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mattharri

Loss of speed!

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it all suggests battery issues to me, ,you can use a volt meter if it has a dummy load built in , if you can get use of one set it to 3A load and see what the voltage droops to , if it drops below 7.2 when battery has just been charged you will know the battery is dead, a standard multi meter doesnt simulate the load so you will have to have the battery connected to the esc and at the cutting out point when checking with one of those.

hope you get it sorted , ;)

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You have a 4000mAh batery, so charging at 1.0A rate should mean ca 4 hours charging from flat to fully charged. You can charge at 4.0A for that battery assuming the charger can produce that, or 2A for 2 hour charging.

Sounds more and more to me like a battery issue, just can't deliver the current being asked of it by the ESC

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Think we are getting close to the answer now. My charger can charge at a rate of 5A but was advised to not go above 2A to prolong battery life.I will repost when I've tested battery.

Thanks everyone for the support.

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I agree this doesn't sound like an ESC issue. With the motor you are running you may still want to upgrade your ESC as your next modification, it will definitely get warm. If you ever run on sand, the ESC cutting out happens a lot faster. You definitely seem to be having a battery issue.

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Aye, if your battery got red-hot during a charge, even if it seems fine now, it may very well be a gonner. NiMH chemistry is pretty stable for the most part, but overcooking the cells can cause lasting damage.

The odd behaviour you reported when turning one back wheel by hand does still concern me a bit, so that might still warrant further investigation.

Either way, I agree that the ESC doesn't sound faulty. Tamiya ESCs are known for their reliability, and their thermal cutout system is one of the best out there. They almost always shut themselves down before suffering any permanent harm. I really abused mine during my early days in the hobby, and they are all still going strong.

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Evening all.

Battery has been tested and is not holding charge at all. Need to buy a new battery but don't want same thing to happen again. Old one was an Orion sport power 4000. Dudd after about 10 charges. Any recommendations for a replacement. Also thinking of a motor upgrade.Was looking at the Tamiya super stock RZ. Need a battery to support this should i buy both together. Would I need any further upgrades (pinion, esc ) or can I just plug in and play? Looking at 50-60 quid for both, all suggestions appreciated. Cheers.

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By the time you have bought the Tamiya Motor and ESC ( I think you may need a new ESC to power it?) you may as well get a cheap brushless combo.

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Evening all.

Battery has been tested and is not holding charge at all. Need to buy a new battery but don't want same thing to happen again. Old one was an Orion sport power 4000. Dudd after about 10 charges. Any recommendations for a replacement. Also thinking of a motor upgrade.Was looking at the Tamiya super stock RZ. Need a battery to support this should i buy both together. Would I need any further upgrades (pinion, esc ) or can I just plug in and play? Looking at 50-60 quid for both, all suggestions appreciated. Cheers.

hi,

what type of charger are you using ? , i ask as the charger may have killed the battery and if you buy a new battery you dont want that to happen ,

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Battery charger is a Vector AC/DC NX85. Charges from 0.5A to 5.0A. Only ever had it up to 2.0A.

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I've had a couple of vapextech nimhs for a few years and they've been good, powering all sorts of brushed and brushless motors. They've always performed when lesser nimhs have given power delivery problems. I have 5000mAH packs so more than capable running a tz/bz/ or >=9T brushless motor.

I'd hold off a motor change until you know what a good battery will do.

If your charger will cope with lipo batteries perhaps now is as good a time as any to experience the extra ooompf they cam provide. You will need to be careful as to which will fit so if this is an option seek advice !

You'll be sorted soon and the good times will roll again ;)

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I've had a couple of vapextech nimhs for a few years and they've been good, powering all sorts of brushed and brushless motors. They've always performed when lesser nimhs have given power delivery problems. I have 5000mAH packs so more than capable running a tz/bz/ or >=9T brushless motor.

I'd hold off a motor change until you know what a good battery will do.

If your charger will cope with lipo batteries perhaps now is as good a time as any to experience the extra ooompf they cam provide. You will need to be careful as to which will fit so if this is an option seek advice !

You'll be sorted soon and the good times will roll again ;)

thats partly why i was asking about the charger , sadly it doesnt do lithium tech batteries ,

mattharri , if you want to stay with ni-mh then here is a couple of tips to help the pack live longer , first charge should be at a low current , around 500mah has worked for me in the past , this eliminates any chance of cooking the battery and reduces the chance of false delta peaks,

when running for the first time find the most open space you can and try and keep full throttle as much as poss and run until it slows down , its this even and quite hard discharge that wakes up the battery chemistry , then , most important! let the pack cool for at least 4 hours before recharging at half C ,=4000 pack charge at 2A , you can use higher if you want but whatever you choose should be used all the time ,

ni-mh hold their core temp for a long time and charging even a warm battery causes false peaking and over heating during charge , = dead battery.

always try to run the car until it is showing obvious slowing then stop , never run until the car is crawling , and try not to use the car for a minute then stop and have cakes and tea then go back and use again for a couple of minutes.... as this causes what is known as 'memory effect' and the battery will mimic this during charge causing false peaks at each point where you stopped using it through its discharge cycle ,

time the charge ,, if its a 4000 at 2A it should take around 2 hours to charge , disconnect after this , never leave the pack connected as your charger does this ,

, when it has finished charging it keeps trickle charging , this is very very bad for ni-mh batteries and i dont know why so many chargers do it ,

try not to charge your battery then leave it for a few days, always put it away after running and then recharge before you want to run it .

its all a bit of a faf about but it does help protect the battery , i had to learn this as i had scary amounts of money invested in stupidly expensive ni-mh race packs years ago , TBH i cant be bothered with it all and went over to li-po about ten years ago and never ever looked back.

better luck with your next pack and do consider making the switch to li-po when funds allow, hobby king have made it cheap and easy,

all the best ;):)

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It's very very hard to kill s Nimh packs though or mine would be dead too. I had the same charger you have and for want of a better work it was carp. I suggest you off load it on eBay and get a cheap smart charger like turnigy accucel 6 and give it a go on that you should be able to breath life into it no problems. They are around 25 quid and you need a suitable laptop charger around 50watts.

