R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 04-24-2003, 12:39 AM   #1
Tech Fanatic
 
Join Date: Nov 2002
Location: seattle, WA
Posts: 864
Exclamation Nimh Care questions (NEED HELP!!!!!!)

I just got two 3300 packs and one 3000 pack, they are my first NimH packs and I only have a slight idea how to care for them. I have a 16x3 pro2.5 charger. My first question is what voltage to charge them at? On the 3000 it says 5 amps and on the 3300's it says 6, but I heard the maximum you should charge Nimh packs was 5.5 amps, what do you guys reccomend? My next question is about storage/ discharging, should I store my packs with charge or should I store them discharged? My charger has a partial charge feature, should I use it? Another thing is that the mode three charge setting (Nimh coldstart) discharges the battary before it starts to charge it, why does it do that? It seemed to discharge the battary too much, I also waited like 10 minutes and it still didnt even switch to charge setting, so I just used the repeak charge setting (mode one, this is the one the the "quick start" instructions said to use for a fast charge) and it seemed to be fine. So basically this is what I've heard how to care for my new metal hydride packs:
Charge at a max amperage of 5.5 amps
Dump the pack on bulbs or in the car and then on a tray before recharging
Store the packs discharged

If I treated my packs like this all the time would they be fine and not lose any performance. Can someone give me a list of how they care for their Nimh packs like I just did above, also, any answers would be GREATLY appreciated. Even if you don't know for sure, any ideas that someone has I would like to know. Thanks a ton in advance !
racerdx6 is offline   Reply With Quote
Old 04-24-2003, 01:47 AM   #2
Tech Elite
 
Cole Trickle's Avatar
 
Join Date: Sep 2001
Location: Denmark / Europe
Posts: 2,571
Default

Check this
__________________
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250
Cole Trickle is offline   Reply With Quote
Old 04-24-2003, 04:36 AM   #3
Tech Elite
 
sosidge's Avatar
 
Join Date: Dec 2001
Location: Bristol, UK
Posts: 3,865
Default

My NiMH routine...

Charge rate - GP 3300's 4A, Sanyo 3000's 3A (you could go higher though, up to 6A for both, I charge at a low rate in the hope of longer cell life, certainly no shortage of punch or speed at these rates with the 3300's).

Delta/Fallback - 0.03v/30mV per 6-cell pack on GP 3300's, 0.06v/60mV on Sanyo 3000's.

Discharge - to 5.4v per pack after a days racing. I don't discharge between runs on the same day (no time).

Traying - NO. Some people like it, I definitely don't (bad experiences on cell lifespan), and the NiMH construction isn't designed for a deep discharge anyway.

Storage - Discharged to 5.4v. A part charge seems pointless to me, as NiMH's shed something like 10% of their energy per day, so they'll be discharged by the next meeting anyway.

There are as many different charging routines as there are racers, but obviously my way is the best...!
sosidge is offline   Reply With Quote
Old 04-24-2003, 05:48 AM   #4
Tech Regular
 
Join Date: Feb 2002
Posts: 292
Default

Do NOT store the pack discharged... always leave some charge in your Ni-MHs... at least 5.4V... but if you're not gonna use em for a few weeks, I would definitely do a partial charge...

I learnt it the hard way... you don't have to.

FYI, my 3000HVs became very unpunchy, lost runtime etc. when I let them sit for a month without charge
jwwu is offline   Reply With Quote
Old 04-24-2003, 04:04 PM   #5
Tech Fanatic
 
Join Date: Nov 2002
Location: seattle, WA
Posts: 864
Default

Ok, thanks a ton. Heres my new list :

Charge packs at a 5 amp to 6 amp charge rate
Leave packs partially to fully charged depending on when they will next be
used.
Discharge Nimh packs the day before I will use them.
Put them on a tray right before I charge them.
Cycle the packs to increase performance after a long storage.

Now I need to get a tray, which one should I get? Could a tray over discharge the battaries? I think the Trinity Real Time 2 tray takes the packs down to .5 volts per cell, 6 volts for the entire pack, is that too much? Does anyone here have any experiance with the Integy 16x3 pro2.5 charger? The instructions are very scarce which is very annoying, they should redo them and I have some questions. But I'm not gonna bother asking them if no one knows anything about the charger . Thanks again !
racerdx6 is offline   Reply With Quote
Old 04-25-2003, 09:05 AM   #6
Tech Elite
 
sosidge's Avatar
 
Join Date: Dec 2001
Location: Bristol, UK
Posts: 3,865
Default

Tray at your own risk, that's all I say.
sosidge is offline   Reply With Quote
Old 04-26-2003, 05:51 AM   #7
Tech Elite
 
Cole Trickle's Avatar
 
Join Date: Sep 2001
Location: Denmark / Europe
Posts: 2,571
Default

Problem with the Real Time 2, is it goes all the way down to 0 volts, unless you watch it. At my experience, then NiMh shows problems with false peaks, when equalized to 0,6 volt pr. cell.

