What voltage to charge a Numax CXV battery?

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nlong

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I am changing my old open lead acid batteries to a new sealed ones. I have purcahsed two Numax CXV24MF which I think are based on calcium lead plates. I have read that these need a higher charging voltage than the old open battries.

The setting on my charger offer a "lead sealed" setting of boost/absorbtion setting of 14.3V then floating at 13.6V or a higher setting for "Calcium Lead Tin" of boost/ absorbtion at 15.1V followied by a floating voltage of 14.4V.

Anyone know which is best for this type of battery?

Many thanks
 
I dont think they are " calcium" batteries.

Dual purpose ( ie leisure/ cranking), dual terminal ( so that you can connect your solar panel easily) and sealed " maintenance free" but I see no mention of calcium in any descriptions or specifications.
 
It apparently is silver-calcium see http://www.advancedbatterysupplies....leisurebattery.html#leisurebatteryinformation
However although they describe it as "sealed lead acid" it has a "magic eye" state of charge indicator. To me that makes it a wet battery - a "sealed maintenance free" rather than true "sealed lead acid". Misleading.
IMHO the calcium setting on your charger is much too high (is it a Cristec? Mine has similar silly numbers.) and will cause water loss. I would stick with the 14.3/13.6.
Do Numax not give any guidance?
You should go by what they say not by what the charger manufacturer says.

This http://www.manbat.co.uk/cm/files/brochures/battery_specification.pdf appears to be the manufacturer's catalogue but no guidance unfortunately. Why not email and ask them.
 
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VicS said:
I dont think they are " calcium" batteries.

Dual purpose ( ie leisure/ cranking), dual terminal ( so that you can connect your solar panel easily) and sealed " maintenance free" but I see no mention of calcium in any descriptions or specifications.
Click to expand...

Virtually all "sealed" or "maintenance free" batteries use a calcium-lead alloy for the plates. This reduces gassing, reduces self-discharge and, conveniently, allows a faster manufacturing process.

I've seen a spec here which suggests this Numax battery uses a calcium-silver alloy of lead.

For charging, I'd use the "sealed lead" setting.
 
pvb said:
Virtually all "sealed" or "maintenance free" batteries use a calcium-lead alloy for the plates. This reduces gassing, reduces self-discharge and, conveniently, allows a faster manufacturing process.

I've seen a spec here which suggests this Numax battery uses a calcium-silver alloy of lead.

For charging, I'd use the "sealed lead" setting.
Click to expand...

Can I claim a Lakesailor? :)

Actually lots of sealed maintenance free batteries (not sealed lead acid) are low antimony not calcium. Lead antimony is easier to cast than lead calcium (That was our manufacturing experience anyway. I don't know if silver improves the castability, that is a more recent introduction.)
 
Thanks for the reply, yes it is a Cristec charger, so will probaly stick with the sealed lead setting.

I have sent an email to the manufacturer Manbat but no reply yet.
 
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