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>> Home > Tags > battery voltage

battery voltage
battery life
battery mount
battery pack
battery power
battery voltage
Voltage increasing via regulator by RNinMunich Fleet Admiral!   Posted: 15 hours ago
A somewhat confused question if I may say so Eric!😲 You can't 'regulate up' only down. The regulator's job is to produce a constant lower voltage from a range of higher voltages. I often use one to produce 5V for the RX and servos from a 12V SLA drive battery. A little 3 legged device (type LM7805) which looks just like the power FETs in a high current ESC. My version of a UBEC! 😉 What is this 'regulator' you have? Type number? Manufacturer? Photo? To get 12V from 7.2V you would need to use a Voltage converter (also known as an inverter). This works by converting the DC input from the battery to an AC voltage which can then be increased using a transformer. More elegant (and expensive!) versions use a transistor oscillator and amplifier. This uses hi-power transistors instead of the transformer. The AC output of the transformer (or amplifier) is then rectified back to DC. All this is very inefficient which is why it is normally only used for very light currents, where the losses are not so significant, and when there is no other alternative, not often the case! You can't beat the physics and you will never get the same power out that you put in. This leads to a basic design question:- What is the total current consumption of the load? I.e. the motors. A simple example:- Let's say that at 7.2V the motors draw 10Amps total, i.e. 72W (or VAmps). Assuming a utopian 100% efficiency at 12V this would equate to 6A. Due to the three stages of conversion; DC to AC, transformation / amplification of AC to 12V, AC back to DC, you'll probably be lucky to get an efficiency of around 60% to 70%. Thus if you stick 720W in you'll get around 430 to 504W out. Not much of a gain is it!🤔 Your battery would be exhausted in about 2/3 the time it is now 😡 If your motors draw more than 10A the problem just gets worse. So what is it you really want to do? If you just want to up the volts to your motors stick a 12V SLA or an 11.1V LiPo (3S) in and hope that you don't cook your motors! Frankly I don't really know why you're bothering, tugs aren't sprinters! If you want more pulling power with the existing setup try experimenting with prop sizes and pitch. Will probably achieve much more than fiddlin' about with voltage converters. BTW: All this assumes that the RX has it's own separate 5V battery supply or from a BEC in the ESC. Some clarification needed from your side. Cheers, Doug 😎

Mtronics and Lipo's by ads90 Commander   Posted: 11 days ago
The TIO has a safety low battery voltage cut-off for LIPO batteries whereas the Viper 15 does not have this facility. If you are confident in not running down your LIPO battery to below a 'safe limit' then you should be OK to just use the ordinary Viper.

motor sizeing by canabus Fleet Admiral!   Posted: 26 days ago
Hi Jim I used a Hobbyking D3548/4 1100kv , a car ESC (hk60A-SL)(electric fan on top for cooling), program card(HK PROG-CARD) and a 40mm 2blade prop(test out the one on the boat first). Battery a 3s 5800mah 30C Lipo. This is in my Sea Commander and gives a good turn of speed with a long run time. ESC set up:- 1 Cutoff Voltage for 3S=10.2 and 4S=13.6 2 Start Power Percent=5% 3 Advance Timing=4 4 Run Mode=2 5 Brake Force=1 6 Drag Brake Force=1 7 Neutral Range=1 8 Initial Brake Force=1 9 Reverse Force=1 Canabus

1.5v AA Li-Fe/Li-ion/Li-po batteries by RNinMunich Fleet Admiral!   Posted: 2 months ago
OK, found some! Interesting that they all quote mWh instead of mAh! I.e. energy instead of capacity! Power being V x I (Amps) divide the mWh rating by the nominal voltage to get an approximation of the capacity in mAh. Saves integrating across the varying voltage during a discharge cycle, i.e.'On Load' 😉 Thus these 3000mWh cells seem to have a capacity of around 1800mAh. Which is considerably less than the typical 2500mAh of an alkaline or NiMh AA cell. Also, to produce the output voltage of 1.5V from 3.7V Lithium chemistry the cells have an internal voltage regulator, which also must consume some power, albeit miniscule. Something else which can go wrong🤔 Summary; yer pays yer money and takes yer choice! Seem rather expensive to me for what they deliver. Depends what you want to use them for. Might be useful in my Sony camera but I wouldn't use them for any high current load in a model. OK perhaps for LED lighting circuits which only need a few tens of mA. Here a list of battery types, sizes and chemistries for reference. Cheers, Doug 😎

Mahogany in Scale by RNinMunich Fleet Admiral!   Posted: 2 months ago
Neither can I Martin! "The transmitter used two vacuum tubes wired as a multi-vibrator with a tank circuit to constrain emissions to somewhere near the 27 M/cs band (same as MHz, but that name came later). With not a crystal in sight, transmitter frequency drift and battery voltage drain was a problem, so careful tuning just prior to short flights was the order of the day." Cheers, Doug 😎

Graupner Jumbo 540 motors by Will-I-Am Sub-Lieutenant   Posted: 2 months ago
Doug, The 6volt battery is currently an NiMh battery not an SLA. The problem was that according to Mtroniks the minimum voltage to the ESC to adequately run the BEC connection is 6volts. That is why I was getting erratic control when the battery voltage was 5.6 volts. The action speed controller will work 2-12 volts and I am going to use a separate receiver battery as suggested by Dave Milbourn just to make sure. Regards Will

Graupner Jumbo 540 motors by CB90 Fleet Admiral!   Posted: 2 months ago
I think it would be worth the risk of running the DC Motors at 7.2v (NiMh) or second choise 7.4v (Lipo) and get rid of the 6v lead acid battery. The chance of damaging the motor is limited, the battery packs will be lighter than an equivalent lead acid, but will need to by a charger as well. Always put a fuse in line rated 5 amps below that of the ESC. Or buy two higher voltage motor? only £6.99 each plus P&P link copy and paste into browser address:-

