Author Topic: Is there such a process, of recharging batteries to fast?  (Read 1422 times)

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kbhale

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Is there such a process, of recharging batteries to fast?
« on: December 17, 2009, 11:50:18 PM »
Is there such a process, of recharging batteries to fast?  I have a 12 volt battery bank, 690 amphours and plan to add a lot of solar panels. In the next few months hopefully.
« Last Edit: December 17, 2009, 11:50:18 PM by (unknown) »

wpowokal

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Re: Is there such a process,
« Reply #1 on: December 18, 2009, 12:14:29 AM »
Yes, one of many sites for such information.

http://www.bigginhill.co.uk/batteries.htm


there are many criteria, read this, Google on your make of batteries then ask any unanswered questions.


Of course a charge regulator takes care of it for you but does not empower you with the knowledge.


allan

« Last Edit: December 18, 2009, 12:14:29 AM by wpowokal »
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Flux

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Re: Is there such a process,
« Reply #2 on: December 18, 2009, 12:33:53 AM »
Every battery has a maximum acceptable charging current, it is high for low states of charge but falls as the thing charges.


You should keep below the maximum for your battery to not risk damaging it. As Wpowokal said a charge controller will take care of the battery as long as you don't exceed the maximum during the bulk charge phase but you may be dumping most of your produced current later in the charge cycle if the battery is too small.


If a battery is too large you may never keep it fully charged and shorten its life. If it is much too small you may exceed the maximum permissible bulk charge rate ( unless you have a current limited controller and solar ones normally aren't).


If you can plan things such that you are drawing off the excess current to loads then it is not an issue but most charge management doesn't cater for these factors.


Flux

« Last Edit: December 18, 2009, 12:33:53 AM by Flux »

ghurd

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Re: recharging batteries to fast?
« Reply #3 on: December 18, 2009, 07:34:34 AM »
If the charging current is anywhere near the max allowable charging current,

you have too many panels, or not enough batteries!


The power must be stored to be used at night.

Just because the panels can make the power does not mean the battery can store it.


C/10 (69A of solar current, 1000 or 1200W at 12V) will jump the voltage up to regulation in a very short time (measured in minutes instead of hours).  The controller starts controlling, which is when much of the money spent on panels is being wasted.


C/20 is generally plenty to get the battery (unloaded) up to regulation in a reasonable length of time.

Depending on how and when you use the battery, 500 or 600W would be a decent match.

With that much panel, something like an MX60 or FX80 would be definitely worth the investment.


If the battery power is mostly being used when the sun is up, say a 9-5 home office or something, more panels could be a good idea.

G-

« Last Edit: December 18, 2009, 07:34:34 AM by ghurd »
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