[Boatanchors] GEL CELLS

[D C _Mac_ Macdonald]

Not to strain at gnats, Brian, but didn't I state that gel cell charge voltage should be between 13.5 and 13.8 for a maximum ? ? ?
 
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* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk hotmail com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
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> From: brianclarke01 at optusnet.com.au
> To: k2gkk at hotmail.com; w4byg at att.net; boatanchors at mailman.qth.net
> Subject: Re: [Boatanchors] GEL CELLS
> Date: Thu, 22 Jan 2015 14:32:18 +1100
> 
> Not that simple.
> 
> The gassing Voltage depends on the temperature, too.
> 
> Car battery charging systems often charge up to 14V5, in spite of the 
> under-bonnet temperature. Why is it set so high? A couple of reasons - the 
> battery can be fully charged, and first thing in the morning, when air 
> temperature is usually low, the car's engine will start. This temperature 
> cycling and operating at beyond gassing temperature are some of the reasons 
> that car battery manufacturers only offer a one-year guarantee on car 
> batteries. Where it is possible to alter the set point, I set it at 13V65 
> which is below gassing Voltage for most operating temperatures.
> 
> Sealed lead-acid batteries (SLABs) and gell cells have even less room to 
> manoeuvre than flooded cells (those in car batteries). With SLABs, there is 
> only limited volume available for gas production. With gell cells, once the 
> acid in the gell gasses out, there is no simple way to replace the lost 
> water.
> 
> Another little point: many self-styled pundits - even among the ARRL 
> editorial staff - warn of the dangers of charging batteries in confined 
> spaces  "because they give off hydrogen which is explosive". Hmmm. Simple 
> analysis of the chemistry of lead-acid cells' charging and discharging shows 
> that the gasses given off are hydrogen and oxygen, in exactly the correct 
> ratio to recombine explosively if there is a naked flame around, eg, welding 
> in a motor mechanic's garage while charging batteries. Warm, concentrated 
> sulphuric acid does wonders to your favourite radio equipment, your car and 
> your bank balance.
> 
> 73 de Brian, VK2GCE.
> 
> 
> On Thursday, January 22, 2015 1:50 PM , Mac said:
> 
> "Float" a quality "12V" Gel Cell battery at 13.5 to 13.8 volts (2.25 - 2.30 
> volts per cell) and it will last a minimum of 5 years.
> 
> Applying more than that 13.8 for much time will severely shorten its life!
> 
> Straight from Powersonic's user guide!
> 
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> * 73 - Mac, K2GKK/5 *
>