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ANSWERS TO MOST POPULAR QUESTIONS
Q. At what Voltage should I quit flying?
A. DURALITE SENTINEL Li-Ion: Stop fly voltage on a 7.4 volt pack is 6.9 volts measured with a one amp load.
A. DURALITE SENTINEL A123: Stop fly voltage is no less than 6.1 volts under no load. Because the discharge curve is not like a Lithium-Ion or Polymer battery, typical load testing cannot be used to determine remaining capacity of the A123 pack and is therefore not recommended.
Q. Why are there two leads on the "SENTINEL" packs ?
A. DURALITE SENTINEL Battery packs are supplied with two leads. The "yellow" colored connector lead is for charging which directs the charging current through our Stay Balance Charge Safe Circuitry™ allowing for a safe charging process. The second lead has a "black" colored connector and plugs into the switch harness as usual. This power lead is connected directly to the battery pack allowing for uninterrupted power to the receiver and servos.
Note: For the Duralite EXB packs please see EXB Questions & Answers below
Q. Why do I need a voltage regulator with the DURALITE SENTINEL 7.4 volt batteries?
A. The Lithium Ion technology has a higher per cell voltage than other batteries. The pack voltage is 7.4v which can be too high for the servos. Our regulator evenly distribute between 5.1v, & 6v. We offer 5.1v, 5.3v, 5.6v and 6v regulators with or without fail safe switches.
Q. Can I power my aircraft from the "yellow" lead?
A. No. The "yellow" lead is only to be used for charging your pack and checking the current state of charge. It should not be used as the power lead for your aircraft due to the Stay Balance Charge Safe Circuitry that the "yellow" lead is connected to.
Q. Why do I need a pack with Redundancy?
A. Redundancy creates a safety margin where if there is a problem with any cell in a pack the pack will continue to operate at half of the packs rated capacity at normal voltage. The larger and more powerful 4-cell packs are assembled with two - two cell packs in parallel (2s2p). This paralleling creates "in pack or Redundancy" with 4 cells working together to allow higher amp output for larger jobs. Any reduction of capacity becomes apparent when your normal pre-flight ground testing is done. We offer Redundancy in our larger and more powerful four cell packs including the DURALITE SENTINEL Lithium-Ion, LiFePo and the A123 packs.
Q. What is the life expectancy of a pack?
A. Service life is dependent on a number of factors. The most important factor being the depth of discharge (dod). The more deeply the pack is discharged the shorter the cycle life. We feel a reasonable life expectancy is 300 cycles and/or two years.
Q. What will happen if I leave my plane on accidentally?
A. Discharging below 5.5 volts can harm the battery pack! The low voltage shut off will protect your battery should it be left on. For this reason there is an optional Low Voltage Shut Off protector that can be installed to prevent battery damage as the low voltage shut off will protect your battery should it be left on.
Q. What is the maximum charge voltage?
A. DURALITE SENTINEL Li-Ion Packs: must not be charged over 8.4 volts. Using our DURALITE SENTINEL packs which incorporate the "Stay Balance Charge Safe Circuitry™", this is not a concern as the system is monitored and shut off at a safe level.
DURALITE SENTINEL A123 Packs: must not be charged over 7.2 volts. Using our DURALITE SENTINEL packs which incorporate the "Stay Balance Charge Safe Circuitry™", this is not a concern as the system is monitored and shut off at the required 7.2 volts.
Q. What should the battery voltage read once charged?
A. All 7.4 volt Duralite SENTINEL lithium packs should read 8.2 to 8.4 volts with no load and 7.5 volt or better with a 1 amp load measured through the black or yellow lead. 11.1 volt packs should be 12.4 to 12.6 no load and 11.8 or better with a 1 amp load.
Q. Can you test off either the black or yellow lead?
A. Yes you can. Both the yellow and black leads should read the same.
Q. Can you charge through the black lead?
A. Yes you can. Depending on the battery type the charge rate through the power output leads can vary. Lithium Ions can be charged up to 1C of the pack rating. The Duralite A123 packs can be charged up to 4C of the pack rating.
