTWFO2
Bobbyd85
I may at times for certain things be frugal or cheap. But not on something like this. The placement of the battery if this were to become an unsealed part while riding down the road would cause a lot more than 30 worth of damage. I’ve had the stock battery for over 5 years without issue. I would say just buy a reputable battery and buy that one for your riding lawn mower. Just my opinion.
Also, our Yuasa batteries are the dry cell maintenance free aren’t they? Not Lead acid wet cell
“I arise in the morning torn between a desire to improve the world and a desire to enjoy the world. This makes it hard to plan the day.” 2012 Cross Country
Speedblue
Remember a bad battery is just a box to store old acid in. You got saddle bags, carry jumper cables. But it does suck when your battery goes on a bike. I like to go to Batteries Plus personally. Pay more maybe, but the batteries are usually good and I believe they have stores in numerous states now.
Buckeye, Arizona(USA) 2011 Victory Cross Roads, Black police bag guards, black engine guards, black handle bars, Triumph Tiger mirrors, Triumph hand grips, set speedo/tach back 5″. adjustable timing wheel, Lloyzz Fuel Programmer III air filter. Modified exhaust, made stock into 2 into 1. MRA windshield, Rotated front fender forward,relocated ignition switch, Bad Ace Fuel Tank Risers, Fat front tire.
Can I switch my deep cycle for a lawn mower battery to save weight?
If we just camp at sites with electric hookups and don’t boondock. can I swap my heavy deep cycle with a 20 lawn mower battery to reduce weight? Will the charging system work ok? Is that enough to run the electric brakes if the break away switch is triggered?
Super Active Member
It will work fine and I have recommended using a garden tractor battery to many people who have little need for a battery. It will have a shorter life and have less capacity than a larger deep cycle, but for the price it is a good choice for your use.
Super Active Member
The only thing I’d worry about is if your trailer has breaks would the smaller battery be able to fire them in a breakaway situation. If not it could make for a hazardous situation, as well as possibly illegal in some areas.
Super Active Member
The only thing I’d worry about is if your trailer has breaks would the smaller battery be able to fire them in a breakaway situation. If not it could make for a hazardous situation, as well as possibly illegal in some areas.
It does not take much power to energize the magnets in a break away situation. It only needs to engage the brakes while your trailer is going over the river and through the woods on its way to grandmas house. without you and your tow vehicle.
Desert Home
I live in the Arizona Desert, Southwestern USA. It gets hot here, and my power bills got out of hand. This is a journal of my various efforts to bring this problem under control using the cheapest technology I could find. Saving money shouldn’t cost a fortune.
Battery Charging (Harbor Freight item 42292)
Part 2 of this project is here and part 3 is here.
I have a tractor and two older quads in my barn. Yes, I have a barn. The problem is that about half the time I go out to use one of them the battery is dead. I drag out a charger and extension cord from the house, charge it up, and then get to use the vehicle; usually a day or so later than I wanted. All too often, I find out the battery won’t recharge and needs to be replaced. This is not only annoying, it’s darned expensive. And eventually I want to get a nice big portable generator with electric start; I really don’t want the battery dead on that when I need it.
Obviously, I need a float charger on the vehicles to keep the batteries charged. One that doesn’t boil the water out and can run unattended for months if necessary. I can’t find such a thing at a reasonable price. Yes, there are devices like the BatteryMINDer, Battery Tender, and hundreds of float chargers. These things can cost a heck of a lot if you need several of them for different machines that have a battery in them. Sure, it’s cheaper than replacing the battery, but you have to leave them plugged in all the time, and some of them just don’t work as advertised; if at all. Wouldn’t it be nice if there was a cheap little float charger that could be adapted to a solar cell? One that I could control the float voltage it puts out so I could use it on the AGM battery in one of the cars as well as the standard small lead acid battery in a quad? One that wouldn’t drain the battery if I kicked the cord out of the wall and didn’t notice until a month later? Such a device would run me at least 40 and I need several of them. Crap.
Looking around, I found a coupon for the Harbor Freight float Charger, but it has some draw backs. It will drain a battery if it is unplugged from the wall, it puts out too much voltage to be left alone essentially forever, and the stupid wires on it suck. But, it also has some compelling positives, it’s cheap, it has a DC wall wart for power, it’s cheap, it has simple circuitry that can be modified to do what I want, and it’s cheap. The DC wall wart is expecially attractive since it can be cut off and a solar cell substituted to run it where there is no power. So, credit card in hand, I went to Harbor Freight and bought several of them (I did mention they were cheap didn’t I?).
