I would think that a small resistor, say 50 ohms, in series with each battery being charged work? ----- Original Message ----- From: "Ariel Rocholl" To: "Microcontroller discussion list - Public." Sent: Tuesday, February 19, 2008 1:24 PM Subject: Re: [EE] Batteries in parallel >I should have clarified that battery charge process is done > separatedly (in other words, batteries are plugged in completely > charged already). > > 2008/2/19, Bob Axtell : >> You cannot do this because you cannot charge either battery correctly. >> You MIGHT be able to do something with a latching relay, but you will >> need >> to control it and sort out the charging circuit. >> >> It would be easier if you had two identical batteries. >> >> --Bob A >> >> Ariel Rocholl wrote: >> > I would like to connect two batteries in parallel to service a RF >> > receiver. Both are Lipo batteries but battery A is high capacity and >> > main battery whereas battery B is reserve low capacity battery. >> > >> > The average consumption of the RF receiver is about 2A, battery A is >> > 5A/h and battery B is 1.5A/h. >> > >> > I do not see an easy way to: >> > >> > 1) have battery A depleted then (and only then) >> > 2) switch to battery B till it is depleted too. >> > >> > I would assume a large capacitor plus a very fast switching transistor >> > (IGBT?) may help to make it transparent to the load to a certain >> > extent. >> > >> > But perhaps anyone knows a better way to do this. Any help really >> > appreciated, I wouldn't like to reinvent the wheel but, except for low >> > current ICs in Maxim, I didn't find anything else doing this already. >> > >> > TIA >> > >> > >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > > -- > Ariel Rocholl > Madrid, Spain > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist