ET0422 PHOTON 2.1FW SYSTEM W/11.0R 3450KV MOTOR/60A ESC

[Jonathan LucasParticipant @jonathanlucas22088]

hi has anyone have experience with the ET0422 PHOTON 2.1FW SYSTEM W/11.0R 3450KV MOTOR/60A ESC as i seem to be have lack of power it starts of with loads of power and then goes into a limp mode after a few seconds and remains like that untill I disconnect the battery and leave it standing for a while any help would be appreciated and im running it from a 12v mead acid battery if that helps

[Jonathan LucasParticipant @jonathanlucas22088]

Lack or reduced power from a photon 2.1fw combo

[Charles OatesParticipant @charlesoates31738]

Whilst I don't know this set up in detail, I'm very doubtful of your power supply. Lead acid batteries are not generally suitable for high current set ups. You need to change to a li po battery. I'll bet that the current is causing a voltage drop in that battery, the ESC then goes into limp mode to get the model back.

Chas

[ashley needhamParticipant @ashleyneedham69188]

Jonathan. Welcome to the forum.

​What he says really. That is a very high Kv motor, what's it fitted to?? sounds like an EDF or fan.

​Lead acids great for large applications requiring ballast, and relatively low power motors.

My MFA Fantome originally specified a 7Ahr 12v SLA on two 800`s and seemed to run OK for a reasonable time, but of course the kit was designed umpteen years ago when this would have been really the only battery choice for something like this. I particularly wanted to equip the boat as per the original equipment just to see how it went, but have replaced the SLA with a 12v Nimh and, no surprises, the performance is much better, no doubt due to the fact that the Nimh probably weighs less that a 1/4 the weight of the SLA!!

Ashley

[Dave MilbournParticipant @davemilbourn48782]

I couldn't agree more. I've forgotten the number of times that SLA batteries have been used in inappropriate circumstances and caused exactly this problem.
Those intended for car starter motors are specially designed to deliver a sudden burst of high current and then receive a constant recharge from the alternator as the engine runs. Others, called leisure batteries, are designed for powering motor scooters, golf caddies and the accessories in a caravan. They have specially-designed plates to cope with continual current drain and are usually of very large physical size and capacity.
The type generally bought by modellers is intended for low-current applications such as emergency lighting and alarm back-up, and they should only be considered for models which have low current motors e.g. car blower motors in tugs, pulling <10A. At best you will obtain about half the indicated capacity, even if you run them at these low currents. This situation is, to say the least, unlikely with a brushless motor which is doing over 41,000 RPM. Incidentally, what sort of model boat needs a motor which will deliver this degree of speed? This particular one is held out for use in 1/10 scale model cars with gearboxes.
As Chas so rightly says, you need to use a battery capable of delivering high currents e.g. LiPo. You are wasting your time with SLA's which, in my opinion, are at their most efficient when used as weights in the workshop.
I've absolutely no doubt that this subject will continue to crop up, despite my rantings writings!

Dave M

[ashley needhamParticipant @ashleyneedham69188]

Dave, you continue to rant write, after all, if we had no alternative views on things, we would never get to the truth (whatever that is,)

​Ashley

[Malcolm FraryParticipant @malcolmfrary95515]

What Dave said.

Back when a lot of today's models were designed and their drives specified, SLA was the only game in town. You just had to put up with their inability to sustain a high current drain. The instructions were never updated, so quite a lot of kits still carry old specifications. Updating an old model with a modern power plant means doing the same for its supply. Same with "grandfathering", doing a modern spec boat with similarities to one from the past. SLAs are a good combination of ballast and moderate power store, but the last thing you want in a performance boat is ballast.

[Jonathan LucasParticipant @jonathanlucas22088]

Hi thanks for the reply’s I’m all fairly new to this and it’s my 1st boat build I’ll look into getting some LiPo battery’s but I was wondering roughly how long will they last

[Dave MilbournParticipant @davemilbourn48782]

I was wondering roughly how long will they last

That depends on a lot of things. Drive the model flat out all the time and the answer is not long. Slow down = longer. Using too big a prop and/or with excess revs will flatten them quickly. Partially charging them will reduce duration. Then there's the temperature, thickness of cable used, type of connectors etc etc etc. My advice is to obtain a wattmeter and measure the average current drawn ON LOAD i.e. in the water. I use this one, which is small enough to be carried in most models, but there are many others available **LINK**

That value will divide into the battery pack's capacity in Amp.Hours and give you an indication of how long a pack will last. There's loads more on the subject in my article here **LINK** In terms of duration you'll not get anything commercially which will outlast LiPo packs.

