Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: Greenbeast on March 26, 2014, 11:49:20 AM



Title: End of Life UPS batteries
Post by: Greenbeast on March 26, 2014, 11:49:20 AM
At work we've just replaced the battery pack in an APC SmartUPS 3000.
I assume it decides they're end of life by age and not necessarily condition?

In which case, will they be worth me taking home? If i piut a meter on them, what voltage do i want to see for useful batteries?


Title: Re: End of Life UPS batteries
Post by: martin on March 26, 2014, 12:19:13 PM
Take them home, give them a charge (a car charger will do fine), then take the voltage after they've "rested" for an hour or two, anything over 12.7 volts you have life left in them! They're usually changed way before they're completely knackered


Title: Re: End of Life UPS batteries
Post by: Other-Power on March 26, 2014, 12:52:05 PM
Take them home, give them a charge (a car charger will do fine), then take the voltage after they've "rested" for an hour or two, anything over 12.7 volts you have life left in them! They're usually changed way before they're completely knackered

Dont use a car charger, SLA batteries have different charge characteristics to car batteries and they are sealed so any gas they produce cant be replaced. 

Chances are they will be degraded but to what point, the only way to know 100% is to discharge them to various sate of charge %, you can use something like this to work it out: http://www.ebay.co.uk/itm/Turnigy-130A-Watt-Meter-and-Power-Analyzer-in-stock-from-UK-with-fast-dispatch-/281106316902?pt=UK_ToysGames_RadioControlled_JN&hash=item41733dfe66 (http://www.ebay.co.uk/itm/Turnigy-130A-Watt-Meter-and-Power-Analyzer-in-stock-from-UK-with-fast-dispatch-/281106316902?pt=UK_ToysGames_RadioControlled_JN&hash=item41733dfe66)

Jon


Title: Re: End of Life UPS batteries
Post by: martin on March 26, 2014, 01:09:44 PM
OK lets be pedantic  -use a car charger if that's all you have, keep an eye on the voltage, and knock it on the head when it reaches 14.6 volts - if it's a typical 4 amp home car charger it shouldn't do too much harm as long as you're careful (I've used one to recharge gel "mobility" batteries used for electric fencing for ages without problems)


Title: Re: End of Life UPS batteries
Post by: Greenbeast on March 26, 2014, 01:55:13 PM
ok thanks guys