I have an Ericson 27’ sailboat that I am preparing to put an electric motor in and was wondering if there were any suggestions in replacing the seized Atomic 4 engine. What size motor, any recommendations on type or manufacturer and any recommendations on AGM batteries in the high Ah range?
Electric replacement for Atomic 4?
- Thread starter kevmann
- Start date
here's a selection 4 ur inspection.
no idea which one if any would be most suitable.
http://www.electricmarinepropulsion.org/Pages/Components_Motors.html
no idea which one if any would be most suitable.
http://www.electricmarinepropulsion.org/Pages/Components_Motors.html
Well, they would probably do the job but I would need to build or provide the motor controller. Has anybody seen an electric motor that comes with an integrated (?) voltage controller for the motor and wiring output for the control panel? All I have found are separate for all three components, motor, voltage controller and control panel that is usually custom for the job. It would be nice to have quality components that I know will work together without the guess work… Thanks for the input.
Drunkskunk
100 GW
those old Atomic 4s were rated for 18hp, right?
thats 13kw, but the way torque is applied on an electric, a 10kw would be more than enough for most of your needs.
Looking at the links above, the best motor of that group is the 16 kw, as it has the Motor controller designed for it as a package. assuming you would be using it to get in and out of the harbor, and manuver around the doc mostly at 1/4 power, that means you would need 4kw of power for 1 hour running time. unfortunatly, AMG batteries rarely can give more than 50 to 60% of there capacity when running a heavy load like a motor, so you probably need 8Kw of AMG for 1 hour running at 1/4 throttle. Assuming you choose a 12 volt 45 amp battery, then you will need 16 of them.
Depending on your needs, the 8 watt might be enough, and reduce the size and weight of the motor, but that won't reduce the size of the battery needed.
thats 13kw, but the way torque is applied on an electric, a 10kw would be more than enough for most of your needs.
Looking at the links above, the best motor of that group is the 16 kw, as it has the Motor controller designed for it as a package. assuming you would be using it to get in and out of the harbor, and manuver around the doc mostly at 1/4 power, that means you would need 4kw of power for 1 hour running time. unfortunatly, AMG batteries rarely can give more than 50 to 60% of there capacity when running a heavy load like a motor, so you probably need 8Kw of AMG for 1 hour running at 1/4 throttle. Assuming you choose a 12 volt 45 amp battery, then you will need 16 of them.
Depending on your needs, the 8 watt might be enough, and reduce the size and weight of the motor, but that won't reduce the size of the battery needed.
Lapwing
100 W
Way to go! 
Where and how will you use it?
Pretty sure for a 27 footer perhaps 8000lbs you can get away with a 5-10 KW motor. Depends on your expectations. I would recommend the Agni or the LEMCO. You might be able to get away with direct drive with the LEMCO LM 200 DM and 48V nominal, if you have a light weight boat. Avoid the German made PERM 132 . It gets to hot for sailboat use, and the same with the brushed Mars. The figure to look for is around 40-45 rpm per volt or lower for direct drive. The brushless Mars has too high a "volts to rpm" for direct drive. It is definitely doable if you get a reduction made.
Ideally a three bade feathering works best. Forget regen, unless you have deep pockets and go with Solomon. Controllers are the Alltrax AXE 48xx or the Kelley PM equivelent. The Alltrax will need a reversing contactor. Whats the budget?
Need a little bit more information. What is the biggest 3 bladed folding prop you can manage on the Erikson with about 2.5- 3 inches of clearance . If I remember rudder clearance is good. What is the prop shaft diameter. Do you use a conventional packing gland or a dripless. Lotsa questions.
Where and how will you use it?
Pretty sure for a 27 footer perhaps 8000lbs you can get away with a 5-10 KW motor. Depends on your expectations. I would recommend the Agni or the LEMCO. You might be able to get away with direct drive with the LEMCO LM 200 DM and 48V nominal, if you have a light weight boat. Avoid the German made PERM 132 . It gets to hot for sailboat use, and the same with the brushed Mars. The figure to look for is around 40-45 rpm per volt or lower for direct drive. The brushless Mars has too high a "volts to rpm" for direct drive. It is definitely doable if you get a reduction made.
