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Author Topic: Brushless motors  (Read 836 times)

RogerG

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Brushless motors
« on: May 04, 2020, 05:43:01 pm »

Hi All,


need some advice on installing brushless motors.  My question is, do you HAVE to use Li Po batteries or will a NiMH or a Sealed Lead-Acid be suitable. Many thanks in advance.
Regards,
Roger G
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tsenecal

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Re: Brushless motors
« Reply #1 on: May 04, 2020, 05:50:08 pm »

you are not required to use any specific battery type.  the ESC may be tuned to offer options based on the type of battery...  ie built in low voltage cutoff.   some may be tuned for lipo voltages, with no option to choose a different type.  something to look for when selecting the ESC.
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DaveM

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Re: Brushless motors
« Reply #2 on: May 04, 2020, 07:35:00 pm »

Volts are volts - the motor won't know or care where they're coming from. That said, NiMH packs should be OK but I would strongly advise against using a SLA battery. The power required would very quickly flatten one of those old dinosaurs. If you have one then either retire it or save it for a tug (or hand it in at the nearest police station). They weren't intended for the level of current-drain required by even a modest motor. They also make good weights or doorstops...

Do take Tsenecal's advice about setting the low-voltage cutout on the ESC. NiMH packs are 1.1v/cell whereas LiPo should be >3.4v/cell.
DaveM
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malcolmfrary

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Re: Brushless motors
« Reply #3 on: May 05, 2020, 08:58:03 am »

If the brushless motors are doing the same job that brushed motors were doing, the same power supply will have the same reasults.  SLA are good for combining ballast with a modest current supply.
The most common application for brushless motors so far has been fast boats, where weight saving and high power are both needed.  In that type of boat, having got the required motor power and saved a bit of weight using a brushless motor, there is little point in weighing the boat down with a big lump of lead.  Fast boats tend to use a lot of power to go fast - this means high current continuously, almost certainly more than an SLA would be capable of delivering for more than a few seconds without causing itself damage.
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chas

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Re: Brushless motors
« Reply #4 on: May 05, 2020, 09:43:26 am »

I use brushless motors in 2 of my models with NiMH batteries without any issues. The 2 models are both fast scale, not racing boats so don't need very high power, only sufficient to do the job properly.. One of them is a Thornycroft, 1 meter long, lightweight build. I use a 2826 10 1400kv on 9.6 volts. Flat out it looks far too fast to be a convincing scale model, so I run on about 3/4 throttle, with occasional fun dashes up the lake. I can sail for 35 to 45 minutes.
 Lead acid batteries? I have 2, they're in a ferry model, it needs a lot of ballast.
I hope that helps a bit.


Charles



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john44

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Re: Brushless motors
« Reply #5 on: May 05, 2020, 12:58:52 pm »

Hi Roger, looks like you are just starting up with this hobby. Have you got any batteries?
More important have you got a battery charger. If you haven't a charger go for a multi charge
unit that does most battery types we use now, Nimh, lipo,s etc.
Nimh are probably the way to go, not lead acid.
You don,t say what type or size of boat it is you're thinking of putting the motors in.
As already stated if it is a fast boat lipo,s are better but require safety measures when charging
Also low voltage warning units fixing to their balance leads when in use.


John

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graze

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Re: Brushless motors
« Reply #6 on: May 05, 2020, 06:02:58 pm »

Just out of intrest is there a reason your against using LIPOS?
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