Notices
Ask the Expert Sal - Electric Airplane Advice Here is your chance to ASK SAL, the expert for all your electric flight related questions. If you are not Sal, please do not answer questions in this forum.

Charger questions?

Old 05-01-2007, 07:35 AM
  #1  
Senior Member
Thread Starter
 
Join Date: Dec 2003
Location: detroit, ME,
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Default Charger questions?


I have a few questions regarding a Multiplex charger I just purchased.
I will start with the receiver battery. These are Nicads.
1. I have only fully charged these batteries once with the Futaba supplied charger for about 15 hours. I assume to cycle these packs my cycle should be discharge then charge? D->C on the menu?
2. Most sites say cycle three times for NiMH and at least once for Nicads. Should I cycle more than once to format these?
3. I have a 600 mAh battery and the pack says slow charge is 60 mAh. The Multiplex charger only goes to .1 amp. I assume this is 100 mAh? This is over the recommendation but will this be ok for a formation charge and a slow charge in the future?
4. These batteries do not have a discharge rate. Should I use .3 as a discharge rate?
5. My receiver pack is four cells so I assume my cut off voltage should be 4.0 volts?
6. After I cycle my batteries and use them I assume most of the time I just want to charge them and not cycle them. It appears cycling should be done a couple of times a year to check your batteries. So how do I just charge my batteries? Can you disable the cycle mode so it will just charge the batteries and turn off?

Old 05-04-2007, 03:37 PM
  #2  
Senior Member
 
Join Date: Aug 2002
Location: Williston, VT,
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Charger questions?

I don't like to cycle batteries...for any reason except to cycle NiMhd's at the beginning or thier life. Nicads do not need them as the modern batteries do not develop memory so no need to cycle. If you have to cycle a battery to bring it back up to a good charge you are better off throwing it away and getting a new battery. This is much safer for the more costly aircraft!
To really properly discharge a battery you would need to discharge individual cells. When you dishcarge or charge a battery you are averaging over all of the cells and some may be at higher voltages then others. The low voltage cells could dishcarge too low dmaging that cell.

I fast charge all may batteries, but once in awhile (every 6-10 charges) I will slow charge the abttery. This will allow the cells to top up and even out.

In answer to your questions:
1. Yes, that sounds correct
2. 100 ma for a slow charge is fine. You can fast charge a NiMhd at 1C and if it's a good battery at 2C. You can charge a Nicad at 3C I will assume you have a Multiplex charge with autopeak capabilities.
3. This is OK. You need to run charge?discharge NiMhd's 3-4 times to get to full capacity. Nicads need really none of this
4. A 300 ma discharge rate of a good 600 mah battery is OK but would consider a 1 hour discharge rate at first.
5. Nope ... 4.4 volts, this makes for an AVERAGE of 1.1 volt per cell
6. Don't cycle...slow charge The charger should have a normal charge mode. What charger do you have?


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 Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.