Batteries and Electrical systems
One of the challenges cruising, especially when not in a Marina is that we are the utility department. We are the power company, the water company and the waste water company. We have to provide it all.
Even more important is that these are mission critical. If the water is not working, the toilets don’t flush, nothing gets washed and the crew gets very cranky. Obviously waste water must be taken care and while we used to use a bucket for the toilet on our first racing sailboat a Santana 20. That won’t fly anymore.
Everything on the boat relies on electricity. From starting the engines to keeping our margarita ice and fish frozen. No electricity no cruising.
If you aren’t interested in geeking out about electricity…. Stop reading now.
On Elizabeth Anne, we’ve got a lot of redundancy for sources of electricity.
- 12kw Generator
- 8kw Generator
- Two separate 140amp alternators, one on each main engine. 3.7kw each.
- 700 watts of solar panels
We’ve done lot of customizing of the electrical system and I’ve now got a good understanding of the system. I recently got an email from Bruce Williams on “Odyssey” and we were discussing battery banks and typical electrical loads for cruising boats.
Bruce said “Next thing I need to work on is to reduce the load on the batteries. When at anchor I pull about 60 amps at 12 v.
I keep my navigation, auto pilot, etc. electronics on so I can see if my anchor slips. I think I will turn all that off and
just use my Ipad app for that.
How much do you pull when at anchor ?”
Since many of you who read this blog are cruisers I thought I’d create a post with a little discussion. Bruce asked me what our electrical load was overnight while at anchor. We were looking at how long we could stay at anchor and not run a generator.
Bruce’s load is about 720 watts. Which is a lot. It is likely refrigeration running at that load.
I’ve got a Victron battery monitoring, inverter /charger system. The color CCGX monitor also logs data and uploads to Victrons server. The graphs that follow are for the time from 12:40am to 7:00am.
Here are three graphs from this morning. We’re on a mooring ball at Wardrick Wells now. I charged batteries last night to 97%. First graph is AC loads.
120 watts is my AC base load for all of the parasitic loads. DirecTV box is a big part of that along with the TVs apple chargers, printer and electronics built into all of the appliances.
I’m glad I don’t own a boat any more! I’ll just hitch a ride with you guys!
You’re always welcome aboard
John,
We use a battery monitor that registers amp hours out and then charging back in. We have a 580 amp hour bank and will typically see 100 amp hour drop overnight running our Frig, freezer, tv. and computers. We have an 8kw generator and 650 watts of solar. I can’t imagine running complex systems that you have on your vessel. I would think you have to have a big battery bank.
Bill Creadon
SV Georgia Song
Bill,
Elizabeth occasionally feels complex, but really it is just more of the same stuff mechanical electrical stuff you’ve got, without the hassle and expense of sails and rigging.
We’ve got 700 watts of solar panels and our bank is 540 amp hours at 24V, but since it is Lithium we use about 80% of the battery capacity most of the time.
Hi John, great post and a subject near and dear to my heart right now. As you know my wife Lindsey and I recently purchased the former M/V Copeing from Ray and Susan. Great boat and we love her and now have the challenge to keep her up to Ray’s benchmark. As we speak I’m battling a ~15yr old Xantrex inverter that doesn’t seem to want to go to charge but works fine on the inverter side. Fortunately the ~1.5kW solar is keeping the bank happy. On your lithium system is it an integrated inverter charger or separate devices? Interested in how long ago you went to Li and your opinion now. If there is a better post to refer me to fell free. thanks