NI-MH best charg rate

reptile · #1 02-26-2002, 07:51 PM

Hi i just got my first 3000 Batt can anyone help me out what is the best charge rate?

Moo-Shoe · #2 02-26-2002, 08:23 PM

A couple of questions before I answer your question. Are you racing or bashing? Are you running Panasonic SMH's, or Sanyo HV's?

If you're racing, you can see what I charge my cells at. If you're bashing, charge them at around 4.5 amps and you'll have loads of run time.

For racing, here's what I do:

Panasonic SMH
5 amp charge
5mv per cell
results in good run time, consistent output and fairly fast on the track.

Sany HV's
7 amp charge
7mv per cell
results in incredible punch, great run time, consistent output throughout the cycle.

I personally like the HV's better than the SMH's, but you'll get different opinions from different people you ask.

Also, I do dump my cells after each heat on a set of bulbs, and I'll tray them for about 5 minutes or so every once in a while just to equalize the cells.

Gutter Ball · #3 02-26-2002, 10:56 PM

I charged all my 3000's at 5amps on my Apex and Duratrax...but recently, I acquired an Integy 16X2 Pro v2.5 so I started charging them at 6.5amps...they get a bit warm, but I keep a fan on them. Might just be me, but my runtime seems to have improved (lots of power left after an 8 minute race).

reptile · #4 02-27-2002, 09:17 AM

Thanks For the input Guy's..

Hellonu · #5 02-27-2002, 09:31 AM

I Run SMC matched 3000hv cells. I normally charge them at 6amps as per SMC. They matched them at this rate so you can charge them at this rate. Danny has also tested with succes rates as high as 10 amps. IF im in a rush i have charged them as high as 8amps. They get hot but i have yet to suffer any problems with these new cells..

The voltage is so hight that i had to order an upgrade eprom for my Turbo35 so that i could cylce them properly

WHITESTER1 · #6 02-27-2002, 10:27 AM

Quote:

Originally posted by Hellonu
I Run SMC matched 3000hv cells. I normally charge them at 6amps as per SMC. They matched them at this rate so you can charge them at this rate. Danny has also tested with succes rates as high as 10 amps. IF im in a rush i have charged them as high as 8amps. They get hot but i have yet to suffer any problems with these new cells..

The voltage is so hight that i had to order an upgrade eprom for my Turbo35 so that i could cylce them properly

Actually if you ask Danny, he says the cells perform better when they are warm to hot. I charge at 7amps.

And NEVER put a fan on them WHILE charging. Heat is needed to create power.

Gutter Ball · #7 02-27-2002, 12:09 PM

Huh? Heat is needed to create power? I thought heat was BAD for your batteries?? So I should charge them without a fan, and THEN put them under a fan after they're charged??

WHITESTER1 · #8 02-27-2002, 12:21 PM

Correct! When I say "heat" I don't mean hot... just mildly warm. Do a test if you don't believe me. Charge the battery while a fan is blowing on it, then record the numbers. Discharge, then the following day, charge the same exact way. Record the numbers again. You will notice a better charge WITHOUT the fan.

If you goto www.rctech.net then go to "Company Forums" then to "SMC" Danny from SMC will answer any questions you have. That is where I read the info on NOT to put a fan on your batts while charging.

And with the 3000Hv's I get them warm to hot while charging. On my Millenium Pro, the threshold is set at 72Mv per pack. They get quite warm after a full charge at 7 amps. But they are SUPER punchy, and perform quite well. This was as per Danny's recommendations. Used strictly for racing purposes.

Fafnir · #9 02-27-2002, 12:27 PM

Overcharging is BAD for NiMH cells, the cells heat up when they are overcharging, overcharging and keeping a fan on the cells to keep them cool is still bad for the cells. No one wants to wreck a $90 pack. I charge my Sanyo 3000 NiMH at 4.5 amps on a peak detection charger set to .02 The discharging on a tray is a good idea to help equalize the cells, I wouldn't do it too often though. If you are a little careful the pack will last you a long time.

--Chad

WHITESTER1 · #10 02-27-2002, 12:34 PM

Quote:

Originally posted by Fafnir
Overcharging is BAD for NiMH cells, the cells heat up when they are overcharging, overcharging and keeping a fan on the cells to keep them cool is still bad for the cells. No one wants to wreck a $90 pack. I charge my Sanyo 3000 NiMH at 4.5 amps on a peak detection charger set to .02 The discharging on a tray is a good idea to help equalize the cells, I wouldn't do it too often though. If you are a little careful the pack will last you a long time.

--Chad

I don't know what cells you are talking about, but the 3000Hv's are very robust! They are simply the best cells I have ever owned. I don't know your expertise in this field Fafnir, but I trust EVERYTHING Danny from SMC says.
If you tray 3000Hv's you will gain voltage but LOSE runtime. If you just discharge to 5.4v runtime will not be effected.
If you don't believe me, like I said before, ask Danny yourself. I'm just not typing this to see my own words on the internet.. LMAO!!

Fafnir · #11 02-27-2002, 12:54 PM

Danny is by far the expert in the field, my experience does not compare with his. When I have put them in a tray I monitor the voltage of each cell and do not take any below 1V, all I am trying to do is make sure that when charging I do not end up overcharging any of the cells. I am just really careful as I want the 3 packs I bought to last a long time. Do the math, it is around $270 I spent on batteries alone.

--Chad

Hellonu · #12 02-27-2002, 10:45 PM

Danny is the man.

Whistler you are right about the heat. not hot.

Another thing Danny suggest is to run backs twice a day. When we went to Cleavland this past November he gave his team drivers a pack each and they ran if for the entire weekend. They ended up winning the stock touring and 1/12th scale titles!

FAFNIR: As for the volt threshold. the .02 setting is what you do for panosonics since they are so delicate. but the sanyo HV cells use a .07 cut off. just like alkaline 2400s use

Fafnir · #13 02-28-2002, 10:33 AM

I have found that if I set it above .02 the packs get really hot in a hurry. I really don't want to wreck a $90 pack. We are talking about the Sanyo 3000 NiMH right???

--Chad

Mongoose420 · #14 02-28-2002, 06:06 PM

If your talking about the older sanyo's then your doin it right. There quite finiky like the smh cells. the sanyo 3000Hv's like to be charged "more" like nicads but do not deep cycle them with the discharge tray. I charge mine at 6.5 amps and only discharge em at the end of the race day with a set of bulbs then a real time 2 tray. they get slightly warm about like nicads but i dont discharge em between heats. I only tray my cells once a week and store them fully charged between racedays. I feel this will give me a good mix between voltage and my run time will not fall off so fast.

micro_man · #15 02-28-2002, 06:40 PM

i got a few q's?

how come on my duratrax intella peak is says you should charge nimh at 3 amps?

do you need to discharge nimh as you do with nicd?

i am wondering becasue i just ordered 4 3000 packs so i dont want to ruin them...they are a lot of mulla!

thanks,
Kurt

Hellonu · #16 03-01-2002, 08:42 AM

If you want more details got to www.smc-racing.com for more batt maint..

But to clarify:

Sanyo 3000H (original nihms)
charge rate 5amps
peak cut off 0.07
dishcarge 30amps

Sanyo 3000HV THESE ARE THE NEW CELLS
charge rate 6amps
peak cut off 0.07
discharge 30apms
equilizer tray is optional.

As for the rest of nihms i would not at this stage of the game be guying them. If your looking for great voltage with less headaches the 3000HV from SANYO is the cell to get