bdtracing

Ok kinda mad [:@] I bought a charger off eBay. Pro-Max Black Widow AC/DC Peak Charger When I bought this charger I was under the impression that it would also charge NIMH. But after taking to a friend he said they made 2 different versions of that charger. They look exactly the same the only difference is that one will charge NIMH and one will not. The only way to tell the difference is, if it says at the top AC/DC CHARGER it is only for nicd, And on the newer version they say AC/DC Ni-cd and Ni-Mh batteries. Of course I am the unfortunate one who bought the wrong one. [&o] I also just bought a brand new set of Sanyo NiMh 3000 7.2 Volt Packs for my emaxx. I don’t know if there is any truth to this, or if there is something that I can do to make this charger work. I don’t have any more cash in my RC budget. So any help is appreciated.

rmenke

My Feedback: (13)

Sell it to someone who can use the ni-cad application and they buy a real charger recommended by someone in the know. Battery manufacturers like SR Batteries know their stuff and would and do recommend chargers. A good all around charger that will do it all including lead acid is the GP Trinitron. You may ask someone like Red Scoefield(not sure of spelling) that helps on RCM forums about how you can use the thing on a timmer, but he is going to also tell you to get a good peak charger, otherwise you will be killing batteries frequently. I have purchased a lot of good stuff on ebay, but always research the item if I dont know it first hand. Wish you luck!

bdtracing

Thanks for the advice. I thought I was getting a good peak charger but now I see I was in error. [&o] Oh well i just wont be able to race my truck this weekend. I am sure its a good peak charger but just not for nimh.

guver

My Feedback: (325)

If you do some checking you may find that it is the exact same charger , just relabeled. I don't know of course because I haven't researched it.

bdtracing

Thats just it there is not much out there on this charger. And I for sure do not want to fry my batts

guver

My Feedback: (325)

I see you are right, there really isn't much info out there. I did a little research and can only find one version. I think I found the manufacturuer, but there's virtually no info.

Do you happen to have a link to a owners manuel?

chances are good that they made a nicad charger to begin with if they are that old and then when nimh came around they either updated or did nothing and relabled.

bdtracing

No man, I have looked all over the place for something. All I can find is the link to the new charger that they make. at the bottom of that owners manual it says for service and information withing the USA go to http://globalservices.globalhobby.com but nothing there either

bdtracing

It must be a piece of junk anyway if nobody has heard of it and its no were on the internet. Well I just bought a DuraTrax IntelliPeak DC Only Deluxe Pulse Charger that i know will work. So if you know anyone who wants to buy a Nicd peak charger. My name is modchipman67 on ebay and it will be for sale tomorrow

xkwizt

I use a NiCd charger to charge my NiMh, it will not harm the batteries in anyway EXCPET NiCd chargers cant detect wen a NiMh battery is full so it keeps charging it and over charges it to infinity, so if u have a 3000mah battery and its a 3amp charger, put the battery on for 1 hour and take it off, thats how i do it and my batteries are fine, they never get worse, actually i think der getting better LOL, my car runs longer than usual sometimes. all about maths, so if u have 1000mah battery with 3 amp charger, thats 20 mins of charging

Mad Wax

xkwizt but how do you know of the current charge rate? If the pack has ????mah and you want to top up the NIMH pack how long would you leave it on? You need a delta peak to stop the charge once it's detected it's charged.

JNorton

My Feedback: (2)

xkwizt,
Then of course the battery is toast but hey it's okay as it is only money. [&o][&o] Kinda like using an industrial heat gun for shrinking monokote. Use it really - really quick at it won't burn holes in the covering. Isn't it better to just spend the money for the right tool?

John

guver

My Feedback: (325)

I would say that a peak nicad charger will slightly harm batts everytime it is charged. It will slightly overcharge nimh batts and kick off just like normal.

JNorton

My Feedback: (2)

Guver,
I think we agree that the normal peak sensitivity or threshold on a Delta Peak charger for NiCd is 10 mV and the peak sensitivity for NiMh cells is 5 mV. This is the voltage drop after the cell heats and becomes charged. I believe you are thinking that the difference is only 5 mV so the NiMh cell would only become slightly overcharged.

I have been looking for charging graphs that show the peak clearly and I can't find any! Anybody else want to chime in?

John

EDIT-> Found a Sanyo 2500 mAh NiMh graph.

JNorton

My Feedback: (2)

Red or Rodney,
So are we to deduce from the above that a Delta-Peak charger for NiCds can sucessfully charge NiMh cell? What am I missing? I could swear that I've heard of fellow club members frying NiMh cells before they purchased the proper charger but now looking at the graphs I'm confused.
John

JNorton

My Feedback: (2)

One thing I do know is that NiMh packs heat up really quickly once they are charged- quicker than NiCd. Which is the reason for the lower threshold voltage in the first place. It would seem to me that you would experience some loss in pack life. If the packs get hot I would not continue using a NiCd charger.

guver

My Feedback: (325)

I can produce some graphs and view them, once I charged a set of nimh AA and the drop was well over 200 mv for 8 cells. I was testing a charger and kept a watch on the temps. The cells seemed normal temp (110) at around the "full" mark of 25-40 mv and continued on past 140 deg F when it finally shut off. This particular charger was one of those nicad/nimh chargers.

Here's a interesting question, who says the cell is full at 10 mv or 5 mv drop? How would one tell? discharge it?

JNorton

My Feedback: (2)

Guver,
I guess we must trust the cell manufactures data. They are the ones with the test data after examining thousands of cells for longevity and life. I guess we could reverse the question and ask of the reputable charger manufacture which one don't use 10 mv or 5 mv drop as their defaults?

As far as how one would tell. One of the indications must be the temperature of the pack as well as monitoring voltage and current. The manufactures graphs are also temperature dependent. Usage depends upon length of discharge, type of discharge - pulse - continuous so many variables you could spend a life time like Red has.

John

xkwizt

my nicad charger is only 60mah lol, it cost me 10 bucks, i just leave it overnight to get 480 mah into my 2400 cells, so i doubt it will do anydamage, and yes i am investing 175 dollars in a nimh/nicd/li-ion charger that can auto detect each and charge each to 100% with no overcharing, and its AC/DC with a charge rate of 5.5amps/5500mah and 2-20amp discharge rate no its not crap, its original price is $280 but im getting it from overseas. ps. i quote all prices in aussie dollars, so times it by 0.75 to get american dollars