OK I have been studying the literature list given me by Joel. I did
study all of this theory stuff back in the 1970s when I first got
into this stand-alone windpower stuff, but it was good to go over it
again, especially with my new enquiry.
I also have three fairly clear personal answers to
ge -
From: Hugh
To: RE-wrenches
Sent: Saturday, January 16, 2010 12:25 PM
Subject: Re: [RE-wrenches] discharging Rolls batteries
hi
We know that batteries deliver less amphours at low temperature and at
high currents. Volts drop quicker. That's my starting
e: [RE-wrenches] discharging Rolls batteries
> To: "RE-wrenches"
> Date: Saturday, January 16, 2010, 7:04 AM
>
> Re: [RE-wrenches] discharging Rolls
> batteries
> Hi Bruce,
>
>
> At 22:58 +1300 16/1/10, Bruce Geddes wrote:
> in cold
> weather
...@scoraigwind.co.uk>Hugh
To: <mailto:re-wrenches@lists.re-wrenches.org>RE-wrenches
Sent: Saturday, January 16, 2010 12:25 PM
Subject: Re: [RE-wrenches] discharging Rolls batteries
hi
We know that batteries deliver less amphours at low temperature and
at high currents. Volts drop quick
- Original Message -
From: Hugh
To: RE-wrenches
Sent: Friday, January 15, 2010 12:02 AM
Subject: Re: [RE-wrenches] discharging Rolls batteries
Hi Jamie,
Remember, as batteries cool actual capacity is reduced, so if 200AH is
50% @ 25C it is
http://www.battcon.com/PapersFinal2004/SymonsPaper2004.pdf
- Original Message -
From: Hugh
To: RE-wrenches
Sent: Friday, January 15, 2010 3:25 PM
Subject: Re: [RE-wrenches] discharging Rolls batteries
hi
We know that batteries deliver less amphours at low temperature
rate and you'll get the full amount.
Kent Osterberg
Blue Mountain Solar, Inc.
Hugh wrote:
Re: [RE-wrenches] discharging Rolls
batteries
hi
We know that batteries deliver less amphours at low temperature
and at high currents. Volts drop quicker. That's my
star
;mailto:re-wrenches@lists.re-wrenches.org>RE-wrenches
Sent: Friday, January 15, 2010 12:02 AM
Subject: Re: [RE-wrenches] discharging Rolls batteries
Hi Jamie,
Remember, as batteries cool actual capacity is reduced, so if 200AH
is 50% @ 25C it is significantly more than 50% @ 5C. Thus, you
Hugh,
I'll take a try at explaining what is going on with battery temperature
and high discharge rate issues. I hope Jamie will clarify, if I've got
it wrong.
A battery's capacity is the number of amphours that it will provide from
full charge down to a terminal voltage of 1.75 vpc. It isn
o: RE-wrenches
Sent: Friday, January 15, 2010 12:02 AM
Subject: Re: [RE-wrenches] discharging Rolls batteries
Hi Jamie,
Remember, as batteries cool actual capacity is reduced, so if 200AH is 50%
@ 25C it is significantly more than 50% @ 5C. Thus, you are discharging more
d
parameter, and
... the future. They say if I can come up with the algorhythm then maybe.
Thanks for raising this important issue, it is a problem almost every time.
Darryl
--- On Thu, 1/14/10, Hugh wrote:
> From: Hugh
> Subject: Re: [RE-wrenches] discharging Rolls batteries
>
Hi Hugh,
You are correct, my comments may have been too simplistic.
However, one other key point we are missing is discharge rate.
Note your comment, 400AH battery discharged at 10a for 16 (or 20) hours = 50%
DOD, which is probably not the case.
Use our S-530, which is 400AH @ the 20hr ra
Hi Jamie,
Remember, as batteries cool actual capacity is reduced, so if 200AH
is 50% @ 25C it is significantly more than 50% @ 5C. Thus, you are
discharging more deeply.
But earlier you put it this way:
Regarding temperature effects on capacity, earlier responses are
spot on as the lowe
Hi Hugh,
Based on your earlier number - regardless of temp effects - you were only
removing ~25% of capacity. You will need to lower your low voltage cut off to
improve performance.
Remember, as batteries cool actual capacity is reduced, so if 200AH is 50% @
25C it is significantly more
Hi Jamie and Dan,
Thanks for keeping up this thread! And sorry for being impatient.
Now, if the capacity 'loss' is simply due to reduced performance, is
it logical to say that one can push the battery to lower voltages
under low temperature conditions without actually cycling it harder
or re
Re: [RE-wrenches] discharging Rolls batteries
I wonder why there is no temperature compensation on low battery voltage
settings like there is on charging set points. Do I just have to use the
generator much more?
I may be wrong but my understanding of the Outback gear is that the temperature
ze easier.
Dan Brown
President
Foxfire Energy Corp.
Renewable Energy Systems
(802)-483-2564
www.Foxfire-Energy.com
NABCEP #092907-44
Original Message ----
Subject: Re: [RE-wrenches] discharging Rolls batteries
From: Hugh
Date: Wed, January 13, 2010 5:47 pm
To: RE-wrenches
#wm
Hugh,
Sorry if you found my response limited but have been traveling since early this
am and don't have all information at hand, at the moment.
Regarding temperature effects on capacity, earlier responses are spot on as the
lower capacity is totally as a result of slower reaction times as a
Thanks, Bruce,
I have lived with batteries for thirty years so I do know some of the
basic things but for most of that time I used secondhand batteries.
The last couple of years using expensive new ones I find that they
often perform less well. I would like to tap into the enormous
experienc
Corp.Renewable Energy Systems(802)-483-2564www.Foxfire-Energy.comNABCEP #092907-44
Original Message
Subject: Re: [RE-wrenches] discharging Rolls batteries
From: Hugh
Date: Wed, January 13, 2010 5:47 pm
To: RE-wrenches
Hi Jamie, Thanks for the very quick response! I note
Re: [RE-wrenches] discharging Rolls batteries
Capacity is reduced at low temperatures. Now does this mean that there
really is less energy in the battery, so that if I take out 50% of this reduced
capacity I will only end up with a 50% state of charge once it has warmed, or
is this just a
Hi Jamie,
Thanks for the very quick response!
I note that the temp compensation slope for charging is more like a
curve. It would be great to have a few more data points on this
curve to match it against the linear compensation programmed into a
Tristar controller.
But I guess there is som
un...@lists.re-wrenches.org] On Behalf Of James
Surrette
Sent: Wednesday, January 13, 2010 11:43 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] discharging Rolls batteries
Hi Hugh & Wrenches,
Regarding the charge voltages you sited, you've got the gist.
As battery temperature dr
: RE-wrenches
Subject: Re: [RE-wrenches] discharging Rolls batteries
Hi Hugh & Wrenches,
Regarding the charge voltages you sited, you've got the gist.
As battery temperature drops, you need to increase the charge voltage to
properly charge and, conversely, as temperatures rise,
Hi Hugh & Wrenches,
Regarding the charge voltages you sited, you've got the gist.
As battery temperature drops, you need to increase the charge voltage to
properly charge and, conversely, as temperatures rise, voltage needs to be
decreased to reduce the risk of overcharging.
I believe the
Hi wrenches,
I have been selling and using a few sets of Rolls 4000 series S530
batteries lately.
I have downloaded the Solar Battery manual from www.rollsbattery.com
It's very interesting. At 17 degrees C you need to charge at 14.4
volts. At 16 degrees it's 15 volts. Hmm, Ok I get the id
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