Suitable battery pack

[john isherwoodParticipant @johnisherwood65744]

Hi.

I have recently bought a second hand model yacht which has a motor & speed controller installed but would like some advice on what would be a suitable battery pack?

The speed controller is called: electronize electronic speed controller type 43 but not much else. The DC motor size is obscured by it's housing although I can read: 10.106.005.

I have photos but cant see a way of uploading them onto this forum.

Any help would be appreciated.

Thank you.

John.

[john isherwoodParticipant @johnisherwood65744]

[Kev.WParticipant @kev-w]

To add photo's to a post, you have to create an 'Album' (top bar above heading with camera icon) on here & upload your pics to the album, you can then use your album pics in your posts.

Edited By Kip Woods on 11/07/2016 10:49:03

[john isherwoodParticipant @johnisherwood65744]

Thank you Kip.

I'll convert them to Jpeg and get them uploaded this evening.

[john isherwoodParticipant @johnisherwood65744]

Sorry about the photo size. I've limited resources at work. If not legible I'll redo them tonight.

[Dave MilbournParticipant @davemilbourn48782]

John

When you say model yacht do you mean a sailing yacht with an auxiliary motor or a luxury motor yacht with no sails? Some photos of the complete model from a few different angles would help us identify it.

It would be very useful if you could measure the diameter of the motor case; that would give me a good idea of the type. Also can you tell us the diameter of the propeller and the number of blades it has, please? The speed controller is a very well-known and reliable type and will handle 12v up to 15A – more than adequate, I'd have thought.

I make my photos between 300-600kb for the albums I have here.

Dave M

[john isherwoodParticipant @johnisherwood65744]

Thank you Dave. I'll take some photos tonight and update the photos.

[john isherwoodParticipant @johnisherwood65744]

Hi Dave.

Thank you for your response earlier. I've added some more photo's to the album so you can see the boat. It has a three bladed brass propeller which measures approx 1 1/4 inches (30mm) diameter.

The motor casing is 1 1/4 inches (30mm) in diameter and 2 inches (50mm) in length.

If you can help me choose the right battery pack I'd be most grateful.

Thank you.

John.

[Dave MilbournParticipant @davemilbourn48782]

The motor is either a 3- or 5- pole Johnson 380/385 type. The problem is that one is more than twice as fast as the other on the same voltage! If we get it wrong then your model might either move at the speed of a twig or a F1 hydroplane.

The speed controller has four thickish wires; the red and black are for the battery. Could you see if there are connectors or a single connector on these wires and, if so, take a photo of them/it? I suspect that if a 12v battery has been used then they will be spade connectors and therefore we're looking at a 385 motor. If there is a single connector e.g. a Tamiya type, then it's more likely that a lower voltage NiMH pack been used, which would indicate a 380 motor. A 30mm 3-blade prop is more 385 territory but not everyone sticks to convention.

Fun this, isn't it? Like long-distance CSI for old fogies!

Dave M

[john isherwoodParticipant @johnisherwood65744]

Dave. You're a star! You are quite right it's the old Tamiya type connector which it came with it. I've added a picture to confirm. So I'm guessing a 6v NiMH pack might have done it.

Does that mean I can't run it on Lithium Battery pack? Is there any advantage using NiMH? I'm never quite sure.

Your help is very much appreciated.

John.

[ashley needhamParticipant @ashleyneedham69188]

John. If you have a Lipo battery (of 2s) this will be fine for a 380, just use one of those small "low voltage level bleepers" in the boat as the ESC you have is not a Lipo capable unit (does not have the relevant voltage cutoff setup). If buying a new battery I would say a Nimh would be better from the longevity point of view. Lipo are lighter and deliver more current/keep the voltage better when under load and really only need to be used for FAST boats or for size/weight reasons.

​All my 380/400 motor equipped boats run on the "standard" 6-cell Nimh packs, 7.2V no probs.