First inspection showed me that the little devices are set to 14.1 volts constant voltage with a current limit of around.9 Amps, it will discharge a battery through a status LED, and the combination of thick clumsy wires with smaller power wires is somewhat hard to deal with. Time to take one apart and see what’s in it. After prying on the cover for a while unsuccessfully, I gave up and cut it open with a Dremel. Reverse engineering it gave me the schematic below:
So, it has a good old 7805 power regulator set up as a variable supply and a TIP41 transistor to regulate the current. The S9013 transistor is set up to turn the device off around 9V, because a 9V lead acid cell is probably beyond recovery for a float charger. The resistors in parallel are to get a specific value out of the various dividers in this thing. My first question was, “Why do it this way instead of a variable resistor?” The answer was obvious when I checked the of the various components; fixed resistors cost a fraction of a cent in quantity, variable resistors are much more expensive. But, the question I don’t have an answer to is why they didn’t put in a diode to stop from discharging the battery if it’s unplugged from the wall? Oh well, I have a few (hundred) diodes laying around that can do this job for me.
When I cut open a second one I found a different set of components. The second one appeared to be an older version and did not have the parallel resistors. It had one resistor in each position and was laid out slightly differently. The circuitry was essentially the same, it just appeared to have been changed over time. Same drawbacks and advantages as the first one.
So, I hooked one of them up to an AGM battery I have in my car and let it work for a few days. Sure enough, it float charged the battery up to 14.1 volts and kept it there. This is not a good thing. The specs on the Optima AGM automobile cranking batteries warns against this and tells me to keep it between 13.2 and 13.8 volts. A little rework should take care of this problem; especially if I add a diode to the output which will cut.7 volts off the top and get me right in range. It also appears that I can set the voltage by adding a simple little potentiometer and setting it to be what’s needed for a normal lead acid battery like my tractor. This would be really useful since the instructions for float charging a lead acid battery vary by each author I look at.
I’ve seen instructions that insist I shouldn’t charge a flooded lead acid battery to more than 2.1V per cell for a 12.6 volt float. Then when I look at another site it says the float voltage should be 2.2V per cell which gets me up to 13.2 volts float. Then, they start talking about surface charge, waiting 24 hours to check it, parasitic current draws from onboard devices, and temperature corrections. Then some of them talk about how as little as one tenth of a volt will shorten the life of the battery considerably. Obviously, many of these people are spouting off stuff they don’t understand and others are just repeating things they read on some forum somewhere. What to do? I’m just going to start with the info from Wikipedia and see how the water in the battery holds up. I’ll set the AGM voltage at 13.5 and the flooded cell batteries at 13.9 for a month or so and see how much water goes away. I’ll adjust down if the flooded cells lose water. Note that using a constant voltage supply will take care of parasitic devices like the little LED that blinks for the alarm system on my car. That’s why I prefer constant voltage with current limiting techniques.
Harbor Freight Announces New Atlas Brand Of OPE Powered By A Dual Voltage 40V / 80V Battery
I got my Harbor Freight catalog for February the other day and spotted the new Atlas OPE lineup featuring a dual voltage 40V / 80V battery and several outdoor tools. This is interesting as Harbor Freight has had their Lynxx line of 40v tools for a couple years, and has recently released a few OPE tools as part of the Bauer 20v system. It’s a bit odd that they’re also introducing another brand that features a dual voltage battery that overlaps the 40v category.
My thoughts: This looks to be another good, better, best scenario from Harbor Freight like we’ve seen with many of their other new brands, as it caters to users of all price ranges and applications. These new OPE options from Atlas look to be in the Best category as they’re running the highest voltage and assumably the most power of any Harbor Freight offerings.
In the catalog they show an 80 brushless blower, 80v brushless 18” chainsaw, 80v brushless self propelled 21” mower, and an 80v 16” string trimmer (motor type unknown, the catalog image isn’t clear enough to see if it says brushless).
In addition Harbor Freight has a separate landing page on their website for the Atlas OPE tools and shows 2 other tools which appear to be 40v, including a hedge trimmer and a pole saw, although it’s not listed if they’re brushless or not and there’s no other info at this time. The 80v tools have a couple specs for each one and they’re quite good and should do well in competition with other major brands.
