T-Pain Is On A Boat: Re: [Electric Boats] Charging batteries in series?

Friday, January 30, 2015

Re: [Electric Boats] Charging batteries in series?

Myles,

The point I was making was the BMS system you need that is not needed with
NiFe. One system failure can cost you big time with LiPo. If we are going to
go trouble free in a harsh enviroment there is no better than NiFe chemistry.

The thread is more about saving your batteries the way I see it. If that is
the case and you are going to spend on batteries one should at least look into
NiFe and remember high tech fails more often than we want to admit.

Kevin Pemberton

On Wednesday, January 28, 2015 10:14:45 PM you wrote:
> Regarding NiFe batteries, Jeff indicated:
>
>
> "Wow, this *is* interesting. I'm looking at the spec sheet for the 300Ah
> cell at 1.2v. So for 48v I would need 40 of them, and at 23.1 lbs per cell,
> that is close to 900lbs of battery :) Using their pricing page it looks
> like that pack would cost $11,400. Has anyone used these for EV
> applications yet? I do love the idea that you can abuse the crap out of
> them. They claim 11,000 cycles."
>
>
>
>
>
> Jeff- Such a pack would yield just shy of 15kwh and cost almost 1.5x what my
> 30kwh of ex-THINK EnerDel lithium modules cost (3x kwh/$). My pack weighs
> about 650# (3x kwh/#). If you have $11k for batteries, there are lots of
> options available to you.
>
>
>
>
>
> As for cycle life, for pleasure boat use, more than a thousand cycles seems
> like a multi-lifetime concern and value. I mean, how many of us charge our
> packs more than 3x per month on average? I'd guess that with PbA, I was at
> about 30 charge cycle per year usage. Now with a larger lithium pack, I
> probably am looking at 15-20 charge cycles per year. My pack is likely good
> to 2000 cycles with still 80% capacity after that---i.e. these lithium
> batteries' won't be seeing that cycle life for the next 100 years and will
> more likely die from some other fate before then.
>
>
> I couldn't place a value on 11,000 cycles for a pleasure boat battery pack
> unless it were also my commute boat or I otherwise got it out every day of
> the year for 35 years and had to recharge it daily.
>
>
>
>
>
> -Myles