Ashley

[Dave MilbournParticipant @davemilbourn48782]

John

I would guess at 7.2v, which was the standard "buggy" pack a while ago. If that's the case then there is absolutely no reason why you can't use a 2S LiPo pack. I'd recommend changing the ESC connector to the Deans type, sold by Component Shop, and having the battery connector socket to match. NiMH packs are not as efficient as LiPo but some folk are scared of LiPos because there are rumours that they can explode for no reason. That is tosh. **LINK**

Dave M

[ashley needhamParticipant @ashleyneedham69188]

A couple of recent projects have been transformed by using Lipo, despite nominally the same voltage (7.2-7.4) they do seem to up the power delivered to the motor substantially.​ Tradeoff…speed verses longevity

Deans connectors much better than the Tamiya ones

Ashley

[john isherwoodParticipant @johnisherwood65744]

Thank you for your help Ashley. I think I'll go for a 6 volt Nimh pack and take it from there. I will update the thread and let you know if it works.

John.

[Dave MilbournParticipant @davemilbourn48782]

Ashley makes a good point. NiMH packs, if properly treated, should give you over 1000 discharge/recharge cycles, whereas you'll be lucky to get 100 from a LiPo pack. That said, you may already have a suitable LiPo pack (which was what I assumed when I read your question).
Don't fast-charge a new NiMH pack for the first 4 or 5 cycles. I never exceed the 'C rate' which, for example, would be 2.5A for a 2500maH pack. If you find that you need a pack recharged in less than an hour it might be better to have a spare pack already charged up.

DM

[john isherwoodParticipant @johnisherwood65744]

Cheers for all your help guys. I got a 7.2 volt 3000maH NiMH which seems to power the motor nicely. However my boat is still not quite ready as I managed to blow the speed controller by plugging it into a Lipo battery. :¬(

I'm just waiting for a new water proof one I've ordered, so that's a good tip there. Don't plug a Lipo into something you don't understand. But then I'm guessing you all know that. I seem to always end up learning the hard way.

I will hopefully have my boat ready for a maiden voyage this weekend.

Thanks again for all your help, I'll let you know how I progress.

John.

[Malcolm FraryParticipant @malcolmfrary95515]

Volts is volts, amps is amps, the source does not know or care what the load is as long as the load is within its limits. Similarly, the load does not care where the volts and amps come from as long as i) there is enough ability to supply the current demanded and ii) not too many volts.

The only way a LiPo is likely to damage a circuit is if its voltage was too high for the circuit being driven, or, and this applies to any battery, if the + and – were reversed.

[john isherwoodParticipant @johnisherwood65744]

Thank you Malcolm.

I actually connected an 11.1 volt Lipo. The motor did run and in both directions for a very short while before it died. I then charged up the battery and reconnected it expecting it to work but all I got was the clicking sound of the contacts opening and closing and no power. Tried again with the new 7.2 v NiMH and still dead. I thought there might be a reset button on it but then figured it was knackered.

John.

[john isherwoodParticipant @johnisherwood65744]

Hi Guys.

I managed to get my boat up and running. I ended up using electronic gear from my aircraft in the end. Works well with both 7.4 & 11.1 Volts although a little bit too quick with the 11.1. The only thing I don't have is reverse but it performs so beautifully and so manageable doesn't matter. I'm chuffed to bits!

Looks lovely on the water and after half an hour of running just a spoon full of water had collected through the prop-shaft but nothing unusual or wasn't expecting. I reckon I'd get an hour out of it probably a lot more if I learn how to sail! The motor runs a little bit warm but as long as I don't over use it in one go it'll keep on sailing.

Thanks again for all your help, I'm off to the boating pond again tomorrow and hopefully meet a few more people with their boats.

I bought that boat off ebay for £26. Best £26 I've spent in a long time. What fun!

Happy boating guys and girls. I'll catch up with you again soon no doubt.

All the best

John.

[john isherwoodParticipant @johnisherwood65744]

I got the boat out on the pond again yesterday and got it under full sail. Goes beautifully, even better than I was expecting. A fellow model boater helped me set up the sails for the wind conditions and I was as happy as Larry just sailing up and down the pond. She looks so graceful and got quite a bit of attention from onlookers.

My next idea is to get some radio controls on the sails. I still have an additional two channels and servos to look at connecting an arm of some sort. However, it's all future stuff I'm considering but already very happy with it's performance. I'm looking forward to next Sunday morning.

Happy boating.

John.

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