T-Pain Is On A Boat: Re: [Electric Boats] Repowering 40' 1975 20,000 lb sailboat

Thursday, October 1, 2009

Re: [Electric Boats] Repowering 40' 1975 20,000 lb sailboat

I'll stick with fuel cells TYVM :)

But the TPPL's biggest advantage in this scenario is the greater charging range. Purportedly they can go to 30% DOD @ 1000 cycles. So that gives you %50 of usable AH energy in a "bulk-charge" scenario - compared to only %30 for a Concorde or similar AGM. So 200AH total gives you 100AH usable vs 60AH usable.

-Keith

--- In electricboats@yahoogroups.com, "dennis wolfe" <dwolfe@...> wrote:
>
> Keith,
>
> Concorde says their AGMs can be charged at up to 5C. You'd need a nuclear powerplant on board to do that!
>
> Denny
>
>
> ----- Original Message -----
> From: aweekdaysailor
> To: electricboats@yahoogroups.com
> Sent: Wednesday, September 30, 2009 6:52 PM
> Subject: Re: [Electric Boats] Repowering 40' 1975 20,000 lb sailboat
>
>
> I am finding that charge acceptance is an issue with my wet lead-acid though a quality AGM should be better.
>
> You ideally want to be able to put the full output of the generator into the batteries. With my setup it looks like I can only put 7-8amps in once the bulk phase is done. My genny/charger is ~22amp @48V and I could do 75amps if I had the juice.
>
> The TPPL (AGM) batteries Nigel Calder is pushing might be the best choice when extended cruising - with those you could put..say..30-40 amps in and reasonably expect to charge the batteries off the genset in 2-3 hours of running. Otherwise you'll be basically cruising with the genset running full time (or worse sleeping with it running) - some of the juice going into the batteries, but the rest you have to burn off by running the motor (or just waste)
>
> Otherwise, you'd have a fair chance of having to dock just so you could have quiet charging and a chance at sleep.
>
> I think lithium is ~price competitive with TPPL if you factor in dollars/lifetime-KWH -- that's *if* the 2000-3000 cycle claims hold up.
>
> My $0.02
>
> -Keith
>
> -----Denny Wrote---
>
> "Still hard to beat AGM lead acid batteries for a sail boat - especially if you
> can remove some of the lead you already have in the basement. A lithium bank
> will increase initial cost 5x and its benefits of light weight and rapid charge
> -discharge tolerance are not that important in your application."
>
>
>
>
>
> [Non-text portions of this message have been removed]
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