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Monday, 27 February 2012

The cost of power

The one thing that everyone wants on boats is free electric, well unless you have an 'eco' powered boat with solar panels and wind generators adorning every inch of the boats surface and moor in an open space to catch the sun and wind then I am afraid that there is nothing you can do except to generate it yourself using the tried and tested methods of a well maintained battery bank, and have a good method of charging said batteries, a good quality inverter to convert that power to 240 volts and if you can afford it a built in diesel generator which will either aid the charging of the batteries and also supply you with a decent amount of 240 volts, of course all this is less important if you are permanently plugged in to a shore line and rarely move your boat, but to do it properly costs money.

I lived on many boats since my first boat back in the late 80's, that was of course very basic and all I could afford was one battery and a Halfords type battery charger, if I was away cruising I relied totally upon the engines alternator to charge the battery and that was fine, when I Started living aboard I needed more batteries to cope with the extra demand that I placed upon the supply, eventually as my needs changed so did my boats and subsequently so did my power requirements, the last boat that I lived on had 6 domestic batteries, twin alternators, a battery management system, a battery management monitor(like a battery level gauge) a big inverter and last but least a decent built in diesel generator, I also had a smaller portable generator as a back up if everything else failed, needless to say that the whole system was costly but while I was away from shore power I enjoyed effortless power supply, I checked my batteries monthly for electrolyte levels, topped them up as required, I kept the battery terminals free from 'canker' kept the tops of the batteries very clean, all kept in a well ventilated area and most importantly I never ever let the batteries discharge below 12 volts, The batteries lasted for about five years and when the performance dropped to a level that I wasn’t happy with that is when I changed them for a new set.

My boating has changed massively since them days and now I only boat for pleasure but I still have the same disciplines as when I lived on a boat with regards to the batteries, just before I laid my boat up for the winter I carried out the usual checks on the batteries, levels etc and cleaned them and left them on my smart four step charger over the winter, upon visiting the boat recently they are all in excellent condition and ready for another seasons use.

we sell hundreds and hundreds of batteries a year, when we do a full engine service we include a battery check as part of that service as we believe it is an important commodity, If you look after your batteries then they will look after you and you should get a reasonable life span out of them, abuse them and be prepared to be let down by them when you least expect!

Its been a wet horrid today at Norbury, nothing exciting has happened, no boats have been seen moving so noting really to report about so until tomorrow.

1 comment:

  1. I have just read the article on "Cost of Power"
    Everything is spot on - however, I cannot admit to being so thorough. My batteries often fall to 22-vdc and occasionally have dropped to 20-vdc (Opps!)

    I have a 24-vdc installation so a 12-vdc comparison would be 11-volts dc and 10-volts dc)

    Fortunately my inverter cuts out at 22vdc so saves absolute discharge potential. (Programmable)

    I live on board, so never let the batteries remain for very long without a FULL recharge. This sometimes takes as long as 6-hours running of the engine to achieve this!

    I too, have a battery state monitor. It doesn't seem to be at all accurate. The 0% to 100% reading varies and doesn't agree with the "State of charge" as shown by my inverter LEDs

    I have "halved" the voltages, as I have a 24-vdc system. I did this to give a reasonable comparison for other readers

    Until recently, I had 4 x 12-v x 130-rated Solar panels. These panels (Over a 12-month period) reduced my diesel costs by about £20.00pw. This gave me a capitol outlay return (Paid for) in just over 2 years - I consider this a worthwhile investment. (My panels have been destroyed by storm/winds recently) - They took off from the roof and ended up on the towpath!

    This is a blessing in disguise. The insurance covered the damage and sent me a cheque within 21 days - VERY satisfied, excellent service! (My Brokers are "Nautical" and I personally highly recommend them)

    I was able to purchase replacement panels for the "Pay-Out" cheque and they are 4 x 24v x 190-watt rated. This is virtually a threefold increase in stated watt output and should improve my diesel fuel costs (Less fuel) They are yet to be fitted

    For fantastic technical advice, contact Marlec at Corby. THey manufacture the Rutland and stock high quality "Schott" (German) Solar Panels

    Fortunately I installed the latest digital panel controller (The American Tri-Star)- also ex. Marlec.

    It is a lovely instrument and records data for at least a month! This enables me to have any input voltage up to 150-volts and set the output to suit my 24-vdc system.

    The Tri-Star is OK for: 12v, 24v or 48v battery banks. It monitors the batteries (Including temperature) the input charge available and balancing the input/output to give best possible charge (Virtually no losses) in real time. This is supposed to be a substantial improvement over the resistance/shunt type of controller. I am looking forward to looking at my new records (When the new PVs are fitted) against my old records. I am hoping to see less usage of diesel to recharge my batteries.

    Unless actually cruising, I would estimate that the new panels should produce more charge than my electrical requirements in the "good" weather and avoid running the engine,(Hopefully),several days in each week, something I have never been able to achieve whilst being on the boat
    (I would never expect it to cope with the washing machine though!)

    I hope other boaters find my comments interesting and perhaps of some use if they are considering fitting Solar Panels, or wind generator

    I nearly forgot, I have the latest Rutland 914i digital wind generator. The payback time, I would estimate, will be around 4 to 5 years on the outlay. My Solar Panels had an approximate payback time of only 2.3 years, so Solar Panels wins my vote every time for producing more over the year, per UK pound outlay

    A wind gene is a luxury and is useful during Dec through Feb but don't expect too much from this type of "free" generation of power

    Regards, ~Allan~