Ideally a three bade feathering works best. Forget regen, unless you have deep pockets and go with Solomon. Controllers are the Alltrax AXE 48xx or the Kelley PM equivelent. The Alltrax will need a reversing contactor. Whats the budget?
Need a little bit more information. What is the biggest 3 bladed folding prop you can manage on the Erikson with about 2.5- 3 inches of clearance . If I remember rudder clearance is good. What is the prop shaft diameter. Do you use a conventional packing gland or a dripless. Lotsa questions.
dnmun
1 PW
kevman, not to turn you off electric conversion but you need to consider the reality of seaworthiness above just doing a conversion because you may need power beyond what the batteries can deliver in an emergency. do you know what seized on your A4 and had a machinist look at it? if the rod bearing, crank or shaft seized, you can have it ground down to undersized bearings (pretty common and not too expensive), seized from overheating usually is broken ring lands so new piston and rings would be simple. honing the sleeve you can do yourself, likely in place on the boat, but such a small motor would be easy to pull out, maybe.
what about a conversion of a transom mount outboard? run the skiff on it, SLAs for ballast. BOL, dm
what about a conversion of a transom mount outboard? run the skiff on it, SLAs for ballast. BOL, dm
Roy Von Rogers
10 W
Take a look at this site...
http://www.thunderstruck-ev.com/sailboatkit.htm
Roy
http://www.thunderstruck-ev.com/sailboatkit.htm
Roy
Ok... Yes the Atomic 4 I believe is around 14 to18hp (depending on model) and would need something around 14-20kw to resemble its useful range in power (depending on motor and its efficiencies or energy needs).
Usage would be in and out of dock off of North West San Francisco Bay with about 40min motor out and worst case about 1hour 20minuts back at worst. Some good currents coming back but sail should get me most of the way in.
I like the brushless motors coming out and am interested in a direct drive without reduction as I believe that energy efficiency is where it is going in this area. A controller with regen is a must as I feel that it would be useless not to have the power of the wind recharging the batteries and a wind generator would be a good idea for continuous recharge(wind dependent of course). I would also prefer not to have more than two main batteries with two backup cells looking at high quality 6v 250ah or perhaps 12v at around 100-120lbs each as I do not want to exceed weight of Atomic 4.
Thanks for the links! The Mars from Thunderstruck-ev.com is almost there, just the basic idea… I have about a 6 month window and would like to keep it under $2,500.00 unless I could achieve all of my goals would be willing to spend a bit more. Reason the A4 is going out (and not being repaired) is the noise/pollution/maintenance it produces/needs when it works. Electric has the ability to outperform it for what is needed as I am not looking to power across the bay but sail. Looking into prop sizes and information on its shaft, will get back on that…
Thanks again, more reading to do!!! I hope this answers my motivations and gives a better idea of needs.
Usage would be in and out of dock off of North West San Francisco Bay with about 40min motor out and worst case about 1hour 20minuts back at worst. Some good currents coming back but sail should get me most of the way in.
I like the brushless motors coming out and am interested in a direct drive without reduction as I believe that energy efficiency is where it is going in this area. A controller with regen is a must as I feel that it would be useless not to have the power of the wind recharging the batteries and a wind generator would be a good idea for continuous recharge(wind dependent of course). I would also prefer not to have more than two main batteries with two backup cells looking at high quality 6v 250ah or perhaps 12v at around 100-120lbs each as I do not want to exceed weight of Atomic 4.
