Upgrading the Electric System on Jean-du-Sud

Jean-du-Sud‘s energy needs are based on two underlying ideas: long offshore passages and a skipper who needs Starlink for work. This translates into a budget of roughly 220 Ah per day, assuming two average power demanding persons onboard.

Currently, Jean-du-Sud does not have the capacity to meet such demand. Assuming the products onboard were new, the current design would yield roughly 54 Amphours (Ah) of storage and roughly 80 Ah/day of solar capacity. This analysis further neglects the fact that solar panels are currently directly connected to the batteries, hindering battery life, or that all batteries are being directly connected to the (former outboard) alternator and the load. All of this to say that a supply side upgrade is in order.

The upgrade will increase the solar panels size to 400 Watts (160 Ah/day), the ability to use the engine to charge batteries when needed, the use of an inverter charger for modest 120 Volt (V) needs onboard, but more importantly to be able to connect ashore when there is shore power available. It also aims at isolating battery banks with different chemistry.

Design

The chosen design is inspired from James Frederick’s SV Tritea. James has commercially endorsed Renogy products in his early videos (2022-a) and then switched to Dakota (2022-c). So to be specific, the design for Jean-du-Sud is partly based on « Reno-James » for solar panels (image above), and « Dako-James » was a starting point for the circuitry. The 2022 video is quite useful for the nitty-gritty details of wiring and circuitry (image below).

Alternative designs exist, most prominently the installation of solar panels on the dinghy davit rather than on the side (e.g. Huub and Daniela, picture on the left below, and Abroad Reach Travel). Jean-du-Sud‘s current installation also influenced the design (picture on the right below).

The sketch below summarizes the circuitry design. Three solar panels will be installed, two Renogy 200 Watt (W) panels on each side of the cockpit, and one 100 W panel, already installed, will remain installed aft, behind the cockpit. The physical modifications required to support the side solar panels will be based on SV Tritea’s guide. The wind turbine will be replaced by an AIS and a Starlink Antenna fixation point. The solar panel midship will yield the occupied space to another (unrelated) install.

The two 200 W panels will be connected in parallel to a single Maximum power point tracking (MPPT) charge controller, itself connected to two new 100 Ah lithium phosphate batteries and the demand side of Jean-du-Sud’s interior. Each panel’s circuitry will be protected by breakers that can be manually triggered, allowing to isolate the panels if needed.

On the demand side, the sole exception to the connection is the windlass, who will remain connected to the engine battery. I have experienced « smart isolators » on other sailboats, preventing the use of the windlass unless the engine is running, and I hope to find how such feature is achieved (suggestions welcome).

The house batteries will be connected to a 2000 W inverter charger, which will manage shore power and 120 V electricity produced from the batteries. A 2000 W inverter is overkill. I do not think that more than 200 W of 120 V power is needed (mostly laptops and a Starlink antenna). However, inverter chargers of 2000 W are the smallest on the market. I was also advised to leave room for « future upgrades ». Future me may thank me, but Current me finds the 2000 W inverter expensive.

The remaining 100 W solar panel, installed aft, will be dedicated to the engine battery. When an engine start is required on a whim, it is usually because it is critical for safety. The solar panel thus acts as a safety charging measure. It will be connected to a MPPT charge controller integrated to a Dc to Dc charger, allowing to connect the alternator and the solar panel to the engine battery. The DC to DC charger further allows to charge the house batteries on a different voltage (thus protecting the chemistry) if the engine battery gets full while the engine still works.

I pondered on installing a second MPPT charge controller, one for each solar panel, as a measure of redundancy and for optimizing the current delivered to the batteries. However, such approach was discouraged by a Renogy expert. Since there is already an MPPT charge controller on the DC to DC charger, there is redundancy onboard. The DC to DC charger (or the other MPPT) can be rewired to accommodate an emergency.

I also pondered if an additional battery would be required. On Jean-du-Sud, batteries are installed on an elevated plate in the bilge, below the floor. There is room for an additional one right next to the others. Since the upgrade could be done at a later point, I decided to test the current design prior to an additional purchase.

Brands and Costs

I explored Victron, Dakota and Renogy products. I chose Renogy products because of their lower price (see the table below). That sums pretty much the shopping and purchase decisions. Total estimated costs are at 3699, including a 1000 CAD estimate for additional wiring.

This total is actually more than I paid. I started purchasing products in December 2023, allowing me to benefit from Christmas specials (!). In particular, I paid less for solar panels and the MPPT charge controller. Furthermore, the Christmas specials came with additional gizmos, most notably a Bluetooth connector for monitoring the systems.

If someone plans its design before holidays, it is possible to save more. I did not, and Jean-du-Sud was buried in two feet of snow at the time of the purchase. Hence, I only bought the material I was certain I would need, deferring the purchase of the Dc to Dc charger and the inverter/charger. At the time, I was thinking of keeping the two battery banks completely separated. I was also trying to avoid 120 V on the boat.

Installation Time

Given that for the engine install, it took me three times the time I had estimated, I will refrain from estimating anything at this stage. I will update this section once the installation is over to discuss the real installation time.

Conclusion

I anticipated that the electricity upgrade was going to cost more. On the scale of a sailboat, it is expensive, but not as expensive as installing an engine. Overall, this is not bad.

The battery bank allows for 200 Ah with the new installation (maybe less, given the charging time of the last 20%). I estimated 230 Ah as a daily need, perhaps requiring an additional battery for capacity, but I can also see how things may change on the demand side of electricity.

I recently switched my electronics habits, using a slow CPU laptop with me, cloud-sourcing my power intensive calculations, and using the cell phone rather than the laptop when I can. These habits replace a (power hungry) MacBook. I may furthermore replace the radar installed on Jean-du-Sud, a power hungry model of the 80’s. Those are options in the air, but in the short run, the deck, the hull and teak are in a dire need of attention, so these ideas will have to wait.

References

Abroad Reach Travel (2021). 600W of Solar on A 30 Foot Sailboat?, YouTube video retrieved online in May 2024 at this address.

Dakota Lithium Batteries (n.d.). Our Batteries, document retrieved online in May 2024 at this address.

Huub and Daniela (2023). Hauling out the boat – let the projects begin…, YouTube video retrieved online in May 2024 at this address.

Renogy Canada (n.d.). Products, document retrieved online in May 2024 at this address.

Sailing Tritea (2022-a). Installing New Renogy Solar Panels on Triteia: Doubling Our Solar from 200 watts to 400 watts!, YouTube video retrieved online in May 2024 at this address.

___________ (2022-b). SV Tritea Custom Solar Setup, document retrieved online in May 2024 at this address.

___________ (2022-c). A Look At The New DC Charging System on My Vintage Sailboat, YouTube video retrieved online in May 2024 at this address.

SV Tritea (n.d.). Sailing Tritea, document retrieved online in May 2024 at this address.

Victron Energy (n.d.). Products, document retrieved online in May 2024 at this address.