Durga first run
 

Hey

So I took my Durga to a local BMX track for a run today. It's fitted with an LRP 12x2 motor, and a 7.2v 4500mah battery pack. It had been charged at 4amps on a peak prediction charger (or whatever the proper name for such a charger is anyway).

Anywho, it seemed to run fine, but the battery only lasted 4-5 minutes at most. Is this to be expected until the car settles/beds in, and the battery has been charged a few times?

Is there a recommended pattern for what setting to charge the battery on?

Also, I did have an upside down landing moment, which split/bent the front graphite shock tower. Are they generally regarded as a consumable to all intents and purposes?

I did seem to have intermittent connection issues as well, so that is another issue I need to look at, possibly caused by water getting under the body shell.

Any input and pearls of wisdom from those more knowledgeable than myself (not difficult!) would be hugely appreciated.

Cheers!

what connectors are you using?
You should get anywhere from 7-8 minutes to about 20minutes from that battery/motor combo, depending on use. Playing on a BMX track I'd guess would be on the high end of things. If you're only getting 4-5mins then that doesn't sound right.
For messing about I'd keep the plastic towers on tbh - the Carbon ones might(?) be stronger in some cases, or stiffer, but a nasty knock can still damage them. I bought 4 front towers for my 501X to give you an idea.
I have crashed the Durga in such a way that would probably have cracked a carbon tower - but I'm racing with all the plastic parts on there still and it's been fine.

What charger did you use?

Yeah ok, so something is wonky then!

The plastic towers will be back on tonight when I clean the car for sure.

Lemme give you a list of the bits, and see what you think.

Charger is this:
http://www.modelsport.co.uk/?CallFun...n&ItemID=23075

Battery is this:
http://www.modelsport.co.uk/?CallFun...n&ItemID=29035

Motor is this:
http://www.modelsport.co.uk/?CallFun...n&ItemID=24588

ESC is this:
http://www.modelsport.co.uk/?CallFun...n&ItemID=18553

All controlled by a Hitec Aggressor CRX radio setup.

I don't know how big an influence the slipper clutch will have on battery life, as I can't honestly know if it is set right or not.

Thanks for the help!

Well I can tell you the connectors on that battery absolutely cannot handle anything as fast as a 12 turn motor - not even close!
If they aren't very hot and losing lots of power - then they are already terminally melted and fused together! :lol: Just remember to take some scissors with you and cut one lead at a time! :thumbsup:
If you want similar function then DEANS style connectors are the best option - they work in a similar way and won't melt.

I've no idea what the cells are tbh, if you want stick sport packs like this it's best to get some brand name cells you can recognise as these could be anything. The cells (and of course the connector) are probably the culprits.

The charger - not sure tbh. You're best with even a cheap 2nd hand charger off here over the one you showed - maybe it's OK but it just doesn't look like it has all the settings you might require (low cutoff for the nimh for example) but if the cells aren't getting too hot whilst charging then it should be OK - unless it's false peaking and the cells are still cold / hence your run time???

Well when the pack is on charge, and it starts bleeping to say it has peaked, the cells are warm, but nothing like hot, they are just warm to touch.

The battery connector didn't melt, as i unplugged it without problem, and I don't recall it actually feeling hot either.

Are these the deans connectors you mean? (and matching sockets)
http://www.modelsport.co.uk/index.ph...n&ItemID=11418

At this stage while I am getting acquainted again with RC cars, and getting practice so as to be good enough to entertain the notion of club racing, my budget is a little restricted.

All that said, my mate was chucking his hotshot around for 10+ minutes with the same battery pack as I have, and the same charger. He has a different motor and ESC though, so I know it must be something to do with my car setup logically.

One thing I did wonder is how best to 'waterproof' the motor connectes, as quite a bit of water ended up splashed around, which I don't think helped my cause much.

I have much to learn!

Cheers!

New, budget cells will false peak and perform poorly for the first few charges, but that charger is not really suitable for NiMh's, despite what the marketing bods will try and tell you.

If the cells are not warm to the touch after charging from cold (never charge a hot pack) that is a good indicator that they have false peaked. Just hit the charge button again, but keep an eye on the cell temp.

As Jimmy has said, the Tamiya connector is utter bobbins and you would be far better off with a Deans style plug as they are polarity protected and thus user (idiot :woot:) proof.

Any decent model shop will be able to sell you Deans connectors, including me.:D

Water on your motor won't really matter to be honest.

The Tamiya connector won't last I'm afraid - ok for the mabuchi 540 but not much else. The deans you showed are right yes - if you want a few it might be best to look on ebay or elsewhere as I think you might be able to get bigger pack of them.

Not sure whats up with the cells / run time tbh without seeing it all.

Well the cells are not cold when they come of charge.... so I'm going to run it in the car park tonight.... and see if it gets better after a few charges....

You run a decent model shop then?

Cheers!

Well you have given me some stuff to look in to already Jimmy, so thanks for that, and I'll come crawling back again soon enough I am sure.

Now, lets get me some of them there connectors!

Cheers!

Having cleaned up the car, ditched the 3racing shock towers in favour of the plastic items, I ran the car slowly around the lounge, and sure enough, the wires and tamiya battery connector were warm..... does make me wonder why LRP sell an ESC rated down to 10T with a connector that will melt?!

Cheers!

Yes, thats a good question. I thought that when I bought mine too. The guy in the store said that if he was being cynical it could be because LRP know 100% you will need to cut it off but this will then give them the right (if they so choose) to reject a warranty claim. Hmmmm.

Interestingly, I charged the cells, and ran the car around the car park here where i live.... and she was flying... but then it stopped. What I have found is that infact the battery to ESC connector was fine, but the wires supplied with the LRP 12x2 motor have melted, and I suspect that was what had started to happen yesterday also. The wires on the ESC that the motor is connected to seem fine, and indeed seem heavier grade than thse supplied with the motor. Email going to LRP today!

Now it may have just been an illusion, but it seemed like the car was faster in reverse than forwards which seemed weird :lol: What might cause that, would that be motor related or something else?

Cheers!

ESC setup? It should change lights or something on full power - just make sure the ESC is setup right / or the transmitter.

Yeah, it is most likely user error of one sort or another.

Looking at your review photos, your ESC is soldered direct to the motor without connectors, so I think that may be the way to go as well.

Sorry to seem such a dummy, I'll get there and stop asking all those dopey questions soon enough :)