The Superseder series of Battery Charger-Analyzers, and other similar products manufactured by JFM Engineering, are designed to be safe instruments for the batteries as well as for the operator.

The Superseder starts with a highly regulated output current which is independent of battery voltage and line voltage. In addition, a Monitor circuit shuts down the operation if it detects that the current differs from the programmed current by more than one amp. This protection is enhanced by a temperature plate which shuts down the charge in case of battery overheating. Ultimately, a mains breaker and a current limiter serve as final protection in case of an internal malfunction.

There are additional protections in case of reversed polarity connection and open circuit protection. 
In case of a reversed polarity connection (as it would occur when charging a single cell) the Monitor Circuit will not allow the system to start, thus preventing damage to the cell/battery.
In case of an open circuit (as it would occur with a missing link or the cable not connected to the battery), the Monitor Circuit shuts down operation when it senses that there is no load to absorb the output current. Similarly, a momentary interruption of the current, as with an intermittent connection (loose link) will result in an immediate system shutdown.

Finally, the battery voltage is continuously sensed by the Monitor Circuit, which will shut down the charge in case of battery overvoltage.

As a complementary precaution, the control circuit is backed up by an internal rechargeable battery that protects the integrity of the operation in case of power failures. Whether the power failures are momentary or prolonged, the Superseder will recover and continue with the programmed operation.

The precision of its control circuits and the protection of the monitor circuits are the basis for the operational reliability of the Superseder. It can be operated unattended with the confidence that the system will perform safely and completely.

Why risk damaging your batteries with equipment of inferior performance?

With over 23 years in the market, the Superseder has established itself as a most reliable instrument. In addition, it is backed-up by a manufacturer which guarantees immediate response in case of application problems, overnight shipping of spare parts, fast repair turn-around time and efficient product upgrading. 

For information, contact Aero Quality Sales at (800) 288-1954 or JFM Engineering at (305) 592-2272

C2 - The Fallacy of Reflex Charging

3 February 2003

Much has been said over the past 20+ years about the advantage of “faster” Reflex charging over the conventional constant current method for the testing of Nickel-Cadmium batteries. 

The truth is that even if the Reflex method succeeds in delivering a faster main charging (the first 100%), there is still a remaining period of topping constant current (the additional 40%) which is necessary to determine the charge acceptance condition of the cells. 

In order to understand the issues we must first determine what is meant by battery charging in the process of battery testing. 

The main objective of battery testing is to determine if the battery is performing according to the specifications of the original manufacturer. There are two parts to this testing, one is capacity and the other is charge acceptance. 

In the capacity test, the battery is discharged at the rated A-Hr current (C1) for one hour. The battery passes if the voltage of each of the cells is 1.00V or more at the end of the hour. Conversely, the battery fails if the voltage of any one cell drops below 1.00V (even though the total battery voltage may still be above the minimum). 

This test, however, requires that the battery be charged fully and for all of the cells to develop the proper charge voltage. A full charge is made up of 140% of the battery A-Hr rating, most often delivered as a main charge (at C/2) to provide 100% and a topping charge (at C/5 or C/10) to provide an additional 40%. Cell voltages exhibit typically 1.60V at the end of the topping charge and must have a minimum of 1.50/1.55V 

Any cell which fails to reach the minimum peak voltage, or any cell which exhibits a voltage drop after having reached the required peak voltage, is suspected of having separator failure particularly if there is warming up in excess of 102^oF. 

During this time, the cell voltages not only must reach the proper voltage but must do so without any heating. Typically, cells with separator failure will have voltages that will not rise above 1.45V and may also exhibit significant warming-up. 

Note that any battery will exhibit some warming up if overcharged, particularly if it is a worn out battery (higher internal resistance). Since Reflex charging can result in significant battery warming, particularly on older batteries, it becomes hard to determine if the heating is because of the condition of cells or simply because of the charge method. This is also why batteries must not be recharged immediately after discharge, for there is considerable normal heating during discharge. Consequently, batteries must be allowed to cool off on their own, which will take several hours, or they must be force cooled (refrigerator) if immediate recharging is needed.  

Therefore, the Topping Charge period is a crucial part of the certification process because the readings taken during this step will determine the real condition of the cells, even though the preceding Capacity Test may have been successful.  

The comparison of efficiency between a Reflex charger and a Constant Current charger such as the Superseder is as follows: 

A typical battery requires 2 hours of main charge plus 4 hours of topping charge, for a total of 6 hours. With a Reflex unit, the main charge could be shortened to one hour but the 4 hour Constant Current Topping charge must still be performed. In comparison, the Superseder requires 6 hours for a full charge. It would appear that the Reflex charger has the better time but it is not so, for the Superseder can do TWO batteries simultaneously thereby resulting in a 3 hour per battery performance. 

