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>> Home > Tags > lipo charge

lipo charge
charger
lipo charge
royal charter
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lipo charge
Bluebird K7 by BOATSHED Commander   Posted: 2 months ago
I see that's a battery charger. I was thinking about a 12v power supply box I have. Can this be done from any lipo battery charger. I don't want to kill my one by doing something that it wouldn't like. It's an Elysium LX60B.

Bluebird K7 by Midlife306 Captain   Posted: 2 months ago
Hot wire foam cutter: I started off by watching just about every video on YouTube on the subject. I then bought a few meters of 0.25mm NiChrome wire. At first I thought I'd just need a vertical bench top cutter. An unwanted shelf was liberated from a kitchen unit to use as the base, a couple of 2x1's were screwed underneath to give clearance for the wire connection. A piece of MDF was used for the upper arm. To give some adjustment underneath a block of wood with a screw in one end for the wire to wrap around was screwed to the base in just one position so the block could pivot. I drilled a clearance hole in the end of the upper arm for a long bolt & put a small slot in the end of the bolt to wrap the wire around, a washer and spring were used to give the wire some tension. When the wire heats up it expands so you need something to maintain the tension. Wrap the NiChrome wire on the screw underneath, put it through a hole cunningly placed in line in the base & up to the slot in the bolt in the upper arm, compressing the spring at the same time. Now that's all sorted get 2 pieces of normal wire, attach one to the screw underneath & one to the bolt on top. This is the bit where I found conflicting information on YouTube, people used all sorts of different things to power their cutters, batteries, pc power supplies & resistors, model railway power supplies, laptop chargers etc etc, everyone recommend different voltages & amperages. Luckily my Lipo charger can be sued as a power supply so I started messing with volt/amp settings, I didn't want the wire to glow red as that's too hot, I ended up using 10 volts & 2 amps, it works a treat. Unfortunately this cutter does have its limitations, throat depth etc. I decided I needed a hand held cutter, going off what I'd learned from the bench cutter this was a doddle. 2 pieces of 7mm steel bar 300mm long, 2mm hole in each end. 1 piece of 30mm square pine for the handle, 8mm hole through each end. Smack bars through holes in handle, get 2 pieces of normal wire, attach one to each hole at handle end, I just twisted them on & taped everything over. Now here's the trick with the other end, when you attach the NiChrome wire make sure you squeeze the bars together a little to give the tension, attach the other ends of the wires to the power supply & away you go. Like any tool I guess you get better with practice, lol Cheers Wayne

Battery problems by RNinMunich Fleet Admiral!   Posted: 2 months ago
Hi Patto, forget the 'watt meter' and consequent P=IV -> I=p/V conversions! What you need to measure is the actual current drawn, especially the stall current, if you can manage that without getting any fingers chopped off 😡 On the lake anything can choke the prop so just testing 'free running' is not the whole answer. Sounds to me simply that your setup is drawing so much current that any battery or accu will go flat in a few minutes. Your example of a 5300mAH (i.e. 5.3AH) means that in perfect (!) condition, fully charged and almost zero internal resistance (int. cell resistance wastes power so buy the best quality you can possibly afford) it can theoretically supply 5.3 Amps for 1 hour. or 53 Amps for ~ 6 minutes (1/10 hour). and so no. LiPos with C values of 130 sound great BUT the discharge C value is related to the AH rating. So taking your example of 5300mAH = 5.3 Ah 130C = 130x5.3 = 689Amps! The Accu would supply that for ~ 27 seconds before departing to the great recycling centre in the sky! If you ever decide to try such an experiment PLEASE let me know in advance and I'll fly over the record the event for posterity 😉 Seriously though folks: I can't comment on the prop/motor setup, one of my weaknesses - I always check my stalled motor current draw with an ammeter before selecting the ESC - but as an electronics engineer I do have some idea about power supplies and circuit requirements etc. Can't imagine that your setup exceeded the 160A (short term remember!) rating of the ESC so that seems to be faulty, but you still need to find out what current your setup will draw under severe load i.e. stall. If just holding the boat cause blow ups then something else is fundamentally wrong 🤔 Bit long-winded perhaps, much of the above makes sense but not the whole story, time to cut to the chase I thought. MEASURE THE CURRENT! Good luck. Doug 😎 By the way the above comments about lead acid & hi current are OK. They are more useful for long term supply of low to medium currents. I still use them in some larger scale models (~ 1.5metre naval ships) as they provide useful ballast (i.e. payload) instead of JUST ballast! The 20HR of your lead acids refers to the Hourly charge Rate, i.e 1/20 of the capacity in AH, in your case 7/20 = 0.35A or 350mA.

Li-Poly batteries by RNinMunich Fleet Admiral!   Posted: 2 months ago
and Good So! I think a lot of people (without the benefit of a long career in electronics) needed a 'Wake Up Call' on the dangers of and correct handling of LiPos. When possible try to find the manufacturers specs. in the net. I only buy from dealers who also post the specs. as PDF. No Spec. No Buy 🤔 The best manufacturers also print the max charge and discharge rates on the LiPo / LiFe etc pack itself. Rule of thumb: Max charge 2C, Max discharge; depends whether you want to run for ca 1sec or an hour or two 😉 Remember: 1000mAH (or 1AH) means the accu (strictly speaking LiPos etc are accumulators and not batteries 😉) can theoretically deliver 1Amp for 1 Hour IF hi quality and in perfect condition 'In this the most perfect of all possible worlds', or 2Amps for 1/2 hour and so on. But if you 'drain the tank' completely it will probably be ruined. Cheers Doug 😎

Li-Poly batteries by rolfman2000 Lieutenant   Posted: 2 months ago
My use of lipos involves drones (racing and camera), fpv fixed wing long range aircraft, and boats (mostly reasonably fast electrics). And my charging regime is to number all my similar cells, so all can be rotated, evenly used and charged. I normal charge twice, then balance charge the third. This has kept all my cells with even capacitance and in good condition. I say that, so far (touch wood) that I haven't managed to puff or blow any packs.

Li-Poly batteries by pmdevlin Fleet Admiral!   Posted: 2 months ago
to add to that, its also regarded as good practise to balance charge the lipo, using the balance lead, and and appropriate lipo charger, I believe all lipo chargers have this facility. This means the cells are all equal when fully charged, and you can view this on the charger display. It also means that none of the cells will be overcharged, and risk fire etc. The down side is that as the charger enters the final stage of balancing and achieving fully charged, it takes a while, as the current reduces, so patience is a virtue, and never leave unattended whilst charging, that applies to all chemistry, I have seem a nihm explode due to over charging, its not just this lipo myth that is risky!😉

Battery problems by HoweGY177 Lieutenant   Posted: 2 months ago
Hi Patto, Sounds like you aught to be running on a decent lipo. The motor is probably taking more amps out of the battery than it can maintain. Lipos are much much lighter than lead acid and can give a higher discharge rate. The dicharge rate is the 'C' rating of the lipo, the higher the number the greater the discharge capacity. If the 'C' rating is too low the battery will start swelling up and its life expectancy greatly reduced. Go for the highest you can afford with the greatest capacity and always use an alarm with the battery, it plugs into the little white plug and can be set so when the battery gets to a set voltage an alarm sounds indicating to stop using it until it is recharged. A 3 cell will give you the required 12volts. The 'C' rating now goes up to 130 in the more expensive lipos but an 80 will probably suffice. The higher the amperage of the lipo the longer running you will get. A 2500 may only give you 8-10 minutes whilst a 4500 (cost just under £50) will give you up to 20 mins. You will have to check your speed controller to make sure it is compatable with lipos, a few are not. Remember you will need a balanced Lipo charger, I only spend about £20 or less but they only charge lipos, quite often the more expensive ones will charge a variety of battery types. I'm not an expert on electronics my knowledge comes through personel experience. With the lipo you will get better performance as the lead acid weighs the boat down. Good luck.

Li-Poly batteries by nasraf Commander   Posted: 2 months ago
The link to rchelicopters.com that pmdevlin has indicated I found very informative and I think should be read by all those using lipo's. In addition if they follow its recommendations is likely to save them a lot of money as to the life they will get out of their batteries. One thing I discovered was the meaning of the two "c" values shown on the batteries which from what previous contributors have said looks a bit confused. From the web site article the lower of the two numbers is the maximum charge rate that can be applied to the battery without causing its immediate destruction i.e. assuming a capacity of 1000 ma.hrs and a "c" of 5, 5 amps would be the absolute maximum charging current. However if this rate is used the number of charging cycles that can be done before the battery is seriously damaged would be greatly reduced. The author of the article recommends that the rate should never exceed 1 c if you want to get a good life. The higher "c" rating is in general better understood and is an indication of the maximum short term discharge rate that can be drawn. Going back to an example of a 1000 ma.hr battery a "c" of 25 would give a discharge current of of 25 amps but not for long and the internal battery heating would not do much for the battery life.

Battery problems by Dave M Fleet Admiral!   Posted: 2 months ago
Hi Patto I agree with what has already been posted, but it would help if we knew the size and type of prop you are running with your brushless motor. Fast large racing props do not work well with brushless unless your battery can provide the very heavy sustained current required. As Haverlock suggests a Wattmeter will allow you to select the best prop for your set up. LiPo power will give you all the speed you need but at an initial high cost as they require special chargers and correct management. You could use NiMh batteries which are lighter than SLA and are more suited to high discharge currents. You can get these in 12v packs and 5000mAhr would be a good starting point. If your motor is cutting out it is more likely the ESC is the culprit due to too high current draw. Another possibility is that the propshaft is too tight, it should turn freely with no tight spots and have thrust washers at both ends. Dave