The 21” self propelled Brushless more features a steel deck, brushless motor, and claims to get 65 minutes of runtime which is pretty good and should be enough to mow most residential yards on a single charge.
For the 80v brushless blower it features an impressive 605 CFM at 105 MPH as well as a brushless motor and a cruise control lever.
On the 80 brushless 18” chainsaw, it features an 18” bar and chain, brushless motor, and claims to get 140 cuts through 4×4 on a single charge. It also looks like it has metal bucking spikes as well as a kickback break, which aren’t that common yet on cordless saws so hopefully that’s the case here.
For the 80v string trimmer it features a 16” cut width, bump feed head, and accepts up to.095 line which is better for heavier trimming. In terms of batteries, they only highlight the dual voltage 40/80v model, but on the 40v hedge trimmer we can see another, smaller 40v only battery.
This leads me to believe they’ll be rolling out a dedicated line of 40v tools that can use the dual voltage battery much like the DeWALT FlexVolt or the Hitachi/Metabo HPT/Hikoki Multivolt, except these are the first OPE tools I’ve seen to use this technology.
Whether or not they continue to carry the Lynxx 40v tools remains to be seen, but it should be interesting. Overall this is very interesting and should compete well with major brands if the performance is as good as they indicate.
According to the catalog, these Atlas tools should be hitting the market sometime in March of this year (2020).
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Комментарии и мнения владельцев
not impressed with 22 inch hedge trimmer 40v battery. The battery lasts less than 30 minutes and when you go to recharge shows error. maybe just a bad battery but being 2 hours, one way, from nearest harbour frieght makes it difficult to return. Left on charger four hours lasted 20 minutes next time and still not finished with job.
I’ve watched some videos regarding their 80V and 40V chainsaws, and there seems to be an issue with the 80/40 batteries. Even though the indicator light shows a half charge, it doesn’t seem to want to work properly. Some think it might be an over heating issue, but others have said the batteries themselves didn’t seem warm enough to support the claim. Some think it might be an issue with the battery’s ability to read the charge properly. I haven’t seen any videos where a standard 40V battery is being used, so I’m not sure if the problem also exists with those batteries too. Have you heard any issues with the 40V batteries not using a full charge? Thanks in advance.
Well Harbor Freight has done it again, as a faithful customer they have chosen profit over customer service. Last year they discontinued and attachment for one of their aluminum floor jack brands that allowed you to have a wider area to jack up your vehicle. Tried to buy the last one my store had but was not allowed to because even though it was available they had not formally announced the discontinuing. Sent email to customer service and they did respond but it took over 3 months for the “process” to take place so I bought a competitors and modified it to work. Now with 3 Lynxx blowers, 1 weed eater and a polesaw less than 1 1/2 yrs old. I’m stuck with products I can’t buy part’s for. I’ve been on both sides of the buisness world and there is no reason they cannot have their supplier’s make at least batteries that are interchangeable. Sad that a company many people rely on and can’t afford high dollar equipment for their needs are put behind profit.
Harbor freight lawn mower battery
Harbor Freight Tools at 800-444-3353 Monday through Friday from 8:00 a.m. to 4:30 p.m. PT, email at recall@harborfreight.com or online at www.harborfreight.com and click on “Recall Safety Information” on the bottom of the homepage for more information.
This recall involves two models of 14 inch chainsaws sold under three different brand names. The Portland and One Stop Gardens brand chainsaws have a green and black color scheme and “Portland” printed on the blades. The Chicago Electric brand chainsaw has a red and black color scheme and “Chicago Electric” printed on the chainsaw handle. All recalled chainsaws were sold with a black blade guard. The model number is printed on a label on the bottom of the chainsaw.
Consumers should immediately stop using the recalled chainsaws and return the product to their local Harbor Freight Tools store for a free replacement chainsaw. Replacement units will be available starting May 21, 2018.
Harbor Freight Tools has received 15 reports of chainsaws continuing to operate after being turned off by the operator, resulting in three laceration injuries including one serious injury to the arm requiring stitches.
Harbor Freight Tools stores nationwide and online at www.harborfreight.com from May 2009 through February 2018 for about 50.
Harbor Freight Tools, of Camarillo, Calif.
Note: Individual Commissioners may have statements related to this topic. Please visit www.cpsc.gov/commissioners to search for statements related to this or other topics.
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The docking station’s printed circuit board can short circuit when exposed to moisture, posing a fire hazard.
The insulation coating on the stove can ignite during use, posing a fire hazard.