Thanks for the links! The Mars from Thunderstruck-ev.com is almost there, just the basic idea… I have about a 6 month window and would like to keep it under $2,500.00 unless I could achieve all of my goals would be willing to spend a bit more. Reason the A4 is going out (and not being repaired) is the noise/pollution/maintenance it produces/needs when it works. Electric has the ability to outperform it for what is needed as I am not looking to power across the bay but sail. Looking into prop sizes and information on its shaft, will get back on that…
Thanks again, more reading to do!!! I hope this answers my motivations and gives a better idea of needs.
dnmun
1 PW
cncaddict has a big mars motor on sale here for $399 delivered, but the gear reduction you would have to develop. maybe you could develop a chain drive to the mainshaft behind the clutch and keep the rebuilt A4 in reserve in the bay.
i have neighbor here in portland who sails and crews regularly, running out to the islands for fun. my introduction to blue water was as crew on a freighter heading west under the golden gate over to vietnam, 1968.
so i would always put seaworthiness over EV, but they don't really conflict, and parallel hybrid should be possible if you need chain drive gear reduction. BOL, dm
i have neighbor here in portland who sails and crews regularly, running out to the islands for fun. my introduction to blue water was as crew on a freighter heading west under the golden gate over to vietnam, 1968.
so i would always put seaworthiness over EV, but they don't really conflict, and parallel hybrid should be possible if you need chain drive gear reduction. BOL, dm
Lapwing
100 W
$2500 is way to low a budget to do this right. If you go with AGM that $2000 possibly covers your batteries. You will need about another $3000 for the drive, controler and stuff, assuming you do all the installing.
You can do it for 1/2 of a new Yanmar and tranny.
You can do it for 1/2 of a new Yanmar and tranny.
If you are confident enough with your sailing/boat handling skills to head out onto the bay in your Erickson 27 with no motor at all, then consider a small, light, inexpensive electric drive system using the Mars Etek at only 24V with no reduction gear.
It looks to me like you would get 3 shaft hp output at 1350RPM while drawing 140A 24V.
For motors, controllers and info check out: https://www.kellycontroller.com
If 3hp will do it for you, then a $450 Mars, a $250 150A Kelly controller, and $400 for 4 golf cart batteries could get you almost an hour of electric power. 8 golf cart batteries would go for 2.3 hrs.
If you are looking to spend more and use higher performance batteries skip the $2000 worth of AGM ballast and go for Thunder Sky LiFePO4, they truely are high performance. I power my electric dingy with LiFePO4, they are superior to my old AGM battery in every way imaginable. ¼ the weight, ½ the volume, longer range, higher speed and they charge much faster.
Check out: http://shop.junglemotors.com
160Ahr of LiFePO4 would cost $2000 and be good for 70 minutes of run time at 140A. They are rated to do this for over 2000 cycles. Total battery weight would only be 100 lbs
$1500 would get you 4 big 6v AGM batteries rated at 300Ahr which would give a maximum run time of 80 min at 140A. They are only rated to do this for 350 cycles though, and weigh 370 lbs.
BTW 2:1 reduction and running at 48v would be the way to go for more power, and slightly higher motor efficiency. However 24V does allow you to run lots of off the shelf boat electrical stuff directly off your main battery bank, then you only need a small DC-DC converter to run chartploters and the like.
It looks to me like you would get 3 shaft hp output at 1350RPM while drawing 140A 24V.
For motors, controllers and info check out: https://www.kellycontroller.com
If 3hp will do it for you, then a $450 Mars, a $250 150A Kelly controller, and $400 for 4 golf cart batteries could get you almost an hour of electric power. 8 golf cart batteries would go for 2.3 hrs.
If you are looking to spend more and use higher performance batteries skip the $2000 worth of AGM ballast and go for Thunder Sky LiFePO4, they truely are high performance. I power my electric dingy with LiFePO4, they are superior to my old AGM battery in every way imaginable. ¼ the weight, ½ the volume, longer range, higher speed and they charge much faster.
Check out: http://shop.junglemotors.com
160Ahr of LiFePO4 would cost $2000 and be good for 70 minutes of run time at 140A. They are rated to do this for over 2000 cycles. Total battery weight would only be 100 lbs
$1500 would get you 4 big 6v AGM batteries rated at 300Ahr which would give a maximum run time of 80 min at 140A. They are only rated to do this for 350 cycles though, and weigh 370 lbs.
BTW 2:1 reduction and running at 48v would be the way to go for more power, and slightly higher motor efficiency. However 24V does allow you to run lots of off the shelf boat electrical stuff directly off your main battery bank, then you only need a small DC-DC converter to run chartploters and the like.
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