New and confused! Help with Mad Monkey PLEASE
 

Hi All

Really would appreciate some help. I have a new Mad Monkey, brushless, and am becoming more confused by the day! Can anyone help with the following?

1) After only a short time (a few mins), the car goes into a slow mode, and the blue light on the std Ansmann ESC flashes. If I turn car off and on, all seems fine again for a short while, but soon repeats itself. I checked the battery (LiPo 2S 20C 4000), and it read 7.5 v, after only a few minutes! is this right, does the blue flashing mean low battery? My also new HPI battery duff?

2) I fitted uprated Aluminium shocks, but one rear driveshaft seems to pop out of the diff occasionally. Checked the length of the shocks, and the std ones measure 95mm ctr to ctr, but the uprated ones are 5mm longer... Any ideas, as this 5mm contributes to the wrong driveshaft angle.

3) Can anyone recommend another LiPo that will fit? I think it need to be rounded, with deans connector. Looking for about 4000mAh.

Sorry for all of the questions, but a search has just confused me more!

Thanks

It could be a number of things, but check the simple things 1st.. try resetting the speedo & matching it to the transmitter using the set-up process for the speedo.
If your LiPo is reading low voltage after a short use this could indicate a battery fault. I know it's a rather daft question to ask, but have you been charging it on a proper LiPo charger at the same rating as the battery (LiPo's should only be charged at 1C or in other words if it's a 2S 4000 battery, only charge at 4000 on a 2S setting.

If the shocks are longer the shafts will pop out as the wishbones will drop too much when the car is in the air. You can limit the drop by putting some plastic tube on the shock shafts on the inside of the shock body - about 3mm thick tops should be plenty. RC fuel tube seems to work well or you could use an o-ring.... or just move the shocks to a different hole.

Any brick LiPo should fit, but for the monkey but ideally you need one with the wires coming out of the top rather than the side or with 4mm connectors built into the battery instead of wires & make up a flying lead to connect the battery, or you could go for the rectangular Plazma battery.

On the HPI you are probably using (i'm guessing it's the Plazma with a rounded case that looks like a regular stick pack with the wires coming out of the side. This battery will work fine (i use one myself as it's a BRCA listed LiPo) but does push the shell out slightly on the one side where the wires overhang slightly, all you have to do is make sure you put the balance lead in the gap on the chassis to protect it under the power wire & try to get the leads (including the end of the balance lead) under the battery strap, personally i have the deans plug near the motor with the wires going under the strap with the cable inset between the LiPo & the battery post located nearest the motor wires.

to add to the lipo question, did you charge the lipo before you used it?

i'm not familiar with the ansmann speedo, but could it be a thermalling issue?
When this happens is the speedo hot to the touch, or the motor extremely hot?

Well, thanks guys for your replies!

This is the battery I have:
http://www.apexmodels.com/gbu0-prodshow/101941.html
Yes, I have a fusion charger, set to LiPo, 0.5A 2S. Charged at this slow rate from new (2 weeks ago). Balance charged.

Perhaps I will see if I can return to the retailer. So is a reading with a multi meter of 7.5v after a few minutes low? Any links to any recommended straight fwd fit batteries?

Shocks - so I need to take them apart and fit some tubing. 3mm internal diameter? Anyone have a link to instructions and fuel tube required? I though about running a die up the shaft and cutting it down - recommended or a silly idea?

Thanks again

you should be charging at 1c or 4 amps really, 7.5 volt is pretty much flat, a charged lipo will read around 8.3 to 8.4 volts on your multimeter. on .5A you will take over 8 hours to charge the battery

OK, this is just about starting to make sense....

So as the battery measured 7.5v it must have been almost flat after a few minutes of use, hence the blue flashing LED on the ESC?

I was told to charge at 0.5a to preseve the battery. So could this be my problem, shall I increase the rate, or will this simply quicken the charge time?

Thanks yet again!

Without a doubt yes.
If you can set your charger to 4amps, then that it perfect for that battery.

From completely flat it will take an hour to charge then; and should read 8.4v on the voltmeter when fully charged.

Hope it helps :)

Just to be Newbie clear, could the reason that the battery isn't lasting long when fully charged (8.41v) be because I have charged too slowly? How can this be, as fully charged is fully charged?????

Thanks

Very true.
Fully charged = fully charged.

If you have tested after charging and its at 8.41v then something is wrong.

The battery sounds defunct and its not holding the charge anymore.

Easiest way I can think of to diagnose this, is to run with another battery from someone who can assure you its working ok.
If you still get the blue light and cut off power then something else wrong, but I would guess that (if you meter readings are right:p) its the battery thats the problem.

Is this the charger ? http://www.wheelspinmodels.co.uk/i/62617/

max 3amps charging, still less than a hour charging (always really topping the battery up).

I don't think 7.5volts is a discharged battery, someone may correct me.

You should be able to monitor the amount of charge that is put back into the battery. Remember your esc should have a 'lipo cutoff' I would have thought nearer to 6.5volts.

Perhaps you can find a local club, all will be pleased to help out and give hands on advice, perhaps something rubbing and over working the esc, thermalling issue as Jim has suggested.

This is the charger:

http://www.rcmightymodels.co.uk/shop...oducts_id/4803

http://www.sussex-model-centre.co.uk...d.asp?id=29083

so max of 4amps, perfect.

Fully charged the battery will read 8.4 volts, 7.5 volts will be about half charged and when it gets down to around 6.4 - 6.6 volts it's pretty much flat. Does the charger tell you how many MAH it's putting back in the battery? If so charge it back up and see how many MAH go back in, you should get a figure of 1600 - 2000 if you do the battery is fine.

I cannot recal seeing a MAH reading, only voltage going in?

Ok you may have to press something on the charger to see it have a look at the instructions, if it isn't able to display it it's no problem.
When you say a few minutes running did you time it? I would say it would take about 10 minutes to get that battery down to 7.5 volts.

Hi, sorry, I didn't time it, perhaps I should........ but why the blue flashing LED and reduced speed mode? The Anmsmann manual is not too clear, but suggests that this light is voltage related, with the other light (yellow/amber if I recall corectly) relating to cut out?

another thing to try, is to reprogram the esc to accept nimh's, i have come across this problem on 2 other ansmann bl esc's and fit a fan to the esc too.

hope this helps :)

I don't have any means of programming I'm affraid. Any idea which fan, and how to fit/connect?

Although if the blue flashing light does refer to voltage, I'm guessing this is not a heat type issue?

Thanks