Found my old HP-34C from high school

[Steve Simpkin]

(09-21-2014 08:52 PM)jebem Wrote:  To minimize the risks, I would not power on the calculator while the charger is connected to the calculator.
More info here.

Unfortunately, since this is a 'C' model, charging it with the power switch off may not be safe as the CMOS RAM is always connected to power. The safest method is to take the batteries out and charge them in an external AA NiCad battery charger.