I'd still like to know what type of boat you have with that beast of a motor in it. If you've got that wrong then you're fighting a losing battle even before you start.

Dave M

[Jonathan LucasParticipant @jonathanlucas22088]

Hi sorry the boat in question is nothing like what you would normally build it’s a bait boat I would post some pictures but it won’t let me load them for some strange reason

[Dave MilbournParticipant @davemilbourn48782]

Jonathan
Bait boats generally require long duration and good torque as opposed to warp-speed, and you have a hugely fast motor here – a bit like fitting a Ferrari F1 engine into a quarry dump-truck. If you can provide some details about the boat then maybe we could point you in a better direction for propulsion.
If you check out the FAQ's in the RH column of this screen then there's a section on creating a photo album on the forum website. Usually the reasons for photos not uploading is that they are not in JPG format or they are much too large.

BTW there is a whole dedicated board for Bait Boats on our "fellow" forum Model Boat Mayhem here **LINK**

Dave M

[Jonathan LucasParticipant @jonathanlucas22088]

Dave

I know bait boats are normally slow but when i brought the boat the moter was burn out and still on the fm system so i decided to give her a complete refit and update to a digital setup and just brought what i was told in the shop being a complete novice and to be fair it did set me back a fair bit but i thought what the hey ill have a faster boat than normal so i would like to run this set up as its all installed now i just need to sort the power issue out i was wondering if i builtt a pack oyt of 18650 batterys would it be enough for the duration unless i can link LiPo batterys up to double the capacity

Jon

[Jonathan LucasParticipant @jonathanlucas22088]

A few pictures from my album i know i the wiring is rough but im gonna tidy it up once ive got it running right

[Dave MilbournParticipant @davemilbourn48782]

I'm sorry but I've no idea what 18650 batteries are. Perhaps the shop where you bought the equipment may be able to help you but my expertise with bait boats is limited.

DM

[Jonathan LucasParticipant @jonathanlucas22088]

Posted by Dave Milbourn on 18/03/2018 20:38:08:

I'm sorry but I've no idea what 18650 batteries are. Perhaps the shop where you bought the equipment may be able to help you but my expertise with bait boats is limited.

DM

18650 lithium pencil shape battery and are the typical battery used in ecig’s and can also be found inside most cordless drill batteries with a rating of 3.7v with average of 35amp and 3000mah capacity they also use them on electic bikes and can be made up to what ever volts and capacity ive seen packs made up to +70v on bike packs and they weigh next to nothing

[Charles OatesParticipant @charlesoates31738]

Jonathan, please read Daves article that he posted a link to, it's rather important that you understand some of this stuff before you spend a penny more. I'm not the worlds best on hi power stuff, I build scale, but I'm seeing some problems looming. Just for starters, that Huco coupling with that motor, it'll get shredded. A frankly insane amount of power in a bait boat, a lack of knowledge about lipo batteries. Lipo are superb if treated correctly, bloody dangerous if abused. Learn some stuff and come back with questions, people on here will keep you straight.

Would I be right in guessing that whoever sold you this stuff specialises in aeroplanes? High revs, extra low weight.

We'd much rather help than see you spend a wad and get discouraged.

Chas

[ashley needhamParticipant @ashleyneedham69188]

Couldn't agree more….the sight of cooling coils on a bait boat motor is unnerving to say the least….

Ashley

[Malcolm FraryParticipant @malcolmfrary95515]

Posted by Dave Milbourn on 18/03/2018 20:38:08:

I'm sorry but I've no idea what 18650 batteries are. Perhaps the shop where you bought the equipment may be able to help you but my expertise with bait boats is limited.

DM

About 18mm diameter, 65mm long. Probably a bunch of them in your laptop.

They do make excellent power stores for displacement boats, but need lots of care picking the right ones to get an appropriate C rating. Care is also needed as I recently found out that the same size and shape can be NiMH – the label needs reading to avoid surprises.

Using the motor in the heading will need a gearbox or pulley drive to turn the high revving power into torque rather than heat. The shape of the hull will determine the maximum economical speed, putting more power into driving it will not make it go much fast but will drain the battery quicker. Usually a bait boat needs a relatively large, slow-ish turning prop that can do its job of moving water quietly. This moves the hull efficiently, and doesn't frighten the fish away.

