Totally anecdotal reply. I have a Fluke 97 Scopemeter I purchased perhaps ten years ago. It has a wall-wart supply that recharges internal C-cell batteries, but it can also run on alkaline or other non-rechargeable C-cells. To the best of my knowledge, it is up to me to remember what batteries I have in there, there is no switch at all. If I want to run off mains power, I have to either have rechargeable batteries, or remove the non-rechargeables. I don't know much about this, but I seem to recall that it took a long time to recharge the Ni-Cds. Maybe they got around the hazard by having a low enough charging current it wasn't a hazard?
From: "Chris Maxwell" <chris.maxw...@nettest.com> Reply-To: "Chris Maxwell" <chris.maxw...@nettest.com> List-Post: emc-pstc@listserv.ieee.org Date: Wed, 14 Apr 2004 13:44:29 -0400 To: "EMC-PSTC Internet Forum" <emc-p...@majordomo.ieee.org> Subject: Rechargeable and Non-Rechargeable batteries Hello good people of the group. We generally test our equipment to EN 61010-1. We usually have rechargeable batteries in our product; and they¹ve never really been a safety problem, other than adding diodes and ³approved² charging methods. Usually the batteries that we use are so oddly shaped, that there is a very small risk of a customer putting in the wrong type of battery. Where I¹m really lacking in knowledge (among many areas) is when it comes to handling standard sized, yet rechargeable batteries. For instance consider the following example: 1. A case designed with a wall wart power input and a spot for AA sized batteries. 2. The product would be designed to recharge AA sized NiMh batteries, if installed. 3. Alternatively, the user could install AA sized alkaline batteries; but they would have to set a switch in the battery compartment to disable the charge circuitry. Assuming all warning labels and documentation were in place? Is this a generally accepted practice; or is it too unsafe to require the customer to throw a switch. That¹s my specific question. Now a more general issue. Up until now, I¹ve learned about battery safety indirectly. As in, I submit a product to the lab, make any required changes (diodesŠ) and ship product. I haven¹t yet found a reference that outlines the safety requirements for batteries in EN 61010-1 or EN 60950 equipment. Is there something that I¹m missing in the standard? Or, is this one of those issues that is handled by experience, agreements and memoranda among the various safety certification agencies? Alternatively, is there a stand-alone IEC specification regarding battery safety? As always, the collective time and energy of the group is appreciated. adTHANKSvance Chris Maxwell Design Engineer Nettest
