Q. What is an acceptable test reading relative to the stated capacity rating of the battery?
A. As most new nicads will test out to a capacity slightly greater than that printed on the side of the case one must aim for a value equal to or no more that 5% lower than this value. Dont assume that a 1000mAh rated pack that checks out to 500mAh is actually as good as a 500mAh pack. It is already 50% gone and the rest of its capacity will die soon!
Receivers will cause greater variations in battery loading due to servos operating at different times. As such, it is even more requirement to have a good nicad with the Rx than with the Tx.
Q. How often should nicads be cycled?
A.Cycling nicads is only necessary as part a true capacity, peace of mind checks.. If nicads are used heavily for long flying sessions there is less need to cycle. However, if a battery has been stored for several months, say during a winter lay-up, it is a good idea to cycle/test them a couple of times before use. Normally cycle checks should only be necessary four to five times a year on each battery. More often than that is considered of little benefit. Remember, it is always better to highlight pending faults at home rather than on the field. . .
Q. Can the analyser be arranged for dual voltage supply i.e., 240 & 120 volt supplies?
A.Yes, if required. Please state when ordering. Use of a 60 hertz mains frequency does not cause a problem either. All timings and ranges are processor controlled by quartz crystal and not dependent on any supply characteristics.
Q What happens if there is a diode (one way circuit) at the transmitter charge socket?
A.Certain transmitters have a diode in the charge connection. This will not allow a discharge through the socket. In this case it will be necessary to arrange the analyser to connect directly to the nicad battery itself. It is quite customary to add your own purpose connector to the nicad and keep this neatly tucked away under the battery cover.
Q. Does the analyser cycle/test two batteries at the same time?
A.No. The analyser goes through a complicated operation & test programme. It is not practical to arrange this for a dual battery function. As nicad analysis is a routine but casual function the need for checking more than one battery at a time causes no concern in practice.
Q. What other uses can the analyser provide?
A.Using the instrument to test batteries several days after they have been charged gives valuable insight to their shelf storage properties. Good nicads can retain 95% of their useful working capacity for long periods.
Q. How often am I able to use the Delta 4 charger?
A. It is quite in order to use the charger all the time with no ill effect to the batteries. It has been designed with this in mind. However, if your nicads do not get discharged, (not run down significantly during activity sessions) at least 5 times a year. then it is advisable to provide this discharge purposely yourself by one means or other. For similar reasons Delta 4 may be reluctant to charge either brand new or long-term stored battery packs. In these events an initial slow charge and couple of controlled cycles will allow D4 to be used satisfactorily from then on.
Q. Does Delta 4 give a full charge?
A. The Digital Delta Peak system used with the charger is very precise. As soon as the prescribed delta voltage occurs, for any particular battery pack, the charge will shut down. It may be noticed by those who use our analyser, that Delta 4 gives a marginally lower, (2 to 3% less) test result than that obtained from a traditional overnight charge. This is due to the fact that D4 does not overcharge. A more realistic charge is obtained with the D4. Overnight trickle charging can cause a pronounced cusp in the finally charged voltage. In practice this slight apparent extra has been shown to correspond to mere seconds of additional usage.
Q. How does Delta 4 cope with worn out or faulty nicad packs?
A.Where there are serious problems with a nicad Delta 4 chargers will reject those nicads, i.e., not charge. This will normally be apparent within half a minute of starting a charge. The added bonus from D4 in being able to detect pending failures over more simple forms of charging may just save that expensive model! Remember, overnight trickle charging will conceal nicad faults from an unsuspecting user.
Q. How long should I expect my nicads to last with prolonged use with the Delta 4?
A.Our extensive tests over many years have shown that the type of useful quick charge given by Delta 4 will have no ill effect whatsoever on the life of nicads. In fact, because the unit will tend to only used when it is needed rather than for repeated aborted sessions, batteries will generally be more reliable and last much longer than with repeated trickle charges. We can cite several instances where standard nicads with R/C equipment have lasted for as many as 2,000 full charges using D4 techniques.
Q. Would we use Delta 4 chargers on our own equipment?
A.Here at Mainlink, we are modellers too. Personally owned transmitters, (one of which is now over nine years old the other five), both have original nicad packs on board. Neither Tx has seen a slow charger since new, other than the casual routine cycle-test four times a year. The oldest Tx has now had well over 1600 charges and still performing as new. . .
Q. Is there any advantage in choosing to use a lower charge rather than any higher rate that may be available?
A.No. Actually there may be a disadvantage. Ideally we should chose an output at no more than a 2 to 3C rate, i.e., 2 to 3 times the battery rating. Delta peak charging does have a relationship with cell temperature. If charging is done too slowly ambient changes in room or day temperature can influence the end of charge drop-out. In theory a 600mAh nicad can be charged at well over 1 amp on our system but generally the wiring used with R/C equipment, (especially that in the Tx), cannot take a higher current. We regularly charge 150mAh nicads at 200 or 400mA. Even a 50mAh pack has been shown to suffer no ill effects when charged repeatedly at 200mA using Delta 4. At the other end of the scale a 2Ah pack can be charged at the 200mA rate over its required 12 hour period but this does defeat the object of having the charger in the first place!!
Q. Do the cells have to be vented?
A.No. Vented cells are a only a safeguard against overcharge. Once a cell has vented its performance will be seriously reduced. We have tested over 10,000 charges using our digital delta peak system on totally standard type cells. The technique has been shown so consistently reliable that overcharge and venting does not come into the equation. We do advise that Delta 4 is used only with normal cylindrical cells. We cannot offer any advice with its use with button cells.
Q. Can the cigarette lighter socket be used to run the Delta 4?
A.Basically the answer is yes. However, it is not unusual for these sockets not to provide the best all-time connection. It can be annoying to find the cigar plug has fallen out when this was not expected. Our advice is always to fit your own purpose connector to the car battery which will give the best results.
Q. Some transmitters have a diode in the charge connector. Does this matter?
A.No. the Delta 4 will still work correctly with or without a diode style transmitter. The circuit has been designed around this feature.
Q. Will the mains/12 volt Delta 4 still work the same from a car battery as with the mains?
A.Yes. The voltage boost takes car of battery voltage requirements and no difference will be found between either type of supply.
Q. Is there protection against supply battery or nicad reverse connection?
A.Yes. The 12 volt supply has total protection and the charge will not work if this has been done. No harm will come! Each battery output is similarly protected with any accidentally reverse connected nicads refusing to start. Other correctly connected outlets will continue to work normally. Each outlet is similarly protected against accidental shorting. However, note that the nicads themselves are not. . .
Q. How much power is consumed from the 12 volt supply battery during use?
A.This depends only on the number of cells in the pack being charged. The DDP contains a voltage booster that starts to operate only as required. For a 6-cell pack there is no boost. For a 7-cell pack there is some boost towards the end of the operation. Up to 14-cell packs the boost is introduced accordingly to maintain the charge current. Charge output is nominally at two and a half amps for all time. It is thus that up to 7-cell packs will cause a drain of approx. two and three quarter amps. When the booster is operating current drain can rise up to just below five amps for the maximum number of cells.
Q. Can two 7-cell packs be charged at the same time?
A.Yes. It is advisable to ensure that both packs are in the same condition, - state of charge. Packs should be wired in series so looking like a single 14-cell pack.
Q. Does it take any longer to charge a 14 cell pack than a 7 cell pack?
A. No. Essentially the charge current stays the same throughout the running time. Run time relates to the actual capacity of the battery being charged.