Q. I just installed my battery in my plane and today I checked it and it is dead?
A. Check to see if you plugged your battery into the unswitched regulator wrong. If an unswitched regulator is connected directly to the battery without a switch, the regulator will drain the battery. See regulator installation instructions.
Q. My battery tests OK but seems to go down in voltage quickly in the plane.
A. Check to insure the battery is not plugged into the regulator and the regulator into a switch. The regulator must have a switch between it and the battery otherwise the regulator will draw down the battery and eventually kill it. Also check to make sure there are no servos jammed or burnt out. If you are reading your voltage through the switch part check and compare the readings with the one taken directly off the black lead of the battery. Also check the reading off the out put lead of the switch (the one that plugs into the regulator) and compare to the black lead off the battery.
Q. I get a voltage reading off the black lead but not off the yellow and the charger does not seem to be able to charge up the pack.
A. The balance safety circuit has shut down. Contact Tech Support at 1-877-744-3685 or e-mail firstname.lastname@example.org for a Return Authorization.
Q. Do I need to cycle the battery packs?
A. No. But you should exercise them by running them down and charging them back up every 4 to 6 weeks if you do not fly regularly.
Q. Can I leave them attached to the charger?
A. No. Disconnect after 6 hours and unplug charger from its power source.
Q. Is it safe to charge overnight?
A. Never leave any battery unattended while charging. Always be present to monitor it.
Q. Do I have to use a regulator with these packs?
A. Yes for the most part. Most servo's are not able to 8.4 volts. There are a few exceptions however such as the Seiko servo's. Always consult the servo manufactures information.
Q. How do I mount the packs in a plane or helicopter?
A. Always soft mount them with foam and use Velcro straps to tie them down. Do not use wire ties such as as "zap strap" types of ties can damage the Stay Balance Charge Safe Circuitry built into each pack .
Q. I notice when I am charging the pack and the charge light has gone out when I go to touch the pack the charge light sometimes comes back on.
A. This is due to static electricity and is not a problem. Just measure the voltage of the pack and insure it is fully charged.
Q. My charger LED lights flicker near the end of the charge process.
A. This is a normal operation for our chargers as the battery nears the end of the charge cycle.
Q. What size battery do I need for my 33% plane?
A. There are a number of factors to consider when selecting the right set up for your aircraft. How many servos does it have? Are they digital? How long or how many flights do you like to fly in a day? See Applications Chart on the Technical Information page for more info. If you are unsure at to the correct setup for your aircraft contact Tech Support at email@example.com
Q. What size pack do you recommend for the ignition unit?
A. For twins 5200 mah packs. For singles 2600 mah packs. We also have Universal ignition power wire adapters for a number of motor manufacturers.
Q. What is the difference between a Power Box pack and an ECU pack?
A. The ECU pack has 30" of 14 gauge wire and comes without connectors on the power leads. The Power Box pack has only 16 gauge wire 12" long w/mulitplex connector.
Q. Can I charge through my switch that has a charge port?
A. Yes. On the SENTINEL packs use the yellow lead to the charge port. On the 'EXB' packs use the test lead to the port.
Q. How can I contact Duralite for technical support
A. firstname.lastname@example.org or call us toll free at 1-877-744-3685
Duralite EXB Lithium-Ion Questions & Answers
Q. At what Voltage should I quit flying?
A. DURALITE EXB Li-Ion: Stop fly voltage on a 7.4 volt pack is 6.9 volts measured with a one amp load.
A. DURALITE EXB A123: Stop fly voltage is no less than 6.1 volts under no load. Because the discharge curve is not like a Lithium-Ion or Polymer battery, typical load testing cannot be used to determine remaining capacity of the A123 pack and is therefore not recommended.
Q. Why are there 3 different leads on the EXB packs?
A. One is the power output lead that will go to your RX, ECU or PowerBox. One is the balance tap that will go to your balance charger (such as the TP-610C, etc.). The last one is a test or charge lead so you don't have to unplug your power lead.
Q. Can I charge through the balance tap?
A. Only if you are using a charger such as the FMA Cell-Pro that charges each cell in this manner. Check with your charger manufacturer.
Q. My EXB pack will be buried in the plane. Do you make an extension for the balance tap connector?