Congrats it sounds like a fun race. Thanks for the info, so if you stayed in the 80% range on a lithium you should be able to do well.
Thanks
Nick
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Ned Farinholt
Sent: November-23-11 9:58 AM
To: electricboats@yahoogroups.com
Subject: Re: [Electric Boats] Battery Life
Nick,
Yes, LA batteries last longer if cycled at less than 50 to 80% of their rated AH, assuming they are deep discharge batteries. Less if not deep discharge. Lithium do not have a memory issue. Lithium vendors, e.g. Thundersky claim 2000 + cycles. However, with LiFePO4's you are better off with a battery management system which will let you know when you are reaching the max discharge point. Going beyond this will shorten the life according to the manufacturers. Also the Li discharge curve is very flat. You can get about 90% of the stored charge. You may have seen this in the non-rechargeable Li AA batteries: work great until the end and then die abruptly. I have only had my 52v 160 AH bank for one season. The great value to me was the high energy storage per pound. It allowed me to win the Wye Island Electric Boat Marathon: 24 miles at 10 mph. See: http://www.proptalk.com/proptalk-magazine pp. 34-36.
Have a blessed Thanksgiving,
Ned
On Nov 22, 2011, at 11:15 AM, Nick Boersema wrote:
Battery Life
If I understand correctly with a lead acid battery the smaller the range you cycle it in the longer it will last. First question is that correct. Next question is there a similar situation with lithium? I know my old nicads had to be drained completely from time to time or they developed memory and lost volume is there a similar situation with lithium? How long is the average battery bank life in a boat application? Is it too early to know? Lithium users how old are your battery banks?
Thanks
Nick
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Mike
Sent: November-22-11 7:26 AM
To: electricboats@yahoogroups.com
Subject: Re: [Electric Boats] Re: new lithium battery breakthrough?
Don:
I was referencing my Honda Fit car. Which is different from my Honda 2000eu generator that I use on the boat. Both IMO are very reliable. The car "fits" my needs perfectly. In four years I've managed to only put 16,000 miles on it. No, It's not electric sorry if I gave that impression. Though my lifestyle and driving needs is perfectly suited for an electric car if one was available and was was not crazily overpriced. It's also one of the reasons why I did not buy a Prius as it was not suitable for my driving needs. My point was the three year old car battery has already needed to be replaced while my boat's 48 volt AGM bank shows no signs of failing after four years. Yes, the boat bank does not get jared as much as the car so that's part of it. It's also a deep cycle compared to the cars starting type. I also keep a closer eye on it and use solar and wind (though my wind generator was not installed this year) along with an occassional AC charge to keep things topped up and in balance. Not sure how well a Tesla car batteries hold up. But, I know of one Prius owner that needed her battery pack replaced under warrenty. Not sure why though. I think we are all still trying to see how long a battery bank (flooded, AGM, Lithium) will last in some of our electric boats. I can't speak for others but, so far so good on my boat for four years so far.
Capt. Mike
From: Don Parsons <tdparsons@msn.com>
To: electricboats@yahoogroups.com
Sent: Tuesday, November 22, 2011 12:42 AM
Subject: [Electric Boats] Re: new lithium battery breakthrough?
Hi Mike,
I value your veiw.
Your blog is an inspiration to us all on this forum.
I re visited your blog to look for a reference to a 97 Honda
but I have to assume it is a car not a generator that you are refering
to. Now is it an electric car battery pack? Or just the starting battery you mentioned. I wonder how long the Tesla battery packs have lasted.There should be some info by now. They have been around for awhile.
Boats would seem to jar the pack less, is that your drift?
If so , just another plus for applying elec to boats. Of course the other obvious is cruise/elec. boating usually means going someplace and then sitting there for awhile, perfect for charging via solar, wind, shore power, etc. Really does seem to be a better(easier)fit than cars.
Don
--- In electricboats@yahoogroups.com, Mike <biankablog@...> wrote:
>
> Don:
> Â
> Well, I've just finished my fourth season with EP and so far the pack has been holding up very nicely. I was just on the boat yesterday and fired up the Dual Pro charger and the batteries came up to charge with in thirty seconds or so of each other. I've probably only taken them down 30% at most on my trips so I'm hoping to get a lot of charge cycles out of them at that rate. I'm not sure but, I figure I might have charged them perhaps 50 times tops using the chargers over the past four years.  My 1997 Honda on the other hand has already had to have it's battery replaced last year. Though it is of course of a different plate construction and gets bounced around a bit more. Part of me thinks maybe I should use these batteries at home in the winter as part of my continuing solar conversion of my house. But, the idea of lugging 800 pounds of AGM batteries around with the real chance of dropping and damaging them prevents me from actually doing it.
> Â
> Capt.Mike
> http://biankablog.blogspot.com
>
>
> ________________________________
> From: Don Parsons <tdparsons@...>
> To: electricboats@yahoogroups.com
> Sent: Monday, November 21, 2011 10:28 AM
> Subject: [Electric Boats] Re: new lithium battery breakthrough?
>
>
> Â
> That was an interesting link Ben,
> Well worth veiwing.
> Thanks , now I am late for work.
>
> As far as the lump sum of replacing batteries is concerned.
> I am not sure it is really a big problem.
> Has anyone noticed that after 8-10 years the value of your
> car or truck is valued as almost nothing when you go to trade it in?
> If someone wanted to buy your old electric car it really would not be
> cost prohibitive to get a 8-10 year old electric car cheap and put a new battery pack in it would it?, of course assuming the pack lasts
> 8-10 years.
> Don
>
> --- In electricboats@yahoogroups.com, Ben Okopnik <ben@> wrote:
> >
> > On Mon, Nov 21, 2011 at 02:19:34PM +1100, Andrew Gilchrist wrote:
> > >
> > > Regardless batteries are not popular in cars because they confront owners with
> > > high lump sum replacement cost
> > >
> > > That may never be resolved.
> >
> > Been resolved already. :)
> >
> > www.ted.com/talks/shai_agassi_on_electric_cars.html
> >
> > I love TED-talks anyway, but this guy is one of the most electrifying
> > (no pun intended... OK, then, *don't* believe me :) speaker I've seen
> > there. Listening to his talk is like drinking a good bottle of wine.
> >
> > Incidentally, the system is already in place in Israel, Sweden (IIRC),
> > and Japan. *Awesome*, brilliant bit of social engineering that deals
> > with exactly the problem cited above.
> >
> >
> > --
> > Ben Okopnik
> > -=-=-=-=-=-
> >
>
No comments:
Post a Comment