Originally Posted by KEALOHA
Thanks to every one; Alberto i will like to know more about the configuration of your system. I have a Thossa 7000 ht 48 v electric motor
I started evaluating electric over ten years ago when in need to repower
my previous sailboat. At the time nobody had solid information on range, reliability
, etc. I was not convinced by Solomon's Technologies at the time. ASMO Marine was just starting up, I exchanged a great deal of information with its owner and I was really impressed by him and his products (which got better over time), but nobody would anticipate (even guess) expected range. In the meantime we decided to sell the boat
and I installed a new diesel to make it more attractive (it worked, sold in two days).
After 10 years enduring a Volvo MD2B
in our "new" boat
, last year we decided to repower
with electric. The electric boats group at Yahoo was a fantastic source of information. I devoted a long time to research
all the options. In the end I decided to design and build my own system (some pictures in the member's galleries). Several reasons for this, among them the fact that what you buy as a "system" is only a part of the whole installation
, you need to select the batteries and charger
, their location, controls, meters, etc.
The system as designed provides lots of flexibility in case I have to make changes based on real performance. For instance, changing gear
ratio is easy, as well as system voltage, etc. Fortunately, none of this was necessary, the system worked flawlessly since day one. After over a year we never regretted the conversion, we would never consider installing a diesel again on this boat...
As for the system: brushed MARS (ETEK RS) motor
, Kelly controller (great product, it allows all sorts of programming by the user, and excellent customer support, they revised my design over and over), 72V system (AGM batteries), synchronous gears (2.4:1 ratio), QuickCharge charger
(it charges each battery
independently, with several available charge profiles), heavy duty solenoid, etc. I adapted the original throttle control and built a new instrument panel. The engine
room houses everything except the battery
charger, and also serves as a new, large storage
compartment given the smaller size of the system (more storage
where the fuel tank
was located). My calculation is that the whole system weights 150 lbs less than the diesel. Total cost was less that $4,200 (including some spares and miscellaneous items like a DC to DC converter for eventual house use, which I have yet to install).
What we love:
- Instant power.
- Quiet. Unbelievably quiet at low speed, a little humming at higher speeds.
- No diesel fumes/smell/smoke. No vibration.
- No maintenance (at some point, some years down the road, I'll have to replace brushes I guess). No more oil/filter changes, no more winterization, no more clogged fuel filters, no more bleeding lines, no more servicing injectors...
- Zero operating cost (we charge the batteries at the marina). No more stops at fuel docks.
- So far, completely reliable
- And... the looks of other people when we enter anchorages. We literally "glide" by, the boat is moving in complete silence and people already at anchor can listen to our music, eventually our conversation (as we can listen to theirs), and they stare at us because something is odd about this picture. It is so imprinted that they don't realize what is missing: engine noise! We love their stares
Finally, range. We kept the old two blade propeller
. It was inefficient with the diesel and should have been worse with electric, as three blades are recommended, but it has worked fine (to add insult to injury, the bottom has not been painted for a long, long time, which has a clear impact on performance). Last year we motored 13 nm at 3.6 knots in calm conditions and when arriving at the marina still had plenty of battery left. We motored 4 miles at 4.2-4.6 knots against 18 knot
winds for over an hour and again, plenty of battery left when arriving. Consumption
when day sailing
(leaving/entering the marina, eventually anchoring) is minimal, and the batteries recharge immediately. Charging
time when fully depleted (to about 40%) is between 8 and 10 hours. I guess that with a clean bottom and prop and low speed (around 2.5 knots) in calm conditions we could get easily over 20-25 nm (I'll confirm this soon, after hauling out for painting).
For the future: a portable generator for peace of mind while cruising for several days. I guess we will use it to recharge the house bank more than anything else.
We loved our boat. Now even more.