Battery problems by Haverlock Admiral   Posted: 2 months ago
A quick check on the specs of your motor /esc combo states its good up to 5s LiPo. So step 1 get a watt meter ( cheaper than burned out motors ) Step 2 check with your bank manager ( or wife) for available funds Step 3 buy the biggest 4s or 5s LiPo you can fit in the available space. you will also need a LiPo charger do not attempt to skimp on that step LiPo batteries need special handling and can be spectacular if you do it wrong. You have not mentioned the prop your using if you use the watt meter you can play around with different props so the current used by your setup heads towards the point you pick twixt performance / running time. If you do go LiPo you will also need a battery monitor part of the careful handing includes not discharging them below around 3.3 Volts per cell. 3s =3cells 4s=4cells etc. So if you go 4s then you should not discharge below 13.2V. http://www.rchelicopterfun.com/rc-lipo-batteries.html http://www.4-max.co.uk/pdf/prolong-life-lipo.pdf some text on the care and feeding of LiPo batteries. The reason for your problem is a simple case of battery chemistry a lead acid accumulator cannot deliver a high current for extended periods gasses on the plates prevent the electrolyte coming in contact so the battery loses power. After a while the gasses are re dissolved and the battery can then go on providing power. Nothing wrong with the battery its just a case of wrong tool for the job.

Li-Poly batteries by pmdevlin Fleet Admiral!   Posted: 2 months ago
thats prety much it Alan, but be warned, chinese c rating and mah tends to be overstated, the bottom figure being exagerated, and the top one really only there for very short bursts, its more abount the make of the lipo If your present packs have puffed, one or more of the cells has either over discharged, or couldnt take the draw, once puffed, its pretty much had it. I have used slightly puffed lipos oin a boat, but would never use them in a plane, its just not worth the risk if it fails, and it probably will

Motor Mounts by pmdevlin Fleet Admiral!   Posted: 2 months ago
Mtroniks do have lipo friendly vipers, they are call "tio" I recall, if that is written on the cover you can set upo for lipo, if not then its imperative you have some sort of alarm as dave says, they plug into the balance lead on the lipo, and are current sensitive, so need to be the right way round to work. The ones I use are here, and also can be pre programmed to sound at a given low voltage. I use 3.7v on a boat, and 3.8v on a plane. Ant lower and they take longer to charge. If over discharged they are generally finished. There are ways to recover them, but its regarded as bad practise. Nims can be discharged fully, but are now really yesterdays technonlogy, heavier, and not any cheaper these days! https://hobbyking.com/en_us/cell-checker-with-low-voltage-al... Paul

Motor Mounts by Dave M Fleet Admiral!   Posted: 2 months ago
Hi Steve Yes I intended to use silicon to fix the motors on the Perkassa. Works well and acts as a damper to any noise. The battery really depends on your speed controller as that may have a max voltage of say 12v. It's not a big model so I suspect a 3 cell 11.1v at 2200/3000 mA would suffice and provide plenty of power for the two motors. If you have a 7.2 NiMh available I suggest you try that and see if its fast enough. A 7.4 LiPo will give more endurance and speed so a 2 cell may suffice. LiPos do need protecting from over discharge so make sure your ESC has such protection or buy an add on unit that warns you when the battery voltage is too low. The ESC version is better as it cuts or reduces the current before damage is done. The Amp/Hr rating gets dearer the higher you go, so its down to you as to what you buy. Higher ratings will give you more speed but also longer running times. Glad the coupling worked. Dave

from the Philippines by Dave M Fleet Admiral!   Posted: 4 months ago
Hi Wellard I think we need a bit more info to give helpful advice. Electric or Gas depends on the noise level nuisance. May not be a problem for off shore use. Probably greater endurance than with electric but not as good for the speed you envisage. As speed is not important (3-4Km/h) then a brushed motor may be preferable to brushless. Generally the prop should be about the same diameter as the motor case. Larger props will require some form of reduction unit to reduce the load on the motor. Sounds like there will be plenty of room in the hulls to carry a good power source and as you are operating at some distance SLA is possibly better than say LiPo where discharge voltage is important. I think you may have a problem with the range (20-30Kms) as this is somewhat greater than the normal range of domestic RC sets. As you are off shore there may be additional problems with wave height as the signal may be obscured when the model is in a deep trough between waves. At the end of the day you need a motor prop battery combination that will move the craft thro the water at the required speed and last for the full duration of each sail. It's quite a large model and I suspect will need say two 800 size brushed motors to allow for wind/waves and current. I suggest you come back with your thoughts as you may have specific requirements to fit in with other equipment you are instaling. dave

cabin cruiser by Dave M Fleet Admiral!   Posted: 4 months ago
Hi I avoided mentioning LiPo as you are handing the completed model to possibly a novice. NiMh would be my choice and depending on the budget I would get the highest amp and voltage you can manage. There may be a min voltage requirement depending on the ESC you choose. She will also need a charger for the NiMh and possibly the Tx/Rx if no BEC on the ESC. Sounds like you will achieve your goal and I am sure the lady concerned will be well pleased. Dave