Frequent Asked Questions (FAQ)

Q1. What is the definition of “cycle use” and “standby use”?

“Cycle Use” – direct power source:
It can provide the power supply to power tools, portable electronic products. It can also be used for cycling charging and discharging usage such as electronics motorbike or vacuum cleaner.
“Standby Use” – back up power:
Mainly used for emergency power to avoid future damage that may be caused by a sudden power outage.

Q2. Why is the charging voltage for “cycle use” higher that the voltage used for “standby use”?

Cycle use is a direct power source. The charging time can not be too long for a user. The higher charging voltage can provide longer maximum charging current during the charging period. (A full charge should be Charging AH / Discharging AH = 110% ~ 120%.)

Q3. What is the effect of different charging currents on batteries?

A higher charging current can shorten charging time. However, a higher charging will cause more heat and gas inside the battery and could result in thermal runaway. The suggested charging current for our battery is 0.3C.

Q4.What does “100% discharge” and “50% discharge” mean?

To illustrate, use a fixed load to discharge (W or A). If the discharge time is 10 minutes until the voltage comes down to the final voltage then we can say it is 100% discharged. In the same way, if the discharge time is 5 minutes then it is 50% discharged. The table below shows the relationship between “discharge current” and “final voltage.”

Q5. Thermal runaway will happen if a battery is operated under 40 – 50ºC for a long period. How will thermal runaway effect a battery?

Thermal runaway in a battery will cause excessive heat generation, battery swelling and result in a dangerous condition. SUNEOM does not recommend the use of our batteries for a long time under a 40 – 50°C (104 – 122°F) environment. The battery should not be used close to a heat source or in a high temperature application.

Q6. How can you check a battery’s performance?

Different usage applications will use different methods for evaluating a battery’s performance. Using a 20 hour rate or the 10 hour rate, you can use 0.05CA or 0.1CA to discharge the battery until the battery reaches a terminal voltage of 10.25 volts. You can then calculate the amp hours to see if the battery fits the specifications or not. For a 5 minutes rate, such as the SUNEOM12V5Ah, you can use a 21 watts/cell discharge till the terminal voltage reaches a terminal voltage of 9.6 volts and then measure the discharge time to see if it meets the final specifications or not.

Q7. If a battery is stored for 6 months at 30°C (86°F) since its manufacturing date, how can you bring the battery’s performance back to 90% in 1 hour’s time? Will that procedure cause any quality problems?

A brand new battery stored for 6 months since its manufacturing date will loose 30-35% in performance. You can use 0.3CA, C.V.=14.7V/PCS to charge for one hour. The battery should then return to normal performance.

Q8. How can the conversion be made between “watts (W)” and “amp hours (Ah)”?

W=I x V = 4I (15 minute rate) = 2CV = 2V

Q9. Why “zero voltage” might happen?

Zero voltage means there is a broken circuit. There could be several reasons for a zero voltage state.
1.There could be a broken electrode column
2.Welding defects of the partition
3.Welding defects of the terminal

Q10. How can you tell if a battery is good or bad?

You should first check the battery for defects such as a broken circuit, a short, or a broken container. If an outward problem is not apparent, then you will have to check the battery’s capacity using known measuring techniques to ascertain the problem.

Q11. Self-discharge will reduce a battery’s performance gradually. What is the best storage environment to minimize self-discharge? How can a battery be reverted to normal performance?

A battery will drop its performance during the storage period automatically; this phenomenon is denoted at “self-discharge.” This state of “self-discharge” cannot be avoided.

We suggest recharging batteries during a storage period using the guidelines outlined below.

Normally you may not get 100% performance back after storage during the first recharge. That means those batteries may need more than one recharge cycle. Please discharge then recharge
for 3 cycles.

Q12. What is “over-discharge” and what is it’s effect on a battery?

If the final voltage is lower than the standard final voltage, we can say the battery is “over-discharged.” The state will affect the battery’s quality very seriously.
1.The “over discharge” state will cause overuse of active material. The composition of the battery will be changed by the over discharge. There will be degradation of the plate.
2.It may bring out too much or large amounts of lead sulfate (PbSO4) which could cause damage to the plate structure. A recharge may not bring the full performance of the battery back.
3.Recharging after over discharging may lead to short failures.

Q13. What are the advantages of using SUNEOM batteries?

1.Low self-discharge rate, superior performance
2.High quality and competitive price of batteries.
3.Batteries for all applications, UPS, power tools, telecommunications, etc.
4.Service supported after purchase by SUNEOM

Q14. Why are there different plate designs for different batteries?

1.Customer demand
2.Special requirements dictate thickness and dimension
3.Our engineers will create the best design based on usage and application

Q15. What is the effect of “floating charge voltage” in relation to battery life?

Q16. You can use a serial or parallel connection to discharge a battery. What is the difference with a single “battery” discharge?

In a perfect condition, the discharge rate will increase with the number of batteries connected in series or parallel. However, there will be some lost during the energy transmission by impedance such as a wire or an interface. The numbers listed in our literature are based on average numbers; the actual performance might have some variations.

Q17. If a battery fails, what will be the indications?

1.Lower performance
2.Low voltage
3.Cannot charge/recharge
4.Swelled container
5.Acid corrosion