The final numbers then are, one battery in 5 hours with a Reflex charger or two batteries in 6 hours with the Superseder. 

Finally, we must look at the long term effect of the charge method on the battery. Battery manufacturers specify in their manuals that batteries be charged for certification with the constant current method. This is so because the constant current method is the safest and most accurate one to determine the condition of the battery. 

Attempts to accelerate the charge process can and will result in false results and may be detrimental to the longevity of the battery. Any attempts to shortchange the process (as in by not subjecting the battery to the Constant Current Topping Charge) becomes an incomplete charge, clearly not in conformance with the requirements of the battery manufacturer.

See the article "The Superseder III plus the BTAS16 equals great performance in the Battery Shop" for details on how to achieve two and three battery testing efficiency.

C3 - The Superseder III plus the BTAS16 equals great performance in the Battery Shop

13 March 2003

As we are required to do more with what we have or even with less in terms of resources, we must look into how equipment can help us achieve good results with improved efficiency. 

The Superseder series of Charger-Analyzers have been contributing, for the past 20+ years, to the efficiency in the battery shop by virtue of its two battery capability. 

Since the earliest model, the Superseder has been capable of charging two batteries thus providing a considerably performance improvement over the single battery method (see “The Fallacy of Reflex Charging”). 

In addition, the Superseder has also been capable of discharging two batteries (at reduced rates), hence also improving the performance (see the specifications for the Superseder III). 

Capacity testing two batteries, however, is not as convenient for it requires close monitoring of battery voltage on an individual basis, thus reducing considerably the efficiency. This is because the Superseder can only act on the total voltage, thus, if one battery fails capacity, the instrument will not act on it if the voltage that it measures is greater than the voltage set by the number of cells. 

But, the combination of the Superseder and the BTAS16 can now deliver full and even greater performance with multiple battery testing. 

Since the battery voltages (total and individual cells) can now be monitored in detail by the C-Scan component of the BTAS16 Automated Battery Test and Analysis System, it is now possible to connect as many batteries as the Superseder is capable of handling (up to 50 cells), and obtain accurate and detailed individual battery test results in charge and in discharge.

Examples: 

1.      Testing of two SAFT 23180 batteries.

Capacity:

The 23180 battery is a 20 cell, 23 A-Hr battery that requires discharging at 23A for 60 minutes to a voltage no less than 20V.

The Superseder III can handle up to 30A for batteries of more than 22 cells therefore it is perfectly suited to discharge two 23180 batteries.

Since the C-Scan will be reading the cell and total battery voltages, the mode to select is discharge, as opposed to capacity, to avoid stopping if the total voltage falls below 40V.

At the end of the one hour discharge, the C-Scans (one for each battery) will have taken all the necessary readings for the two batteries.

Charge:

Connect the batteries to the Superseder and program the instrument per the manufacturer's requirements (Main charge of 11.5A for 2 hours and 2.3A of Topping Charge for four additional hours). 

At the end of the one hour discharge, the C-Scans (one for each battery) will have taken all the necessary readings for the two batteries.

2.      Testing of two SAFT 4076  batteries.

The 4076 battery is a 20 cell, 36 A-Hr battery that requires discharging at 36A for 60 minutes to a voltage no less than 20V.

Since the Superseder III can handle only up to 30A for two batteries (the previous models are limited to 20A) it would appear that it is not possible to discharge the two 4076 batteries in series at 36A. But, it is possible to simply lengthen the discharge time to reach the proper A-Hr figure. If we originally require 36A for 60 minutes, then at 30A the discharge time must be stretched to 72 minutes.

In the BTAS16 software, there is a mode, called “Custom Capacity” where any discharge time (in minutes) can be entered, thus satisfying this and any other time requirements.

Charge:

Program the Superseder per the manufacturer's requirements (Main charge of 18A for 2 hours and 3.6A of Topping Charge for four additional hours). 

At the end of the charge, the C-Scans (one for each battery) will have taken all the necessary readings for the two batteries.

3.      Testing of three MARATHON 7-75M³ batteries.

Capacity:

The 7-75M³ battery is a 7 cell, 75A-Hr battery that requires discharging at 40A for 115 minutes to a voltage no less than 7.00V.

Since three batteries equal a total of 21 cells, the Superseder III will discharge the batteries at the required current.

Since the C-Scan will be reading the cell and total battery voltages, the mode to select is Discharge, as opposed to Capacity, to avoid stopping if the total voltage falls below 21V.

At the end of the 115 minute discharge, the C-Scan (one for all three batteries) will have taken all the necessary readings for the batteries.

Charge:

Program the Superseder per the manufacturer's requirements (Main charge of 40A for 2.5 hours and 8.0A of Topping Charge for four additional hours). Note: since the Superseder cannot handle fractions of an hour, program 3 hours of Main and transfer manually from Main to Topping, or simply use 2 hours of Main Charge (The Superseder will properly charge the battery with only 2 hours of Main). Note also that Superseder is capable of charging 2 sets of these batteries (total of 6 batteries).

