Wanting some advice on batteries, charging, etc.

[Cheeseburger]

Hi guys. I've just got back into RC and it's been about 20 years since I last really knew the ins and outs of the hobby. I bought a Neo Frog a couple of weeks back and i'm having an absolutely blast tearing it around the neighbourhood.

I've encountered a problem with my two-week old NiMH battery pack - it's dead. I'm not sure if it was a fault of the battery itself or if it was killed by a faulty charger ($30 Imax B3). Either way - I plugged into another battery pack at my local hobby store and the car instantly fired back into life, so I have a fault in the system that needs to be dealt with.

I took the el-cheapo charger back for a refund and now have a SkyRC B6AC+ V2 on the way. I'm just wondering, should I need to replace the battery what is the best type to go for with a Tamiya buggy? LiPo seems to be all the rage these days, but are they suited to Tamiya electronics? Do I have to run a particular type of battery with Tamiya gear.

And are there any basics I should know when using a modern charger? ie, how to get the most/best out of the battery?

I should mention I have plans to upgrade to a 17.5t brushless motor in a month or two (a christmas present to myself) - does this affect my battery decision?

[Butler]

If your going brushless it will likely be lipo safe, so go lipo for a battery.

Tamiya speed controllers don't have a lipo low voltage cut off, so its possible to over discharge the battery, which lipos don't like.

[Cheeseburger]

If it helps to know, I just brought a brushless on Ebay now. A 17.5t Tekin Redline. 2700 kV, 131 watts. That'll be the motor in this buggy until the end. Not exactly a menacing wind, but hopefully a little faster and cooler running than the stock 540.

BTW in regards to my faulty battery - is there a way I can isolate if this was caused by the charger, or a quality control issue of the battery itself?

[alfagta]

hi,

what current did you charge the battery at ? too high and you may have fried one or more of the cells in the pack , nimh is old tech and is far too unreliable , there are of course those who say its still perfectly viable , IMO we shouldnt have to be battery technicians to run rc cars back when i ran nimh i would buy 6 packs at a time knowing that at least 2 would fail quickly , if you are using the tamiya tble-02s esc then i suggest you go for LiFePO4 batteries which the esc has a safety cut for ,

i have been using them in my DT-03 neo frog and they have been perfect so far , not quite as much grunt as a li-po but more consistant than nimh or ni-cad and you can charge them quite hard , they make total sense for the tamiya owner who just blasts about for fun , check out zippy LiFePO4 2s packs at hobbyking , they are super cheap , you wont need a hard case pack in the dt-03 as it has a deep tub monocoque chassis .

have fun

[Cheeseburger]

I don't really know the detailed specs of that other charger. It was an Imax B3 - just a cheapo basic charger. I managed to get two full charges out of that battery pack and both times took around five hours to charge from flat (noted by LED indication).

The third time I went to charge I let it run to five hours but the LED indicator didn't register, so I gave it another half hour. Still no indication, so I gave it another half hour. And again and again. After an extra couple of hours charging time I realised something was up so I unplugged the pack. The battery was quite warm, but not hot.

The next morning I took it for a spin and only managed to run it out the driveway before it fell dead. Poked around with it for a while and tried to find a troubleshoot on google but nothing. A few hours later I tried again for a fix and it came back to life and I got a good 15 minute run in. Then once again it fell dead. It's not worked again since.

After all this I took it to the local hobby shop and the second they plugged in a fresh battery pack the car sprung back into life, so I know the problem is the battery... or the old charger I returned.

Yes, i'm using the Tamiya TBLE-02S. I'll check into the LiFePO4 batteries - hopefully I can track them down locally as postage from the US is a killer to Australia.

[alfagta]

I don't really know the detailed specs of that other charger. It was an Imax B3 - just a cheapo basic charger. I managed to get two full charges out of that battery pack and both times took around five hours to charge from flat (noted by LED indication).

The third time I went to charge I let it run to five hours but the LED indicator didn't register, so I gave it another half hour. Still no indication, so I gave it another half hour. And again and again. After an extra couple of hours charging time I realised something was up so I unplugged the pack. The battery was quite warm, but not hot.

The next morning I took it for a spin and only managed to run it out the driveway before it fell dead. Poked around with it for a while and tried to find a troubleshoot on google but nothing. A few hours later I tried again for a fix and it came back to life and I got a good 15 minute run in. Then once again it fell dead. It's not worked again since.

After all this I took it to the local hobby shop and the second they plugged in a fresh battery pack the car sprung back into life, so I know the problem is the battery... or the old charger I returned.

Yes, i'm using the Tamiya TBLE-02S. I'll check into the LiFePO4 batteries - hopefully I can track them down locally as postage from the US is a killer to Australia.

hobby king main warehouse is in HK so it should reach you in a few days

[Cheeseburger]

So i've been looking online for LiFePo4 battery packs... i'm not finding any with a decent mAh rating. Do they come in a 4000+ rating or are they all below 2000?

Perhaps I could make my own... if so, what cell size am I chasing?