Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Marine Electronics Forum
Reload this Page >

Rechargable battery pack rebuild - HELP!

Notices

Rechargable battery pack rebuild - HELP!

Old 02-05-2003, 06:05 PM
  #1  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Nov 2002
Location: Menominee Mi.
Posts: 168
Default Rechargable battery pack rebuild - HELP!

I would like to rebuild a couple of battery packs for an old Apelco 501 handheld marine radio. The cases snap right open. Inside are 9 Ni-cads, 1.2 volts each, wired in series for a 10.8 volt total. They are 2/3A solder-tabs, 600 mAh.
What I'm wondering is, instead of Ni-cads, could I use lithium? In the same space I could fit 3 litium batteries 3.6 volts each with much higher mAh ratings.
Also will I be able to use the same charger? It is just a 110 A.C. to 12v D.C. converter 200 ma.
Lithium seems to be the way to go to me, or am I missing something?

Thanks, Mike
3to1 is offline  
Old 02-05-2003, 07:36 PM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Aug 2001
Location: Raleigh & Holden Beach NC
Posts: 2,024
Default Rechargable battery pack rebuild - HELP!

so changing battery type is OK. And your charger should be fine as well, just will take a bit longer to fully charge since you're recharging more Ahr.
Preoccupation is offline  
Old 02-05-2003, 07:49 PM
  #3  
Junior MemberCaptains Club Member
 
Join Date: Sep 2002
Location: Dublin, CA
Posts: 20
Default Rechargable battery pack rebuild - HELP!

Here's a pretty good link: Batteries-101

This link says different types have different charging characteristics: http://www.ebatts.com/batterytips.asp#5a

---Steve
Your Helpful Daemon
SteveE is offline  
Old 02-06-2003, 06:37 AM
  #4  
Senior MemberCaptains Club Member
 
Join Date: Aug 2001
Location: Raleigh & Holden Beach NC
Posts: 2,024
Default Rechargable battery pack rebuild - HELP!

wasn't thinking deep thoughts about chemistry when I responded. Typicallly, NiCad chargers do a full discharge before charging, or have some way to initiate a "conditioning" charge. Lithiums can't handle this routine. So if your charger isn't adaptable, this may be the deal breaker. I tried to find an instruction manual for your radio to check the charging routing, but couldn't find one. Sorry for the goof.
Preoccupation is offline  
Old 02-06-2003, 06:55 AM
  #5  
Senior MemberCaptains Club Member
 
Join Date: Feb 2001
Location: West Virginia
Posts: 3,877
Default Rechargable battery pack rebuild - HELP!

Preoccupation,

If my memory serves me correctly those old Raytheon radios plugged the charger directly into the battery pack, and in fact you could charge them without the battery on the radio. So, if I havne't lost to much gray matter then the answer is that there isn't any charging circutry within the radio itself.

Thom

"For every complex question, there's a simple answer. And it's wrong."
(--H. L. Mencken)
Thom is offline  
Old 02-06-2003, 08:04 PM
  #6  
Senior MemberCaptains Club Member
 
Join Date: Aug 2001
Location: Raleigh & Holden Beach NC
Posts: 2,024
Default Rechargable battery pack rebuild - HELP!

Since it is "old" the charger is probably just a simple constant current charger with a voltage sensor to shut it off. Very unlikely it's not the constant current/constant voltage routine the lithiums need.
Preoccupation is offline  
Old 02-07-2003, 05:58 AM
  #7  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Nov 2002
Location: Menominee Mi.
Posts: 168
Default Rechargable battery pack rebuild - HELP!

Yes, the charger hooks directly to the battery, and it is just a constant 12volt. Inside the case there is a diode and what looks like a heat sensor wired in. After looking at the links provided I see that not all lithium batteries are rechargable, so the ones I thought I could get a good deal on may not work anyway. Thanks for the help.
Mike
3to1 is offline  
Old 02-07-2003, 06:18 AM
  #8  
Senior MemberCaptains Club Member
 
Join Date: Aug 2001
Location: Raleigh & Holden Beach NC
Posts: 2,024
Default Rechargable battery pack rebuild - HELP!

NiCad chargers use either a voltage sensor (to look for a voltage drop) or a thermal sensor (to look for heat rise) to turn off the charger. Looks like you're out of luck here 3to1.
Preoccupation is offline  
Old 02-09-2003, 12:01 AM
  #9  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Nov 2002
Location: Menominee Mi.
Posts: 168
Default Rechargable battery pack rebuild - HELP!

So what your saying is lithium-ions need full and constant voltage for charging? If thats the case I could simply remove the heat sensor from the battery pack.The charger is just a 12v. power source.
3to1 is offline  
Old 02-10-2003, 07:14 AM
  #10  
Senior MemberCaptains Club Member
 
Join Date: Aug 2001
Location: Raleigh & Holden Beach NC
Posts: 2,024
Default Rechargable battery pack rebuild - HELP!

need a constant current charge to recharge them up to a certain voltage. Then the current gets cut back and a constant voltage is applied to finish the charge. A NiCad charger has a trickle current charge that won't work on Li-ions.
Preoccupation is offline  
Old 02-11-2003, 05:26 AM
  #11  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Nov 2002
Location: Menominee Mi.
Posts: 168
Default Rechargable battery pack rebuild - HELP!

Thanks for straightening me out!
3to1 is offline  
Old 02-11-2003, 06:06 AM
  #12  
Senior MemberCaptains Club Member
 
Join Date: Aug 2001
Location: Raleigh & Holden Beach NC
Posts: 2,024
Default Rechargable battery pack rebuild - HELP!

batteries are a pain in the a$$ and the different chemistries and charging needs can be confusing. But for now they're the most economical way to store energy so we'll have to deal with them for some time to come.
Preoccupation is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread