phil@diablo.amd.com (12/20/89)
There's an article on fast chargers in EDN, 12/7/89.
It has a nice graph of three parameters, voltage, temperature, and
pressure as the battery approaches overcharge. It looks like
temperature is a useful charge indication and that pressure starts to
climb at the 80% level. This is important because if the battery isn't
made to handle the pressure between 80 and 100%, it will vent and lose
electrolyte.
But the best indication is negative delta voltage. NiCds will drop in
voltage right when they reach 100%. They show a simple looking circuit
but caution that it really isn't that simple.
Lead-acids seem more difficult and variable and no general solution
for fast charging is offered, but they do say the most common charging
(as opposed to fast charge) is constant-voltage.
Finally, they have an express request system for info from the
manufacturers. It sounds great!
--
Phil Ngai, phil@diablo.amd.com {uunet,decwrl,ucbvax}!amdcad!phil
Ann Landers says "Let's talk about legalizing drugs."mikemc@mustang.ncr-fc.FtCollins.NCR.com (Mike McManus) (12/21/89)
In article <28472@amdcad.AMD.COM> phil@diablo.amd.com writes: > > Lead-acids seem more difficult and variable and no general solution > for fast charging is offered, but they do say the most common charging > (as opposed to fast charge) is constant-voltage. Question: Are the so-called "gel-cells" the same as lead-acid batteries? I have several gel-cells that I picked up cheap at a suplus store several years ago. I'm wondering what the effects of leaving them uncharged for long periods of time are. I don't have an immediate project in, but figured I would come up with something eventually (OK, I admit it, I'm a pack-rat and that was all just a rationalization! But don't tell my wife that... :-). Should I occasionally discharge and charge the cells to keep them in proper working order? -- Disclaimer: All spelling and/or grammer in this document are guaranteed to be correct; any exseptions is the is wurk uv intter-net deemuns. Mike McManus (mikemc@ncr-fc.FtCollins.ncr.com) NCR Microelectronics 2001 Danfield Ct. mikemc@ncr-fc@ncr-sd.sandiego.ncr.com, or Ft. Collins, Colorado mikemc@ncr-fc@ccncsu.colostate.edu (303) 223-5100 Ext. 360 (they're ugly, but they work!)
phil@diablo.amd.com (Phil Ngai) (12/21/89)
In article <MIKEMC.89Dec20104252@mustang.ncr-fc.FtCollins.NCR.com> mikemc@mustang.ncr-fc.FtCollins.NCR.com (Mike McManus) writes: |Question: Are the so-called "gel-cells" the same as lead-acid batteries? I I think gel-cells are lead-acid chemistry. |ago. I'm wondering what the effects of leaving them uncharged for long periods |of time are. I don't have an immediate project in, but figured I would come up I wouldn't leave them uncharged for ANY period of time. |Should I occasionally |discharge and charge the cells to keep them in proper working order? I don't think they have NiCd memory so you probably don't need to do this. If I am wrong I hope that someone will correct me. -- Phil Ngai, phil@diablo.amd.com {uunet,decwrl,ucbvax}!amdcad!phil Ann Landers says "Let's talk about legalizing drugs."