"Tom Biasi" <tombiasi***@[EMAIL PROTECTED]
> wrote in
news:SN6dnboY57y6pf3VnZ2dnUVZ_gCdnZ2d@[EMAIL PROTECTED]
>
> "Kris Krieger" <me@[EMAIL PROTECTED]
> wrote in message
> news:X9udnZAE58lEr_3VnZ2dnUVZ_jmdnZ2d@[EMAIL PROTECTED]
>> "Tom Biasi" <tombiasi***@[EMAIL PROTECTED]
> wrote in
>> news:CrydnV3Ospmxm_3VnZ2dnUVZ_vninZ2d@[EMAIL PROTECTED]
>>
>>>
>>> "Kris Krieger" <me@[EMAIL PROTECTED]
> wrote in message
>>> news:HN6dnUa5Bpt2esLVnZ2dnUVZ_h3inZ2d@[EMAIL PROTECTED]
>>>> Apologies in advance if this is a dopey question, but, when it
>>>> comes to recharging batteries, and using a solar cell to do that,
>>>> what I've been assuming, based on th info that peopl ehere have
>>>> kindly provided, and also that I've foind on-line, is that teh mA
>>>> output of the solar cells should not exceed 2/10ths to maybe
>>>> 3/10ths of the battery's mA rating, and teh voltage produced by the
>>>> solar cells should be as close as possible to the total voltage of
>>>> the battery or batteries. But I wanted to check whether that
>>>> assumption is correct, becasue I think I'm getting closeto getting
>>>> some parts and trying a couple of assemblies.
>>>>
>>>> Thanks In Advance!
>>>>
>>>> - Kris
>>>
>>> Hi Kris,
>>> Different batteries need different charging conditions.
>>> Look at the specs for your batteries.
>>> The charging requirements will be discussed.
>>> Some batteries may say: Charge at .1c for 10 Hrs.
>>> This means to charge them at one tenth the AH rating for 10 Hours.
>>> The VPC (volts per cell ) will also be specified.
>>> For example: NiCads are about 1.2 VPC and can charge at about
>>> 1.3-1.5 VPC (follow manufacturers specs) at .1 -.3 c. (again, follow
>>> specs.).
>>
>> Ah, OK, that at least gives me a ballpark figure - thanks :) !
>>
>> (I do try looking all these things up via Google before posting
>> questions, but often, I don't know the terms that will get me the
>> correct *type* of answer - IOW, if I want info about charging, I
>> don't want to look at endless lists of people selling battery
>> chargers, but the latter is the sort ofthing I've been having to
>> trudge through...so even just getting the right terminology has been
>> a huge help).
>>
>>> So if you have a 12 volts NiCad pack that would be a 10 cell NiCad
>>> battery. If you are using lead acid cells, the numbers are
>>> different. Keep in mind that photo cell manufactures inflate their
>>> specs by using bright sunlight averages.
>>>
>>> Tom
>>>
>>
>>
>> THe Max I'll use will be 4 1.2V NiMH batteries, for small lighting
>> units. What I'm trying to figure out is how to avoid "cooking" the
>> batteries ;) by putting in *too much* voltage, but I also want to
>> take into account the very thing that you mentioned, i.e. the
>> "brightest possible sunlight" rating for the cells.
>>
>> I had bought some Malibu NiMH batteries at WalMart, but now i'm
>> looking at ordering something more along the lines of Energizers (for
>> example,
>> http://www.rei.com/product/719570?cm_mmc=cse_froogle-_-datafeed-_-
>> product-_-na&mr:trackingCode=B42A264C-BE3F-DD11-98CA-001422107090
>> &mr:referralID=NA or these
>> http://www.circuitcity.com/ssm/Duracell-AA-Rechargeable-Batteries-4-Pa
>> ck- DC1500B4/sem/rpsm/oid/52666/catOid/0/rpem/ccd/productDetail.do)
>> or one of the other known/name brands, because just today I read some
>> cautions regarding "bargain" batteries.
>>
>> I at least found some interesting LEDs at
>> http://www.optekinc.com/viewparts.aspx?categoryID=53
, some of them
>> claim to put out 18,000umc average using 20mA and typical "forward"
>> voltage of 3.4, so that I can run off of a reasonable LED driver
>> (considering some Maxim items, or the "Micro-Puck").
>>
>>
>> ANyway, I'll look around and see whether ther eis info about
>> recharging. THis is good to know because, assuming I can do what i'm
>> intending, and call sell the units, I can also incoude costomer info
>> as to the best replacement batteries, should replacements be
>> necessary.
>>
>> Thanks again :)
>>
>> - Kris
>>
>>
>
> When you search you may try something like "solar battery charging
> tutorial" When you add 'tutorial' you will get better hits on your
> search. BTW: NiMH have very fussy charging characteristics.
Thanks!, I'll try that.
>
> May I suggest deep cycle sealed lead acid.
>
> Tom
>
My main question is, are they easily replaceable? THey do seem to be
easier to deal with, but these units are going into things that I'll
(hopefully!) be selling, so I need to make it all as easy as possible, and
I know that people can buy the NiMH batteries pretty easily. That's the
only reason I've sort-of "fixated" on them. THat, and it's easy to get
the
mA ratings that will drive the LEDs I want to use (found one that uses 20
mA, and 3.4V average, but gives out an amazing (to me) average of
18,000micro-candela, which is 226 lumens, which is a bit more than is
given
off by a 20-watt incandescent bulb (220 lumens). With the LED driver (I
think it was you who'd recommended those), that should work out well and I
could, I think, use two such LEDs, which should be about the lumens
produced bya 40 watt incandescent bulb - which would be super!
Anyway, I haven't seen any drivers that I can recall reference running off
of anything other than NiCad, NiMH, or Lithium-Ion batteries,so my
impression was that those are the only two that have both enough voltage,
and generate enough current, to run the drivers. I've also used store-
bought solar lights, which had either NiCad or NiMH (depending upon th
etype), so I know those will work when left outdoors.
So, it might very well be that rechargeable lead-acid bnatteries can
perform similarly, it's just that I don't know anything about them...
- Kris
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