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It's very very hard to kill s Nimh packs though or mine would be dead too. I had the same charger you have and for want of a better work it was carp. I suggest you off load it on eBay and get a cheap smart charger like turnigy accucel 6 and give it a go on that you should be able to breath life into it no problems. They are around 25 quid and you need a suitable laptop charger around 50watts.

i have never had any luck with ni-mh as have many others , its why li-po took off in such a big way , li-po shows up ni-mh for what it is, an almost redundant technology.

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I have both lipos and Nimh and for the most part I agree but I have yet been able to kill a Nimh and some of mine have bee under water not used for a year etc. Not particularly well looked after and still not dead. I wouldn't buy a new Nimh but I wouldn't throw them away either. In my opinion the battery will be fine once cycled afew times using a good charger.

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I have both lipos and Nimh and for the most part I agree but I have yet been able to kill a Nimh and some of mine have bee under water not used for a year etc. Not particularly well looked after and still not dead. I wouldn't buy a new Nimh but I wouldn't throw them away either. In my opinion the battery will be fine once cycled afew times using a good charger.

that would be great news for mattharri if he can, but he has said the battery got 'very hot' during one of the charge cycles , in my experience that would suggest that one or more of the cells had a massive rise in internal resistance and that indicates that one or more of the cells is dead and irretrievable by cycling regardless of charger ,

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Possibly I hear ya. I still say ditch the nx thing and get a cheap smart charger it makes the world of difference and means a failure would be far less likely in future. Plus you can use lipos

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Possibly I hear ya. I still say ditch the nx thing and get a cheap smart charger it makes the world of difference and means a failure would be far less likely in future. Plus you can use lipos

agree 100% , the turnigy ones on hobbyking with one of their cheap lap top type power supplies would come in at around £25-£30 shipped , add a cheap nanotech or zippy lipo and nancy's your transvestite uncle :D:lol:

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agree 100% , the turnigy ones on hobbyking with one of their cheap lap top type power supplies would come in at around £25-£30 shipped , add a cheap nanotech or zippy lipo and nancy's your transvestite uncle :D:lol:

I had to read this twice, first time I was just confused. LMAO!! Good Friday fun man! :lol:

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Definitely the battery, the stop start kangaroo behaviour is the battery dipping low on voltage. Buy a 3300mah it above as the 4wd cars drain the battery quick. I have a 3300mah battery in my twin 15 turn motor wild dagger and when fully charged lasts for ages. Lots of punch too. Old batteries are false economy I used to buy on eBay, vapotech if you are in the UK, are a good make in my opinion. (That is what I have.)

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...and try not to use the car for a minute then stop and have cakes and tea then go back and use again for a couple of minutes....

Nice.

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I've had similar behaviour to this in my thundershot running it recently. I was running a tuned 27 turn motor, with a TEU101 I fitted with a big ally heatsink I made myself. Running the ESC on 8.4V (Above its rating I know) the car would not accelerate smoothly and was jerky and slow. The ESC did not get hot, it just couldn't cope with the power draw on acceleration.

Mattharri, if your looking for recommendations for good speedos from modelsport, you can't go wrong with the mtronics series. The ECO27 is around £20, it's completely waterproof, has programmable reverse on it, and is good for a 9.6V battery. They are also very compact, which is an important issue when dealing with squeezing everything into a hotshot radio tray. The only downside is that they are only rated for 27turn motors, but MTronics do a whole series of waterproof speedos, just depends on how hot a motor you wish to fit.

Before replacing the motor and speedo, I would look at the ezrun brushless combos on ebay. They are very good value for money, and a 13.5T, 10.5T, or 8.5T will make a great installation. I've run my re-re hotshot with the 8.5T combo, and it's on the borderline of what the transmission will handle (This is on NimH, I think if I ran it on LiPo the diffs would disintegrate). A 10.5T or 13.5T combo would make a sensible upgrade.

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Evening all. Been away on hols for a week but just taken delivery of a vapextech 4300. gave a good slow charge @ 0.5A for 7 hrs and Hey Presto the beast is flying again! Just wanted to say thanks for everyones input. Happy days are here again :D .Think its actually quicker than when new suggesting battery was a bit duff from new. Wont be getting another one of them. Looking for a motor upgrade now, was thinking gt or dirt tuned ? Not looking to change the esc so think super stock may be too much. Or will it ? Am also thinking of getting a little brother for it to play with. Like the old school stuff eg Fox, Falcon, or was thinking maybe a super shot. Really enjoyed the Hotshot build and cant wait to start the next one. Sooo addictive. Look forward to your replies regarding motor or should i maybe start a new topic?

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Motor wise the torque tuned is a bit more powerful - it sits between the silver can and the sport tuned. Sport tuned is a good upgrade, not too expensive and will work with the existing ESC no problem, Super stock faster again but power hungry and its hit n miss as to how well the ESC will cope (some people have no issues, but its more than Tamiya recommend) - you might get away with it in a lighter 2wd buggy but maybe not in a 4wd vintage one.

Glad you're sorted, Vapextech batteries are great for the money.

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