 At the end of the charge, the C-Scan will have taken all the necessary readings for the three batteries.

4.      Testing of two SAFT 43B034LB03 batteries.

Capacity:

The 43LB034LB03 battery is an 11 cell, 35A-Hr battery that requires discharging at 35A for 51 minutes to a voltage no less than 11.00V.

Since two batteries equal a total of 22 cells, the Superseder III will discharge the batteries at the required current.

Since the C-Scan will be reading the cell and total battery voltages, the mode to select is Discharge, as opposed to Capacity, to avoid stopping if the total voltage falls below 22V.

Note that the Superseder is capable of discharging two sets of batteries (total of 4 batteries) if the current is reduced to 30A or less and the discharge time is lengthened accordingly.

At the end of the discharge, the C-Scan (one for two batteries) will have taken all the necessary readings for the batteries.

Charge:

Program the Superseder per the manufacturer's requirements (Main charge of 17.5A for 2 hours and 3.5A of Topping Charge for 4 additional hours). Note: the Superseder is capable of charging 2 sets of these batteries (total of 4 batteries).

 At the end of the charge, the C-Scan will have taken all the necessary readings for the three batteries.

In conclusion, whether for charging or discharging, the combination of the Superseder and the BTAS16 can not only speed-up the battery testing process but it will also do it more accurately, thus truly improving the efficiency of the battery testing process. 

C4 - The new Intelligent Charger Analyzers and the BTAS16 give you total control of the battery testing operation

27 April 2009

The new Intelligent Charger-Analyzers and the BTAS16 will give you an unprecedented degree of control of the battery testing operation together with an increased accuracy and efficiency. 

The microprocessors of the new Intelligent Charger-Analyzers (SupersederXG and 24-400xg) can communicate with the BTAS16 system thus providing monitoring and control of their operation, above and beyond what is possible today with the Superseder III.

C5 - Series Charging of Nickel-Cadmium Batteries

Series Charging of Nickel-Cadmium Batteries

Can Nickel-Cadmium batteries be charged in series?

Yes and no.

Yes if with constant current; no if with other methods (constant voltage, etc.)

A more complete answer, however, depends on the purpose of the charging.

If the purpose is to simply charge a discharged battery, any method available will do.

But, if the purpose is to charge a battery for test purposes (to determine if the battery is airworthy) then constant current is the only way (as established by the manufacturers of the batteries).

When a battery is charged in constant voltage (or other voltage dependent methods) then the individual cells that make up the battery can easily become imbalanced[1]. This is one of the reasons why a periodic deep cycle is needed.

When a Nickel-Cadmium battery is charged at constant current, all cells are free to develop a voltage that becomes indicative of their charge acceptance.

It is for this reason that Nickel-Cadmium batteries can be charged perfectly well in series[2].

Why charge batteries in series? Strictly for efficiency reasons. The typical charge time for a Saft battery is 6 hours[3], therefore, if two batteries can be charged simultaneously, there is a significant gain in time.

Charging two batteries in series requires a higher capability in the Charger-Analyzer and a higher safety margin. The Superseder was designed for both. It can provide constant current charging from one cell up to 50 cells and it can only output current while connected to a battery (no dangerous “hot” terminals).

What about the task of measuring 40 cells, not just 20?

Yes, measuring the voltage on each cell is laborious and error prone but it can be done (not just on 20 cells but on all 40 – there is plenty of time). To alleviate this burden, we offer the BTAS16 Battery Test System that automatically takes all necessary measurements, accurately and efficiently (see http://jfmeng.com/btas16.htm).

What about discharging two batteries?

Discharging of two batteries, for the purpose of Capacity Testing, presents a different situation. At constant current, it basically does not matter how many batteries are connected but there is a power dissipation limitation. The Superseder III is limited to a maximum of 60A for one 24V battery or 30A for two 24V batteries. At a higher voltage and/or current, the heat dissipation will exceed the cooling capability in the load banks.

Yes, it is possible to lower the current and extend the time to accommodate batteries that would otherwise exceed the power dissipation limit, but it may be necessary to account for possible performance differences at the lower current.  

But, there is a more fundamental issue here. Capacity testing is not simply based on a battery terminal measurement; it requires that all cells be measured, because the battery will fail capacity the moment that any one cell fails capacity, thus requiring rapid measurement of all cell voltages. It is already quite demanding to quickly monitor 20 cells, let alone 40 of them.

The BTAS16 system again comes into play by providing an easy method to measure all cells, not just 20 but 40!

Summary:

Series charging of Nickel-Cadmium batteries is perfectly normal provided that it is done with constant current.

Series discharging, however, is not that simple, as it is affected by other factors that limit the gain in testing efficiency.