The fin scroll of the chipper shredder can fail, ejecting pieces of metal from the chipper shredder hopper during operation, posing a laceration hazard.
The U.S. Consumer Product Safety Commission (CPSC) is charged with protecting the public from unreasonable risk of injury or death associated with the use of thousands of types of consumer products. Deaths, injuries, and property damage from consumer product-related incidents cost the nation more than 450 trillion annually. CPSC’s work to ensure the safety of consumer products has contributed to a decline in the rate of injuries associated with consumer products over the past 50 years.
Federal law prohibits any person from selling products subject to a Commission ordered recall or a voluntary recall undertaken in consultation with the CPSC.
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#7 Geo.
We use a 30 Tractor supply mower on the sail boat to run the lights, GPS, speedo. depth and radio. When not in use I connect a 20 Harbor Freight watt solar cell to charge it. Off season I keep it on a trickle charger and use it to drive the CGEM. Lasts about three years.
#8 johnnyha
I use small 8AH and 5AH batteries as weights on my dob, the 8AH lasts about 8 hours with AN/Servocat tracking and with a small brushless fan running. And the 5AH sits in the tripod tray and runs my EM200 all night.
#9 Geo.
Sorry to say you have to take battery AH claims with a grain of salt. They are often inflated, particularly if they are of Asian origin. Good discusion here:
#10 avarakin
I built a battery pack out of 25 tractor battery from walmart. It is of size U1 which supposed to give about 30AH. I use it for imaging. laptop, mount, camera. About 2-3 amp in total. It lasts about 6 hours. I have it for couple of years and so far so good.
#11 Calypte
I use a lawn mower battery from Pep Boys. I’m on my second one. The first died after about 10 years. When I bought the first one, the guy asked what I wanted, and I told him, “For a telescope.” I usually try to evade that question, because most people have no idea what you’re talking about (e.g., “Why do you need a battery?”). But the clerk said, “Oh, my brother has a telescope, you need this. “
#12 ubermick
Was wondering too how you estimated 1 amp for your dew heater(s)? According to Kendrick, their OTA strips pull about 1.5 amps per hour for an 8″ OTA, and another quarter amp or so each for things like eyepiece heaters. (Think 12v fans are fairly nominal) I just finished building my own out of nichrome, and am assuming I’ll need 4 amps an hour (granted that’s powering my mount as well, a Celestron CG5-GT, which pulls something like 1.5a when slewing, and a little under half that when tracking)
I bought an 18ah mobility battery from teh intrawebz (Amazon) for 35 shipped, and quickly realized it wouldn’t be enough, so ended up ordering a second and wired it in paralell. This (supposedly) gives me 36ah, but as mentioned above, we’re talking cheap Chinese batteries. I’m assuming probably closer to 30ah. I never want to drop this below 50%, so my power pack will give me about 5 hours of observing time. Not exactly a lot.
Long story short, the rule of getting at least double what you initially think you need is a good one, and I’ll probably end up building another tank with a 125ah marine battery in a few months when the temps drop and the nights get longer.
#13 C_Moon
Was wondering too how you estimated 1 amp for your dew heater(s)? According to Kendrick, their OTA strips pull about 1.5 amps per hour for an 8″ OTA, and another quarter amp or so each for things like eyepiece heaters. (Think 12v fans are fairly nominal) I just finished building my own out of nichrome, and am assuming I’ll need 4 amps an hour (granted that’s powering my mount as well, a Celestron CG5-GT, which pulls something like 1.5a when slewing, and a little under half that when tracking)
I estimated based on this chart on the scopestuff website (near bottom of page). I was looking for a 2″ EP and a 0.965″ EP (both for my finderscope). According to those charts, the draw for both is 0.53 amps.
I was uncertain about the fan, but recall somehow estimating the secondary heater as being in the ballpark of the dew strips.
I’d be interested if there are better ways of estimating how many amps these things will draw.
#14 Billydee
Yes, Use a 12V AC power supply and hook each item up to it (one at a time) and place a DC amp meter in series with the item and PS. The meter will give the exact amp usage for that one item. Then after you test all items you can add them up and you will have the exact need for a 12 volt battery. Since most 12 volt batteries are a little higher in voltage you will use less amps but exactly the same watts. Once you buy your battery you can charge it and run the test using the same method. If you want you can run the test using your car battery. The amp meter can be purchased at Harbor Freight for about 5.00. A four item test should take you about 10 minutes.