I figured I'd start a thread to share and document the electrical
re-fit/upgrade my co-owner at myself are doing to our 1973 Ericson
27. When complete, she will have a 460AHr LiFePO4
, a Victron 2kVA Inverter/charger, and full remote
monitoring/telemetry of the system.
herself is a 1973 Ericson
27. She was originally sold
with outboard propulsion
, but was upgraded to an inboard Diesel
(Yanmar 1GM10) in 1983. Since then, she has been lovingly maintained, and lavishly upgraded. These upgrades include hot & cold pressurized water
in the galley
, as well a properly refrigerated ice box, using a Dometic CoolMatic conversion kit. We've also put in modern electronics
, tiller-pilot, AIS
, and modern VHF).
Unfortunately, her electrical system
hasn't really kept up. Until this upgrade, she had a pair of 90AHr Flooded deep cycle batteries
for both starting and house loads. With everything that's been installed, we now consume about 50Ahr/day even when we're trying to be careful.
When thinking about what we wanted on the boat, our reference trip that we wanted to be able to achieve was a week long trip from Vancouver
to Princess Louisa Inlet, where we could spend 3 to 4 days at the dock
in PLI, without having to run our engine
to recharge. As my co-owner and myself get into our early 40s, we're also starting to appreciate more and more creature comforts.
Based on this, we put together the following set of requirements:
- Enough storage to run reasonable loads for 4+ days.
- Easy access to AC power.
- Ideally allowing the use of a small induction cooktop on shorter trips.
- Full integration of all components
- Remote monitoring of the system when not aboard
- Rapid charging of the house bank when the engine is running
- But also control so that a large alternator doesn't overwhelm the 1GM10
The new house battery will be a DIY
battery. It will be built out of 230AHr EVE cells, in a 2p4s configuration. The battery itself will be managed by a REC Active BMS. The battery itself will be in a compression
frame, and strapped down/protected to ensure its safety
protection will be provided by a 400A Class T fuse.
We have selected the Victron MultiPlus Compact 12/2000-80 for this project
. Initially because it was the smallest 120V/60Hz inverter/charger that Victron makes, but afterwards, we realized that it's enough power to a) run a single
burner induction cooktop, and b) it can be used to run our hot water
tank if we so choose. The power-boost functionality of the unit also lets us plug
into our friend's dock
power, which tends to trip the breaker if you draw more than 10A from it.
High Side DC System:
What I refer to as the "High Side" DC system consists primarily of the Inverter/Charger, and the other charging
sources (Solar + Alternator). These systems will connect through a Victron Lynx Distributor. The power from the battery is controlled through a Blue Sea Systems 7713 remote
battery switch. This will allow the REC BMS to drop the charging sources if something goes wrong. Because this is unlikely to ever be tripped, as all the charging sources are controlled by the BMS (through Victron's DVCC functionality), I didn't want to spend the continuous power required to keep a normal contactor closed.
Low Side DC System:
The low side of the system is basically what amounts to the current
DC loads on the boat. We will be tidying up the wiring
using a Blue Sea SafetyHub 150 as a DC distribution power. BMS control over the load side will be through a Victron BatteryProtect 65, which provides more than adequate current
handling for our DC loads.
Because we're telemetry geeks, our DC loads will be monitored using a Victron SmartShunt configured for Energy meter mode. This will also allow the DVCC function to properly account for DC loads (such as the ice-box, or USB chargers).
Alternator & Regulator:
Given the size of our battery, we quickly came to realize that the stock alternator
on our 1GM10
wasn't up to the task. It's a nominally 35A Hitachi alternator, which realistically means it can probably pump
out 18A continuous. By the same token, we also recognize that our 40 year old 1GM10
has all the power of a geriatric squirrel. As such, we started to look at our options.
In the end, the solution we have chosen is to go with a Wakespeed WS500 regulator
, driving a modified 85A Hitachi alternator. We chose the Wakespeed as it will fully integrate with the REC BMS, allowing the BMS to control the current output from the alternator. It also has a number of features that allow us to control how much load it is putting on the engine.
The configuration plan is to have the regulator keep the alternator essentially idle below about 1200rpm. This will keep the drag on the engine minimal when we're at idle and/or putt-putting around in the marina. From there, it will ramp
up to full power. The other feature we intend to add is a toggle switch that will allow us to cut the alternator output in half (or maybe more) when we flip it, basically a "more power" switch.
Lastly, the Wakespeed will communicate over the CANBus, communicating with both the Victron and REC equipment
to manage the power, and also pumping NMEA 2000
data out which we can pull in from our instruments
The alternator itself is an 85A Hitachi that was given to us. We had it rebuilt by a local alternator shop, and had them modify it for external regulation. While working on it, they replaced the bearings, and rectifier, and did a general cleanup on it. Beautiful work
for $180 or so.
When we do eventually re-power (probably to a Beta Marine
16 engine), the Wakespeed will be transferred to the new alternator/engine.
Given her small size, and that she's rigged with all lines leading to the cockpit
handed sailing), there isn't much room for solar
on board. That said, we're adding a pair of 24V, 60w solar panels
to the top of the dodger
. It's not much power, but will hopefully at least make up for all the instrumentation if shore power
goes away. The two solar panels
will be wired in parallel (as one is likely to always be shaded by the boom), and will be controlled by a Victron MPPT
Down the road, we may pick up a foldable/portable solar panel (Bluetti SP200 or similar) that we can deploy while at anchor
or at the dock.
Engine Starting System:
One of our early choices was to keep the engine starting system separate from the house battery. This is largely due to a concern related to the extremely low internal resistance of LiFePO4 cells, and how that might play with the starter motor/solenoid. As such, we have chosen to stick with an inexpensive group 24 starting battery for this purpose.
The battery itself will only be used to start the engine. It will be maintained by an Orion TR 18A DC
, and monitored by a Victron BMV-712. Furthermore, the Orion TR itself will be controlled via its on/off connector using the relay in the BMV. The idea of the latter is that we can better control when the Orion is operating. It's internal "alternator detection" is unlikely to work
well directly off of the Lithiums due to their flat voltage curve.
Monitor & Control:
At the core
of our system will be a Victron Cerbo GX. It will be used to monitor
the entire power system, as well as other boat sensors. The BMS, Alternator regulator, Inverter/Charger, shunts will all communicate through it. We will also use it to monitor
tank levels (especially fuel
and the holding tank), as well as monitor & manage our bilge pump
As our marina doesn't have WIFI
, it will get connectivity to the outside world via a Netgear Nighthawk LTE router. This will allow us to remote in and check on the boat as required.
AC Power System:
One of the other goals of this project
is to bring our AC power system up to what I would consider relatively modern safety
In our lazarette, we will be adding a weatherproof box holding both a galvanic isolator
(Promariner FS30), and an ELCI breaker (ASI 32A 120v DIN rail breaker). This will then wire directly to the Victron Multiplus. A second, output breaker from the Multiplus will in turn feed a 3 circuit distribution panel.
So yeah, this is a big project for a small, old boat. But she's a good boat, and we like her.
Now that I've written this all down, my plan is to diagram up each of the sections above, and add these diagrams to the post.
As we build out the system over the next several weeks, expect more posts on this thread, along with progress photos.