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Author Topic: Boat keeps cutting out  (Read 1186 times)

destroyer42

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Boat keeps cutting out
« on: July 20, 2010, 05:42:01 PM »

Dear colleagues,
Just recently my boat has started to cut out. She will go for about 10mins then just stop, it hasn't done that in the past. Any ideas?
the boat has brand new 12v 12 amp hour batteries,twin motor fuses, distribution board and a twin mixer speed controller. When i get it back to the bank i switch the main switch on and off and she comes to life. However if it has just cut out switching the main switch on & off does not do anything. I was wondering if it were a dry joint.

Any ideas on what I should try?
Regards
destroyer42
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Martin [Admin]

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Re: Boat keeps cutting out
« Reply #1 on: July 20, 2010, 05:59:13 PM »


It may be worth trying out in the domestic floatation chamber (bath),  it could be something overheating.....
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FullLeatherJacket

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Re: Boat keeps cutting out
« Reply #2 on: July 20, 2010, 06:43:13 PM »

Colin
(Sorry about the DHL man interrupting your call the other day!)

I get the impression that the boat has been similarly equipped (i.e. with the same ESC, DB etc) before this problem started, and that the only recent change has been the fitting of new batteries.

I reckon you've either not charged up the batteries properly or that they are somehow faulty (unlikely from new). The symptoms you have described would fit perfectly with that scenario i.e. the batteries quickly fall below a useable level under load; will not respond immediately when switched off and on, but recover some charge after "resting" for a while. The radio will stop working only if the regulator on the P92 is fed with less than 5.5v, so the batteries must be really flat!

To check the integrity of the installation remove the two new batteries and fit a known good 12v battery (fully charged), then run the boat on the water. If it goes happily for a while then the problem isn't anywhere in the electronics.

Are you using a charger sufficient for 12AH batteries? Did you charge them for long enough before you fitted them? I'd recommend a full 24 hour charge each, using a proper constant-voltage SLA charger of at least 1000mA output. If you have connected the two batteries in parallel without some form of diode then one may be back-charging into the other, with the result that both will go flat in fairly short order.

Keep us posted.

FLJ
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destroyer42

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Re: Boat keeps cutting out
« Reply #3 on: July 20, 2010, 08:32:33 PM »

Hi FLJ,
Thanks for replying. The batteries are the same ones that I bought especially for the boat and I have used them for the last 9 months. I always keep them fully charged. The motors are the MMB 900 and they only get warm running at full throttle. It seems strange that this problem has only occured in the last couple of weeks. I did find a loose connections on one of my tamyia plugs, but I rectified that. I also renewed the main power on/off switch. I really don't know where else to look. (I hate electrics).

Regards
Colin aka Destroyer42
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FullLeatherJacket

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Re: Boat keeps cutting out
« Reply #4 on: July 20, 2010, 11:00:50 PM »

I don't see anything in your reply to change my suspicions, mate, but you'll have to get 'someone who knows' to give it a good work over. By rights the only thing that can have caused this has happened in the last two weeks, so you need to examine exactly what you've changed/done to the model in that time.
FLJ
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Dreadstar

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Re: Boat keeps cutting out
« Reply #5 on: July 20, 2010, 11:56:55 PM »

If you haven't already done so,change all of your Tamiya plugs to perhaps Deans plugs. After a while,Tamiya plugs have a habit of losing conductivity in a high drain environment. I learnt this when racing R/C cars.
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