Instead I would strongly recommend an equalizer like this:



The Robitronic discharges at approx 1 amp and cut off at 0,8 volt. It's budget friendly too.

Or Integys SP Saddle Relay Cut-off Discharger 5A, with selectable cut off. Integy equalizer
__________________
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250
Cole Trickle is offline   Reply With Quote
Old 04-26-2003, 10:21 AM   #8
Suspended
 
Join Date: Apr 2003
Posts: 403
Default

I need to getone of those trays.
R C king is offline   Reply With Quote
Old 04-26-2003, 10:27 AM   #9
Tech Elite
 
THeGame's Avatar
 
Join Date: Oct 2001
Posts: 3,012
Send a message via AIM to THeGame
Default racerdx6

you cant go wrong here. a good link that i live by

http://www.teamtrinity.com/tips/batts.asp
THeGame is offline   Reply With Quote
Old 04-26-2003, 07:06 PM   #10
Tech Apprentice
 
Join Date: Feb 2002
Posts: 57
Send a message via AIM to Torqer
Default

Here is my "routine":

NIght before, dump the batts on a bulb discharger with cutoff @5.4v
Let them cool for about 5 minutes and charge them @ 6 amps.
Repeak at the track @ 6 amps and race'em for the 5 min time and maybe 1 minute after.
Put them in battery case and leave em till next week then start at the top again. If by chance I dont use all my batteries(get there late cuz of work or something) I just leave them charged fully untill the next week.

I run Promatch GP3300's and this seems to be working great. My packs are about 2 months old and I can see no loss of performance to speak about. This is the way all of us do it at our track and some guys have had the same batteries for a very long time. I am not saying that this is "the" way to do it, its just seems to work for us.

Torq
Torqer is offline   Reply With Quote
Old 04-26-2003, 11:10 PM   #11
Tech Adept
 
Join Date: Sep 2001
Location: In Da Club
Posts: 215
Send a message via AIM to M Ignacio
Default

Torqer

Have you ever had to run a pack for a 2nd time on the same day? If so what did you do? How many volts do you set your delta/fallback?
M Ignacio is offline   Reply With Quote
Old 04-26-2003, 11:46 PM   #12
Tech Adept
 
warlord385's Avatar
 
Join Date: May 2002
Posts: 237
Default

how do you "cycle" nimh batteries. I have some gp3300 matched packs that only charge up to 2800mah voltage seems fine but runtime is horrible will cycleing help??????????/
warlord385 is offline   Reply With Quote
Old 04-27-2003, 02:12 AM   #13
Tech Apprentice
 
Join Date: Feb 2002
Posts: 57
Send a message via AIM to Torqer
Default

I have 6 packs so I have never had to run one twice a day yet. I have my threshold set to .03. I know someone who sometimes run theirs twice a day. They run em, discharge em, and charge them back up at 6 amps.

Warlord- sounds like you might have someother problems besides the batteries. You probably have something causing excessive drain on your cells. What car/motor/esc/gearing are you running? Make sure your drivetrain is free and not binding or dragging. Cycling NiMh cells are just like cycling any other cells. Charge/discharge/charge/discharge .
Torqer is offline   Reply With Quote
Old 04-27-2003, 01:58 PM   #14
Tech Adept
 
warlord385's Avatar
 
Join Date: May 2002
Posts: 237
Default

i don't things its the car/motor/esc/gearing. When i charge the bats thats the mah reading i get on the lrp pulsar competition. When i first got them in February they were fine then one day the all started reading at 2800mah on the charger. Is this normal for 3 month old batteries. I've checked the voltage across the cells and they are all nominal. ???????????????? batteries are so expensive
warlord385 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: Matched 3700 Nimh up to 4700 Nimh smarking1212 R/C Items: Wanted to Buy 5 04-16-2008 10:33 AM
spektrum z590 servo,4200 nimh,3800 nimh and duratrax piranha peak chager nikkon R/C Items: For Sale/Trade 9 02-11-2008 06:19 AM
Questions about NiMH/NiCD Batteries rcnewb2004 Electric On-Road 2 10-10-2007 01:11 AM
NiMH AA rechargables, 2300mAh!!! Questions donoman Electric On-Road 30 08-26-2004 12:52 PM
nimh battery care 70mph pan car Electric On-Road 1 10-09-2003 01:50 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 01:31 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net