The Purssang Energy Transfer Box F.A.Qs

How do I get the best efficiency in solar mode?

Always check that the battery ends and contacts  are clean and grease free. Always check the cables are the correct type and properly fitted.

Maximum efficiency will be achieved during solar charging operation when the solar modules are oriented directly to the light source and the base unit kept in the shade.

External devices will charge most effectively if the following points are observed:

1. The ETB charger is equipped with charged batteries.
2. The solar radiation is approx. 50-100% of the maximum value (Max value is 1000 W/m²: which is the average solar energy level obtained through midday sun in Central Europe from March till October.).
3. The Output power switch is kept in position 1 ( 1..2 watts ).This is the optimum position for all mobile phones and most other mobile devices. Position 2 ( 2.5 watts ) or Position  3 ( 4.0 watts) should only be used for external devices  which require a higher charging current.

Due to the patented power control system in the ETB a constant output power is provided to an attached external device even with varying light irradiation. Excess solar energy is stored in the internal batteries and energy is taken proportionately from the batteries during periods of low solar radiation.

What is the best output power for my devices?

The lower the output power for the operation or charging of external devices, the higher the degree of effectiveness. Some devices, however, need a minimum operating or charging power, above which they accept operation or charging. It is therefore recommended to start in switch position 1 (1.2 watts) first and to change to position 2 (2.5 watts) or 3 (up to 4.0 watts) when appropriate for the device being charged. Switch position 3 should be used only as an exception and never for mobile phones.

Which kind of power Input source can I connect to the ETB?

The ETB will tolerate up to 6V and 1.8A at the DC-input socket. However , we recommend that only the original mains power adaptor is connected to the ETB. Use of any other power source will invalidate the product warranty.

Which kind of power Output supply  can I connect to the ETB?

External  devices which require up to 16V, can be connected, however, the current available will be highly limited internally. Consequently we can only recommend that only ETB output cables and adaptors are used to supply power to an external device. The use of non-original cables or plugs will, understandably, invalidate the product warranty.

What happens if I try to use solar power only to charge an external device without batteries in the ETB?

Many mobile devices consume a relatively high current internally if they are attached to an external battery charger. This pure loss current is typically 20 to 30 mA, it can, however, be up to 80 mA for mobile phones and between 20 to 100 mA  for PDA’s (depending on the device). A direct operation of such devices without internal battery buffering ( i.e., without batteries in the battery holder of the ETB ) should therefore always be carried out only in full sunshine as otherwise the charging current could be lower than the current consumed by the external device. The possible consequence of this is that the external device discharges itself internally despite an external charging current!

Which batteries can I use with the ETB? 

The ETB 20 and ETB 30 chargers are ideally suitable for operation with 2 or 4 AA or NiMH batteries with a capacity as high as possible. (2 or 4 AAA batteries can be charged with the optional battery adaptor).Due to the intelligent charging control using different charging modes of the ETB any given battery type is charged optimally including NiCd batteries and RAM cells. NiCd batteries should not be used in AAA form since the capacity falls below the permissible lower limit. RAM cells are not suitable for frequent charging and only for low discharge currents. There is danger of injury and of damaged RAM cells in the case of a device defect. The use of RAM cells is therefore not recommended and they are used entirely at your own risk and are excluded from the product warranty.

What happens to damaged and non-specified batteries?

Batteries with an internal short circuit can only be charged with a minimal current and can be revitalised only in exceptional cases. Therefore, if a charge condition of at least 20 - 50 % ( LED2 flashes) is not achieved after a charge time of several hours with an external mains adapter, the batteries should not be used any more in the ETB charger. The use of other batteries than those listed in the Instruction manual, such as batteries with a lower capacity, non-rechargeable batteries or other battery systems, as well as of RAM cells is excluded by the product warranty.

Can I use non-rechargeable batteries in the ETB?

Only In Strictly Emergency situations - Non-rechargeable batteries can be used in the ETB ONLY to discharge their energy into an external device. NEVER try to recharge non-rechargeable batteries in the ETB.

How damp-proof and tough is the ETB?

The ETB was designed for both outdoor and indoor operation, it can, therefore withstand scratches and light shocks similarly to other mobile devices (mobile phones, PDAs etc.). It is not, however, guaranteed against strong mechanical shocks such as being dropped onto a hard surface. The optional protective rubber cover (standard on the ETB 30) offers increased shock protection. If water penetrates the case of the charger the batteries must be taken out and the mains adapter must be immediately disconnected. The ETB should then be positioned so that all the water can drain out and air can circulate freely (. Never place the ETB on a hot surface to dry it out! ) After thorough drying, normal operation should be possible again. High humidity, e.g. in tropical regions, is not a problem.

