I use quite a few appliances that take batteries, from AAA through to 9V block batteries. The only economical way to operate electrical goods that are battery powered is to utilise rechargeable batteries.
Having so many different types of rechargeables in the house, I needed a universal charger that would charge them all. I selected the 'Vanson Speedy Box' as it appeared to have several advantages over the competition.
The Vanson Speedy Box is an attractive unit. The rounded matt black plastic box has cells for up to four AAA, AA, C, D or as well as two 9V cells and, due to the design of the box, it can charge different sized batteries at the same time (although 9V batteries cannot be charged at the same time as other sizes).
The Speedy Box is marketed as an 'intelligent charging unit'. There are several reasons for this claim, which together make the unit much safer to use than 'dumb' chargers:
i) Faulty batteries are detected automatically. The charger will not charge these and displays a warning on the box.
ii) The charger has overcharge protection; charging ceases when the battery is fully charged (having separate 'slots', charging ceases on each slot when a full charge has been reached).
iii) If the user puts the batteries in the wrong way round, again charging will not proceed.
iv) The unit also protects against short circuits.
Batteries can contain a large amount of energy, the intelligent charging system protects against overheating, damaged batteries, and possible fires.
This is not the fastest charger on the market (this is deliberate, to avoid unsafe charging), but it is fast, due to a three stage charging process.
The Speedy Box can be used for both Ni-Cd and Ni-MH rechargeable batteries. The horrendous 'memory refresh' issue of Ni-Cd has seen them replaced in most uses by Ni-MH, but they are still around. To combat the memory effect, the unit has a 'discharge' button. If this is pressed, the batteries in the cells are fully discharged within 30 seconds. Charging from 'empty' is recommended for Ni-Cd batteries, but can also be useful, on occasion, for Ni-MH cells.
The design of the battery holders is extremely good and manufactured to a high standard. Each size of battery is securely held, ensuring a good connection for charging. When batteries are put on charge, a red LED is lit on each occupied cell. This changes to a green LED once that battery is charged. The separate charging circuits ensure that all the batteries will be charged to the same level.
This charger is, as can be seen above, very easy to use as all of the charging features are automatic. All the user has to do is put the batteries in and turn the unit on. The microprocessor controlled charger ensures that the batteries are quickly and safely charged to the required level, then indicating when charging is complete.
Although almost 'idiot proof', one hazard remains: the user putting non-rechargeable batteries into the unit. The Speedy Box cannot prevent this happening, and doing so could result in damage to the charger, or even an explosion.
The Vanson Speedy Box is not cheap at around £42. Due to its flexibility (charging most sizes of battery), its speed, and its safety features, this does still represent good value for money. I've had mine for 12 months and would not now want to go back to a 'dumb' charger.