For power hps unit can be used with either ordinary alkaline batteries or rechargeable type NiCa or NiMH batteries AA size, 5pcs, certainly identical on capacity, 800mA/h, as recomended Velleman, or higher. The higher the capacity of the rechargeable batteries, the longer the autonomy of the unit. If you, certainly, have AC/DC adapter and frequently use your scope autonomy, differently it will be by empty expenditure of money.
When the unit is OFF, the charging time for 800mA/h type batteries will be approx. 12 hours.
Charged current 90mA.
Do not use adapters with a voltage more than 9 volt DC for unregulated and more than 12volt DC if regulated, because circuit of charge, inside of scope, use BDP31 transistor , total power dissipation BDP31 transistor is 1.35Watt for temperature
≤25° and at the greater current of a charge overheat transistor and damage charge circuit.
Max. charged current = 1.35W/12V=112,5mA, current limited 90mA for long time of charge.
The higher the capacity of the rechargeable batteries, requested more time for charge.
Better use special automatic charge unit with function ΔV for rechargeable batteries of higher the capacity. It will reduce time of a charge up to 3-5 hours, and relieves that of troubles.
Remember: scope, even if power OFF, yet consumption small current < 0.6mA (standby current: < 600μA), it is enough of it completely to unload batteries and to cause outflow of a liquid from salt batteries or discharge rechargeable batteries more than 1 volt per cell, it considerably will reduce life time of rechargeable batteries, if long period scope not used.
Remove all batteries, if unit not use of long time, more than 10 days.
Avoid to use salt batteries MgZn type, as “0% Cadmium”, “0% Mercury”, because it may cause leakage, fluid from batteries is very agressive and can damage inside electronic components and printed board of scope.
Better use alkaline batteries. Don’t use different type alkaline and salt of batteries or new and used together.
Remove all non-rechargeable batteries when connecting an AC/DC adapter, because if recharge this batteries type, it will cause increase of a current of consumption from the adapter and through the charge circuit, more, than 112mA circuit of charge may overheated and damaged, also batteries may overheated or leak.
In this cases Velleman not provide warranty.
In quality the charge devices and power supply for scope can be used Velleman kit k1823 or k2570, previously establishing output voltage to 12V.