Originally Posted by chicodesouza
I'm new to the forum and want to give my congratulations to everyone!
Not long ago I bought my first sailboat (32 feet) and I'm redoing all the electrical
I'm trying to figure out the best way to make the management and control of load and consumption
of batteries, preventing loss and overcharging.
The whole electrical system
is 12V dc.
I have 4 power sources:
- Engine 29hp Yanmmar
- A solar panel
- A wind generator
- Source of land (equipment not yet installed)
I have 3 battery banks
- Lights and electronics
- Engine start (1 battery)
Could someone help me indicating what equipment should I buy to make this control and management and how to connect them?
Sorry about my poor english
. I hope you understood my question
Thank you in advance
It would be helpful to know what kind of consumption you have on board, and whether the solar and wind
more or less keep up with it or not. If you have light consumption which is mostly covered by solar and wind, then your system may be simpler, than if that is not the case. Do you have an inverter
In general, as has already been suggested, do by all means combine refrigerator and house banks.
1. Keep start and house banks as separate as possible. Echo charge the start batt from the house bank, probably. Do not use a "1, 2, both" type switch. Don't run anything from the engine start bank except engine starter (and engine electronics, if any). Larger boats often have separate alternators altogether for house and start -- probably overkill for your application.
2. Have a good MPPT
controller for your solar and wind.
3. Use a battery monitor
(NASA, Victron, etc.) to keep watch on your battery state and currents, but don't rely on the "% remaining" readout. Experienced sailors pay most attention to charging current
and voltage and mostly discount the calculated "% remaining" value.
4. Buy a good multistage battery charger
(Sterling, Mastervolt, Newmar, Victron, etc.) with charging capacity about 10% to maximum 15% of nominal battery capacity (that is, if you have 400 amp/hours of nominal battery capacity, you want a roughly 40 to 60 amp charger). If you're only using it with shore power
-- that is, no on-board generator -- then you don't need bigger charging capacity than that. If you need AC power on board, a combine inverter/charger is a good idea. This will give you the added function of controlling the amount of power you take from shore power
and boosting it with inverted power if needed.
5. If, however, your consumption is reasonably well covered by solar and wind, then it may be that you hardly need shore power charging.
6. Charging your start battery will require minimal power since you use a very small amount of the capacity of the battery every time you start the engine. So it's a great idea to install a separate, small, multistage shore power charger for the start battery. This helps keep everything as separate as possible between house and start banks.
7. Batteries should be matched to each other -- you're starting over with new, right? Choice of batteries is a whole separate topic outside of the scope
of this -- see the archives
for plenty of information. The very short version: don't use "leisure" type "semi deep discharge" batteries UNLESS you are on shore power nearly every night.
8. Don't let your batts -- whatever kind you have -- get below about 50% discharged. The deeper the discharge, the shorter their lives.
9. Very important: Use a good external regulator
for your alternator -- like Balmar
, Sterling, Adverc, etc. Without external regulation, car-type alternators do a poor job charging deep discharge battery banks.
10. Do a calculation of your consumption. If you're like most cruisers, refrigeration
will be by far the biggest consumer. It is often possible to save large amounts of power by properly insulating your refrigerator. You can dramatically reduce power consumption for lighting
by replacing incandescent with LED lights
-- highly recommended.
Good luck, and let us know how you get on!