Commissioning of New Battery Banks
Commissioning of New Battery Banks
(OP)
Is Discharging test required for the commissioning of Battery Bank for UPS.What are the test required before commissioning & during commisssioning of New Batteries,
thanks in advance
thanks in advance






RE: Commissioning of New Battery Banks
At a miniumum, the battery internal resistance is measured (Alber Cellcorder) to establish the reference for later measurements during the life of the batteries..
We do quarterly load tests at several joint commission certified hospitals here in the USA. It's specificly called for and specifies the type of load test to be done. http://www.jointcommission.org/
RE: Commissioning of New Battery Banks
RE: Commissioning of New Battery Banks
For all the UPS jobs we did in last 12 years (including at my past employers) , we had battery discharge test as mandatory requirement. To me that is the only reasonable way of knowing if the batteries are good, at least for a while. In fact, we as consultant would insist on it and no one ever has resisted.
I have seen a whole set of batteries (a few years old) last a total of 0.5 sec after all the passive tests were being passed on as good or acceptable!
Check out IEEE 450 for wet cells and IEEE 1188 for dry. While there is no "law" requiring it, it is a matter of prudence.
Rafiq Bulsara
http://www.srengineersct.com
RE: Commissioning of New Battery Banks
"Theory is when you know all and nothing works. Practice is when all works and nobody knows why. In this case we have put together theory and practice: nothing works... and nobody knows why! (Albert Einstein)
RE: Commissioning of New Battery Banks
RE: Commissioning of New Battery Banks
RE: Commissioning of New Battery Banks
To clarify: We did not do the DC load bank test, which mostly is useless as it does not test the final system and connections.
Our discharge tests are on a load bank connected to UPS output and kill the ups input power to see the load is served via the UPS inverters on battery for the designed duration. Thus the actual system is tested with final connections.
Rafiq Bulsara
http://www.srengineersct.com
RE: Commissioning of New Battery Banks
you mean to say that the Load needs to be connected with UPS output.Normally we connect the Resistive load to Battery banks whihc are charged & discharge the battery through them.While keeping a constant load , the rate of reduction of voltage with time is monitored.
RE: Commissioning of New Battery Banks
Rafiq Bulsara
http://www.srengineersct.com
RE: Commissioning of New Battery Banks
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RE: Commissioning of New Battery Banks
It reminded my of a standby generator installation I did in Central America. The gen-set worked fine and everything tested good. I was due to leave for Canada in a few days. All testing had been done with the test switches on the Automatic Transfer Switch. On the way out the last time, I decided to give the set one last test by opening the main incoming breaker instead of using the test switch. NOTHING. It turned out that there was a relay that was Not in the circuit when the test switch was used but was used during a utility failure and the relay was defective. Had it not been for the final breaker test, I would have been back in Canada when the next power failure hit and the generator failed to start.
I heartily support your total system testing method.
Yours
Bill
Bill
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"Why not the best?"
Jimmy Carter
RE: Commissioning of New Battery Banks
RE: Commissioning of New Battery Banks
In a UPS this is done by controlling the DC voltage of the rectifier, for systems that have the batteried directly connected to the DC bus.
Many newer UPSs don't directly connect the batteries. In this case there will be a seperate charger for the batteries. Again the maximum current will be limited to 10% of the C10 rating.
Basically there is two stages to the charging cycle.
1. Constant current. The current is limited to the maximum charging rate by adjusting the voltage to the battery. Depending upon the depth of discharge this can last up to an few hours or so.
2. Constant voltage. At the end of the constant current cycle the voltage across the battery has reached the nominal charging voltage. Current will still flow for about 24 hours with the voltage kept at the float level. At the end of this period the battery will then stay in trickle current mode.
Charging a VRLA battery at higher currents will result in 'gassing' of the battery which will shorten the operational life of the system.
RE: Commissioning of New Battery Banks
RE: Commissioning of New Battery Banks
Rafiq Bulsara
http://www.srengineersct.com
RE: Commissioning of New Battery Banks
The majority of battery manufacturer's require a full battery discharge test in the UK to be completed before any warranty claims can be made.
And yes we do do cellcorder or midtronics testing in the UK but it does not replace a discharge for warranty claims.
UPS engineer http://www.powerups.co.uk
RE: Commissioning of New Battery Banks
Phew, that's brave! A few of the battery manufacturers might have something to say about that, especially if they are covering the cells under warranty.
See Section 2.6 for Hoppecke's recommendations: no limit on current below 2.4V / cell, then roughly C/10 to C/20 depending on the type. The figures are fairly typical for flooded lead-acid cells.
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If we learn from our mistakes I'm getting a great education!
RE: Commissioning of New Battery Banks
I have always thought this was dubious as there are obviously mechanical connections that have to carry the current. But I was only passing on what I have been told by people who work at the battery companies!
Obviously I would never advocate pumping a 100Ah battery with 800A!!!!!!!! (Which after reading my post again - I suppose I did.)
UPS engineer http://www.powerups.co.uk
RE: Commissioning of New Battery Banks
"There is no limit on the charging current provided the float
voltage is set at the recommended value as the battery itself
will regulate the current, accepting only as much as is
required to reach float voltage."
UPS engineer http://www.powerups.co.uk