battery packs

[Badillac]

Okay, so I'm looking at my battery pack here, the first pack I've bought in like 15-20 years, and I'm thinking about what the guy in the hobby shop was trying to tell me. I can't remember what he was saying about older batteries vs. Nimh batteries, all I know is he was trying to sell me a $75 battery for a $63 car. So I bought an el-cheapo $11.99 Trinity Patriot 1500 mah 7.2V. Hey, it was twelve bucks, what do ya want from me? I charge it, it works, but doesn't seem to last very long (I haven't timed it, but less than 13 minutes I imagine).
Can someone explain to me (in english), cuz I am relatively new to this, (and electrically unschooled) the meaning and benefits of Nimh battery numbers. I read in a magazine that I should go with a battery that's 4200 or higher, but I don't know what that means. Sure I can go buy a pack that is exactly what the magazine says, but I'd like to know why I'm doing it. And what of voltage. I'm leary of putting newer technology higher voltage stuff in my RC10 that has a motor/speed controller/reciever from 1984. What are the do's and don'ts with mixing older tech electrics with new tech power?
Thanks.

[aconsola]

The publications and the shops push the 4200+ batteries since that is what makes money. How much profit can there be in a $12 stick pack?
The latest and greatest cells will provide better voltage under use. Both the $75 and $12 battery should have roughly the same voltage at rest. The expensive one will maintain that voltage better When a load is placed on it. The cheaper packs drop their voltage down quite a bit when under a load such as accelerating from a stop. This gives less power.

The 4200 refers to the capacity of the pack, how much charge is in it. This determines how long the car will run. The 4200 will have almost 3 times the runtime of a 1500, but this comes at 6 times the cost.
If the speed of the car is adequate for you with the 1500 you are better off getting a couple packs to change out to get more run-time.

Running the 4200 in a vintage car with old electronics could be a problem for a number of reasons including just getting the fatter cells into the car. The long runtimes without any cooling periods could cause overheating of the esc/motor.

[Tadracket]

If you are getting 13 minutes on a 1500, buy a few more of those. I don't guess I ever got more than 8-10 minutes on a pack. I usually run low turn motors. That will cut in to the run time but boy does it add to the fun time.

[MOmo]

I wouldn't worry. As for run times, that sounds about right. Like Tad said, a 1500 will usually only net about 10-15 min of run. Also, because its new, it might take a few cycles to build up a decent amount of charge.

Batteries are tough these days. I know that when I was racing, the 3000s and 3300s were the ones to have. now we've got Lipo and 4200s. I compete in a vintage class at my local track and I am using some old 2400s. it last me the race and then some. I don't need a ton of power, and it gets me around the track fairly quickly.

I've been debating on going Lipo, but im still undecided. Esp. since i just picked up a 4wd.

For playing, if you can still find them, id say 1500 to 2400 should suit your "playing" needs.



MOmo

[Tadracket]

I picked up 3 Tower batteries for something like $9 a piece. Not the greatest but I am only bashing. And I live in a not so exciting place to run buggies so once I am done running 3 packs, I am ready to move on to something else.

[Halgar]

I wouldn't worry. As for run times, that sounds about right. Like Tad said, a 1500 will usually only net about 10-15 min of run. Also, because its new, it might take a few cycles to build up a decent amount of charge.

I agree.

I run 1500 NiCads in my clods, which have two motors and four wheel drive. With stock Mabuchi 540 motors and a Tekin Titan ESC I can get 10-15 minutes. These are old batteries that have been abused, and I can still get nearly what I got out of them when they were new.

Also, think of mah rating as bucket size. The bigger the bucket, the more you can carry, same with mah, the bigger the mah rating, the more storage capacity it has and the longer it will last.

[Badillac]

Awesome, thanks for the insight.

[justinspeed79]

Radio Shack sells a 6 cell stick pack made with GP3300 NIMH cells for $25. They are great batteries for bashing around with, and will give increased performance and twice the run time of the 1500's you're using now. I highly recommend them if you are looking for a good cheap battery pack. I have a couple that have been very well used for over a year now and they still work great.

[RC Chick]

Radio Shack sells a 6 cell stick pack made with GP3300 NIMH cells for $25. They are great batteries for bashing around with, and will give increased performance and twice the run time of the 1500's you're using now. I highly recommend them if you are looking for a good cheap battery pack. I have a couple that have been very well used for over a year now and they still work great.

ahhh they went down, thanks I need some new ones. My darn charger took a crap and blew up a battery I was very mad, I just got it and only used it once. Oh well I got a new charger now

[Halgar]

ahhh they went down, thanks I need some new ones. My darn charger took a crap and blew up a battery I was very mad, I just got it and only used it once. Oh well I got a new charger now

Which brings up another good point about changing battery type. Not all chargers are created equal. Each type of battery (e.g. NiCad, NiHm, Lipo, etc ) requires different charging characteristics and peak sensing requirements. A 10 or 15 year old charger certainly won't have the peak sensing requirements, and likely won't meet the charge needs of the battery either.

[purpletimbo]

If you want cheap and effective, I chanced a pair of 3800 nimhs from china, with 2 slow chargers and post to the UK they worked out around $25 all in, I have a pair of $80 a piece 4300 nimhs in my Emaxx, and they give probably within 90% run time equivalences. Excellent batteries for the money, and unlike the 4300s, which were a tight squeeze in some cars, they fit my Tamiya TT-01 etc perfectly.
Cheers Tim
On ebay all the time under 3800 nimh

[RC Chick]

someone told me that battery packs can be re-conditioned. Is this ture and how is it done?? I see batteries all the time on ebay but really how do you know they aren't crap? If you get one and they are then are you out the money or what?

[Eau Rouge]

Radio Shack sells a 6 cell stick pack made with GP3300 NIMH cells for $25. They are great batteries for bashing around with, and will give increased performance and twice the run time of the 1500's you're using now. I highly recommend them if you are looking for a good cheap battery pack. I have a couple that have been very well used for over a year now and they still work great.

I would second that suggestion. Those GP 3300s and 3700s were and still are some of the most durable NiMh cells ever made for R/C cars. I still have a few 3700 packs that I use for practice, and they continue to take a beating 5 and 6 years after their prime. The price at Radio Shack makes them a no-brainer, and for a quality cell, you can't really go wrong with those.

Also, be sure that you are charging your NiMh with a charger intended for NiMh cells. NiCd cells are ancient technology and require different charging techniques from NiMh cells.

someone told me that battery packs can be re-conditioned. Is this ture and how is it done?? I see batteries all the time on ebay but really how do you know they aren't crap? If you get one and they are then are you out the money or what?

No, they cannot be reconditioned. Once they have used up their practical capacity or have been damaged in any way, they are landfill. Don't buy any battery that has been claimed "refurbed" or "reconditioned".

Used batteries should be cheap or free. At least nowhere close to new prices.



doug

[knucklebuster]

Badillac, I contemplated nimh batteries too. When I got back into rc's I bought some cheap 1500nicd batteries for my old Tekin chargers. At the time nimh batteries costs more than the RC10s I was buying! I decided to try nimh and the difference was night and day. The Tekins charge nimh with no problems i.e. explosions. I don't know if I am getting the battery's full potential, but the performance is very good IMO.