phiberoptik

Probably an age old question within the electric RC world. NiCd vs. NiMH

I am a novice RC fan with little indepth knowledge of the RC world. I simply want to parking lot bash with my 1/10th and maybe move on to Off Road RC but staying within Electric for the simplicity of it. I like high speed and with having multiple packs, Im not too concerned about run time as I can switch them out. I never plan to officially race any of my RCs.

I currently have several NiCD packs and a Pirahna Quick Charger for them and thats great for the parking lot.

Would I benefit substantially by moving on to NiMH and buying a charger for them? What are the benefits and would it be worth the money for my situation?

running_gag

It is not an age old question anymore. Nimh are easier to maintain, give more punch per pack, longer run times, and just have a longer usefull life. a lot of us are deciding if we can afford to go to lipo.

guver

My Feedback: (325)

I think if you have good quality 2400's and compared to generic 3000 nimh it would be a mistake, but if you happen to have cheap 1500's and are comparing to 3300-4300's thn yes it would be worth it.

phiberoptik

yeah... lipo is for another day hahaha. I dont think I want to get into all that quite yet. Let me get bored with brushed motors and NiCD/NiMH before I mess with brushless systems and lipo.

thanks guys

raz54

NiMh are far better than nicads. They don't develop a memory like nicads so you don't have to discharge them all the time before charging. If you get a good NiMh you'll will see the difference in how fast you car goes over the nicad.

phiberoptik

Ok, well i have this charger...

http://www2.towerhobbies.com/cgi-bin...&I=LXSG85&P=ML

will this work with NiMH battery packs? Nothing listed mentions them.

Thank you.

running_gag

It'll work, but timed chargers are evil. EVIIIIIIIIILLLLLLLLLLLLL1

phiberoptik

can you elaborate on why they are evil?

also, how can I guess how long i need to leave it on the charger?

running_gag

That is why they are evil. with a timed charger you will either undercharge the pack or overcharge it. undercharging limits your speed and runtime, over charging limits your overall battery life. you can pick up a decent peak charger for about 30 to 50 bucks. if you would rather not buy a new charger estimate it this way. take the mah rating of your battery (ie 3000) then devide it buy your chargers charge rate (ie 3 amps. 3000/3=1000) devide the answer by 1000 (1000/1=1) that is how may hours it will take for your charger to charge a completly dead battery. where it gets complicated is that a battery is never compleatly dead.I would discharge the battery in tha car till it is barely moving and then only charge it for 3/4 of the time you came up with.

Yub, yub, cmdr!

But it is a very accurate estimate for a decently discharged battery because the ACTUAL charge rate is less than the theoretical charge rate, and so it balances out.

mattnin

Timed chargers are horrible. If you aren't detecting a peak, how can you be sure that your packs are ever fully charged, therefore not using a packs full potential.

For instance, I use IB 3800 batteries, but routinely charge them past 4500mah before peaking using an ICE charger. So basically, I have 4500mah packs, but your timed charger would never know that.

Yub Yub, what do you mean that the actual charge rate is less than the theoretical charge rate? This makes no sense to me because at 1C, my IB 3800 should be charged at 3.8A but I charge them at 6.5A all the time.

running_gag

now that I didn't know. most important thing is check your batteries while they are charging. warm is good, hot is bad.

cjg

If you have a timed charger, stick with NICD, they are far less susceptible to damage from overcharging than NIMH. Most of them clearly state they are only for NICD, that is no lie...

d16z6

What I would recommend is use an average charge rate of 2.5A or so in your calculations (I think that's the specs for those chargers). Then I'd charge about 80% of the required time for a dead battery pack. Then I'd charge towards 100 but monitoring every now and then with an IR thermometer. You can get away by doing that. I think for NiMH you want to unplug it when you are seeing temperatures before 120 because you don't want to go over 120/130 F.