[Dave MilbournParticipant @davemilbourn48782]

A little light research tells me that these are Li-Ion cells, not LiPo's. I've also found that a discharge rate of about 12-15C is the best you'll get at the moment, while LiPo's can go up to 65C.

So far then you have an unsuitable motor and a coupling that will probably burst apart, and you are proposing to use batteries which you won't be able to solder together as a pack and which won't handle a third as much power as the LiPo alternatives. I imagine the existing prop on the bait boat is either a high-pitch 2-blade plastic one or a large diameter multi-blade ditto. O, and some of that domestic electric cable you have may overheat and melt the insulation with the current involved. How many problems do you want – especially as a beginner?

Jonathan – if you really want advice then it would be to take back the motor (or sell it on) and buy an 35mm or 42mm diameter outrunner of maybe 750kv; invest in LiPo packs and forget the 18650 Li-Ion cells; check the prop size against the motor and the boat (i.e. ask here) and replace the coupling with a heavy-duty flexible one e.g. SHG's MiniFlex.

On the other hand if all you want is to hear the answers you were hoping for then you've come to the wrong place. As Chas says, we'd rather not see you discouraged.

Dave M

Edited By Dave Milbourn on 19/03/2018 11:29:22

[Charles OatesParticipant @charlesoates31738]

If you want to frighten yourself, look on YouTube at what happens if 18650 cells are connected badly, or abused. Whamo, fire and fumes and injury.

There are some poor quality clones out their too!

The care and skill needed to make a pack up is huge. Just buy a suitable battery from a good specialist like component shop, Cornwall model boats or similar.

It amounts to this. You want a nice safe bomb. That's not something to cut corners with.

Chas

[Steve Walker 1Participant @stevewalker1]

This has been a very informative little chat, even if I do feel a bit sorry for Jonathan. Like being told to go and stand in the corner.

Nevertheless, I have just been building eezybuilts for my granddaughters and sailing unpowered yachts so far. Now thinking about moving into radio and building bigger models so the comments have really made the point. I suppose my comparison would be like going into some ‘refurbished’ houses and seeing wiring that is just waiting to blow up!

Memo to self: Must re-read DMs article.

Cheers, Steve (and good luck Jonathan, takes a bit of moral fibre to go back to the drawing board)

[Dave MilbournParticipant @davemilbourn48782]

My apologies if anyone feels I was a bit harsh but there's that "cruel to be kind" thing which sometimes seems to be necessary. I'm 100% sure that none of us who replied had any desire to look clever at Jonathan's expense, and if he was sold that motor after he'd explained what it was for then I'd love to be the guy who takes it back to the moron who sold it to him. Now there's someone who needs to understand the consequences of trying to be clever when you really know nothing.
Jonathan – a 60A brushless ESC will do the job you need it for, as long as it's forward and reverse, so that money's safe (as Jim Bowen might have said). A 2G4 radio will also be the one you need, so another smile for that one "in the bank". If you've not yet bought the battery pack then follow Chas (and me) to Component-Shop.co.uk for a good choice of LiPo batteries. They also sell outrunner brushless motors, good-quality 14AWG silicon-covered stranded cable and gold-plated bullet connectors – in fact all the stuff you need except a coupling and a prop.
We're rooting for you, mate – honest – and none of us is going to make a penny out of you. That's what Forums are all about.

Dave M

[ashley needhamParticipant @ashleyneedham69188]

Yes, what DM said.

So far Jonathan only seems to bought motor(s) and possibly couplings which are unsuitable, so really there is not much going to waste here.

With a much lower Kv motor and steel u/j he should be ok, with no need for water cooling, and of course then there are just the batteries to consider.
I think we can safely say Lipo or Nimh. Personally I would Nimh it just for the longevity of the packs, but that's just a personal choice and the man person at component shop may offer advice on this matter..

​A propeller has not been mentioned yet. Jonathan, are prop sizes and type specified, or is there a tunnel into which the props fit and if so how big?

​Ashley

[BanjomanParticipant @banjoman]

There is, I think, a photo of the existing prop in the album created by Jonathan: **LINK** …

Mattias

[ashley needhamParticipant @ashleyneedham69188]

Yes so there is!! difficult to say how big but I am guessing it is not small….45 or 50mm??

Ashley

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