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Author Topic: KD Perkasa Question  (Read 500 times)

Richard Houston

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KD Perkasa Question
« on: July 13, 2019, 07:40:24 AM »

I have been graced with recieving a 4ft(48") KD Perkasa boat, I know absolutely zero about the boat as its not new but from markings inside the boat it looks like its meant to run on 2x or dual 12v Lead acids or Gel's.


The boat is in great shape and comes with 2x Torpedo 800 Motors fitted, My question is a bit strange but very important, i'm currently converting the radio system from 40mhz to 2.4ghz, but the batteries is the issue right now I dont know what sizes to buy for the boat due to boat dimensions
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Richard Houston

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Re: KD Perkasa Question
« Reply #1 on: July 13, 2019, 08:25:07 AM »

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canabus

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Re: KD Perkasa Question
« Reply #2 on: July 13, 2019, 11:26:23 AM »

Hi Richard
Lipo batteries with cut the weight down by far and give you a longer run time.
These boats were a 50 knot speed demon.
Beautiful looking model.
These are not great on turning, so wide turning circle.

Canabus
 
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Richard Houston

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Re: KD Perkasa Question
« Reply #3 on: July 13, 2019, 04:29:19 PM »

I understand but the boat is clearly labelled on the inside as running on 2x 12v SLA, not sure about converting to LIPO, would it not damage the motors which are 12v I thought
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SailorGreg

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Re: KD Perkasa Question
« Reply #4 on: July 13, 2019, 06:16:29 PM »

No, LiPos will not damage your motors. 12V is 12V, irrespective of the chemistry that produces it.  A 3S LiPo is nominally 11.1V but around 12V when fully charged.  Switching to LiPos will save weight (if you need to) but will be more expensive than lead acid, especially as you will need to buy a charger that will suit LiPos.  A standard battery charger will not suit, but if you buy LiPos then the vendor can advise on a charger.

Frankly, if you don't need to save weight I would stick to a couple of 12V SLAs, which will be cheaper and easier - although if you haven't run the boat yet you probably don't really know if it's too heavy or not.  Based on looking at the model, I suspect the builder knew what he was doing, so stick with his scheme for now.  There are various sizes and shapes of SLA available, depending on their capacity (ampere/hours), so check the dimensions will fit your battery compartment(s). Component Shop is one vendor who does a variety of SLA sizes.

Greg

Richard Houston

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Re: KD Perkasa Question
« Reply #5 on: July 13, 2019, 08:23:35 PM »

Perfect answer, yes I have a Smart charger that can easily handle Lipo's but your right will stick with SLA for now, i'll be having a few of the other club guys to take a look tomorrow to decide on course of action for SLA size required(Dimension wise), yes will be using the compnent shop once I figure out dimension requirements
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Akira

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Re: KD Perkasa Question
« Reply #6 on: July 13, 2019, 11:06:25 PM »

Greg's answer is spot on. That said, I would offer another option, all be it an expensive one. There are Lithium Iron SLA replacement batteries available. Same size and case configuration as 12v 7.5 amp SLA's, but around 1/4 the weight. They allow a greater current draw than SLA's, charge faster too. Another down side is that they require a special charger, usually the battery manufacturer will offer them. If expense is an issue then this is clearly not an option, but the information is out there.I use these in my 60 inch Elco 80 footer and they are a perfect match.
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Richard Houston

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Re: KD Perkasa Question
« Reply #7 on: July 14, 2019, 04:58:04 AM »

Greg's answer is spot on. That said, I would offer another option, all be it an expensive one. There are Lithium Iron SLA replacement batteries available. Same size and case configuration as 12v 7.5 amp SLA's, but around 1/4 the weight. They allow a greater current draw than SLA's, charge faster too. Another down side is that they require a special charger, usually the battery manufacturer will offer them. If expense is an issue then this is clearly not an option, but the information is out there.I use these in my 60 inch Elco 80 footer and they are a perfect match.


Well I have a smart charger and balance boards and the likes but upto half the weight but around 10x the price, the price alone is insane.
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