Do I have to protect the solar module of the ETB?

The surface of the solar module should be protected from scratching and impact .metal objects should not be placed on it .Occasionally clean with a soft damp cloth gently wiped across the surface. Never use an abrasive cleaner or harsh material to clean it.

How does the ETB withstand extreme heat and freezing Temperatures?

The ETB has a number of internal protective measures to protect its internal components together with externally connected devices from extreme temperatures. It can therefore happen that the charging process shuts down at ambient temperatures above approx. 45°C - especially when the ETB is on maximum load, e.g., when using the mains adapter with simultaneous charging of AA batteries and the operation of an external device with the Power switch in position 3 (4 watts).If the base unit is in direct sunlight, the internal temperature rise is accordingly higher and a shut down can take place earlier. Therefore, you should always make sure that the base unit is shaded by the solar modules. Basically, operation inside overheated vehicles (Internal temperature above 45°C) or in other enclosed hot situations is not recommended. Shutting down of the charging process is also possible at ambient temperatures below approx. 0°C because otherwise the batteries could be damaged. After such a temperature shut down all LEDs are turned off. Normal functioning will resume once the ambient temperature returns within normal operating range.

What happens in case of short circuit or over-voltage?

The ETB is continuously protected by its intelligent charging system against an external short circuit at its DC input as well as at the adapter cable output and will switch its internal and external power supply off if this occurs. Such a situation should nevertheless be carefully avoided by the user and attention paid to the proper function of attached external devices. The charger is protected against excess voltage at its inputs and outputs according to the prevailing EMV guidelines. Providing an external voltage charge at the output or by using a non-original equipment mains adapter at the DC input can lead to damage to both the charger and any device attached, which is then excluded by the warranty. This also applies to the connection of inductive loads at the adapter cable which lead to the existence of output voltages of more than 16 V as well as the use of non-original adapter cables.

Which safety precautions should be regarded during operation?

For safety as well as energy saving reasons all mains powered battery chargers – including the ETB when using the mains adapter - should not be attached to the mains continuously over several days. In case of an internal defect the ETB intelligent charging system limits the charging current to a harmless value, however, an overcharging of the internal batteries cannot be completely excluded in these circumstances. If the ETB shuts down for this reason all LEDs are turned off. If all the LEDs are switched off despite charged batteries with a device is attached to the input or output  sockets there is an internal defect, a faulty device attached  or excess temperature .in the  batteries.  In this case immediately remove all attached devices as well as the internal batteries! These measures also apply if the batteries or other parts of the device or external components are so hot that they cannot be touched. (Approx. 70°C) or in case of fire or smoke. Do not touch the battery contacts or the inputs and outputs with metallic objects since short circuits could arise!

What is the expected life time of the ETB?

Apart from the batteries, hardly any component of the ETB has a restricted life time. In the course of normal outdoor usage, the case as well as the solar module will obtain some light scratches. This has no effect on the performance though. It may be necessary to replace the adapter cable, as it may suffer from the normal wear and tear of frequent usage. If treated correctly, good quality batteries can last up to ten years at 25°C, however a realistic lifetime of 4-6 years should be expected dependant of course on the usage rate... The batteries should be disposed of at the appropriate waste disposal station. In the unusual case of discarding the entire ETB unit it can be treated as regular electronic waste.

What maintenance does the ETB require?

For effective operation of the ETB  the following simple maintenance  measures should be carried out regularly:

1. Clean battery contacts regularly, if necessary with cleaning liquid or contact spray.
2. Clean hinge areas  in cases of visible contamination, e.g. after use in very dusty surroundings, spray lightly with contact spray( Wd40 etc) and open and close the solar modules smoothly several times to clean the hinge pins which also act as electrical contacts. In severe cases of contamination the solar panels can be removed and the hinge contacts cleaned individually. Advice on how to do this is available from Purssang Technical department on request.
3. Remove contamination on the solar modules by very gently wiping a soft cloth moistened with lukewarm water ONLY. Do not rub the panels with coarse fabric or use any abrasive cleaner!
4. Check cables and peripheral components regularly for defects and damaged insulation etc...