Seeking Advice for Lipo ESC and Brushed Motor Setup

[Bob_Saint_Louis]

Guys,
I’m looking to convert my current boat setup this from NiMH to Lipo, but still stay brushed. Due to hull design & construction (ABS) I’m concerned that full conversion to Brushed motor would make boat unstable. Here’s my setup:

Boat= Graupner Key West – Catermeran Hull - 28 inches,
2pounds 6 ounces (boat, motor & speed control – no batteries)
Brushed Motor = Graupner 700 Turbo (GR3308)

Previously I ran this set up with 12 Cells series & Octura 440 prop. I was pleased with this performance, but frustrated with shorter run times & the durability of NiMH batteries ( all my batteries are now shot, and I need to replace )

I’d like the lower weight, relatively longer run times of Lipo, and stability of Lipo battery life.

Question: I’m thinking I could run 2 2 cell lipos(prior 12 NiMH x 1.2 volts / cell = 14.4 volts divided by 3.7 volts / Lipo Cell = 3.89 Lipo Cells).

Does this make sense ?
What speed controller would you recommend ?
Thanks !

[jcald2000]

Yes, 4s or as you say 2-2s lipos in series = 4s.
Swordfish 200 Pro+

[jstolz]

Jim,

He is looking for a brushed ESC. Look into an Astroflight brushed ESC. I don't believe they come with a LVC, but you can get an external low voltage cutoff.

[Bob_Saint_Louis]

Yes - I'm looking for an ESC recommendation.

I already have a great Tekin Brushed ESC, but it does not have Low Voltage Detector for Lipo's, AND it has TWO Leads. Someone recpmmended adding a
Dimension Engineering Lipo Shield Low Voltage CutOff (LVC) (part # de-liposhld-32 from Offshore Electrics) but this LIPO ESC comes with 3 leads, and from what I can see, most lipo ESC's have 3 leads.

Is there a Low Voltage CutOff that will adapt to 2 leads from my Tekin ESC and 3 from the Lipo's ?
Or is there a ESC that will work for this application (4 Lipo's running a BRushed Motor ) ?

Thanks !

[siberianhusky]

The two wires go to the + & - battery terminals on the esc, the other end with three wires and a connector plugs into your rx, the esc plugs into the bottom three pins of the LVC unit not the rx.
It works with any kind of motor, it goes on the battery side of the esc not the motor side.

[paultbg]

@Bob-your Brushed ESC will work also with LIPO, they are just power source after all.
You can overcome the missing LVC by timing your runs and measuring how much you charge the lipos back.
Is not very complicated.
Regards