Cheap motor for a quick fit, but what prop gents?... by RNinMunich Fleet Admiral!   Posted: 2 months ago
Mornin' (😲) Martin., First off; the Hornet ain't mine, wish it was 🤔 I had a look on the Lesro Models site to get an idea of what the prop would have to shove! Was surprised to see it is my hull with a different lid! The current kit is 80 quid BTW. To the motor / ESC; Yeah, you could use an 11.1V LiPo on that motor. BUT your ESCs probably are not LiPo SAFE! Which means that they won't have an automatic shut off or slow down function for when the battery is getting near it's Suicide voltage; roughly anything below 3.0V. Some say 2.7 but I don't risk that. So you would have to be cautious on the first runs and frequently check the remaining volts to learn how long you can run before you risk damaging the LiPo. If you can squash it in how about a 12V 10 cell NiMh? That should give you a good turn of speed with the 35mil prop. Bit heavy though🤔 I use an 11.1V LiPo in my Sea Scout with a 1000kV brushless. i.e. ca 11.100 rpm full bore, and that lifts her snout quite well as you have seen. Hope you find the motor, you seem to make a habit of 'mislaying' motors! Have you found the Supermarine yet? Apropos Supermarine; I've just been asked to renovate one 😉 Looking forward to that so I can see it's coil construction first hand. Will help me refine the mod instructions for you.😉 ESCs; mail me any printing on them and photos and maybe I can identify them and their capabilities. The switch makes me think maybe they do have BEC! The leads don't go nowhere cos it's only there to switch on the ESC / BEC. In my experience only ESCs with BEC have such a switch. Easy way to find out; set up an RX with a servo, plug the ESC lead into the RX, stick a battery on the ESC WITHOUT motor, switch on the TX and the ESC (move the switch to the end where two wires are connected) and see if the servo responds to the TX or any LEDs flash on the RX. Or just measure the volts across the red and black wires on the RX plug! If the ESC has a heat sink I don't think you need worry too much about current capability. Use your natty new Wattmeter to measure the current drawn by the motor as you run it slowly up to full speed. 😉 Don't think you need worry about volts either; all but the teeny weeny ones (like the fingernail size 3.7V ESCs I just bought for my Plastic Magic ships with only a 1S LiPo supply) can normally handle at least 12V, it's current that usually kills 'em😡 Sorry; Your electro-boards are still here, haven't been too mobile lately🤔 So I ordered some prepaid DHL labels (arriving Thursday) and will then get them to collect your parcel from me. Will email when they're finally underway. Cheers, Doug 😎

LiPo batteries by RNinMunich Fleet Admiral!   Posted: 3 months ago
Hi Pete, Do you have a Battery Capacity Checker? Like in the pics? Open circuit voltage is NOT a reliable indication of the battery's charge state😲 As you can see in the pics my two bats, 1 LiPo one NiMh, both show voltages above the nominal value. But the capacity / charge state less than half!! Be warned! Believe I did suggest to you to note the capacities before you left Hungary last time. Whatever - Have Fun😉 Cheers, Doug

Martin's Taycol Conversion Boards by RNinMunich Fleet Admiral!   Posted: 3 months ago
OK, In chronological order😉 No! The Wattmeter has to be spliced into the cable between source (i.e. battery) and the load, ESC and motor. As shown in example 1 in the instruction extract above. BTW 1: if your Wattmeter comes with instructions in Chinese Unwinese (Misstoodifold in the under number 29s😁) then use the above. Despite it's name it's primary use to us is to tell us the current the motor draws so we can select appropriate fuses. It will also tell you the mAh you've taken out of the battery, or put in when on charge. As far as I'm concerned the actual Watt measurement is relatively useless, except perhaps for 'Bragging Rights' 😁 Speccing the ESC should be done by checking the motor current specs and adding a good margin for safety. If no specs available use the Wattmeter to tell you the current drawn at full voltage from a DC source. If possible under load in the bath. Hang on tight😲 That only works for BRUSHED motors of course! Then use an ESC capable of twice the measured current. BTW 2; if you want to use your 27 / 40Mhz TXs you will definitely need the suppression capacitors on the motors, despite the partial damping effect of the rectifier, to reduce interference to your own radio. Fuses; I'll put 15s in to be on the safe side. If the Wattmeter / Ammeter measurements indicate less than 10A max then change fuses to10A and use a 20A ESC so it has some reserve. Or is operating within it's true capacity😉 Cheers, Doug 😎

Which battery? by marlina2 Chief Petty Officer   Posted: 3 months ago
I tend to use LiPo's but they can be temperamental and need the correct charger. They are smaller and lighter than NiMH and give you a much greater output. NiMH are similar in size to LiPo but are heavier and will not have the same sort of power available. Lead acid are the easiest to use in terms of charging but are much heavier and larger then the other 2 types but tend to be cheaper. Lead acid are a good option if you need the ballast or are not limited on physical size. Cost is also a consideration a good quality charger can be an hefty investment but will serve you well and if you buy the correct type will charge/discharge any battery type that you have. I have heard horror stories about LiPo's bursting into flames, which my son did with his RC car. this was down to him not understanding this type of battery. I have not had good results in terms of endurance with NiMh but Lipo's if correctly selected will last much longer, a word of warning here though, they will stop working suddenly with no indication like running slow etc so if using LiPo's you will, need an alarm on each battery. Lead acid is much easier to in terms of Voltage either 6 or 12v with real problems when connecting them in series or parallel for use or charging, a little harder with the other two types but not impossible. This has probably confused you even more but I am sure you will come the correct battery. I have to confess I have an interest in this build as I intend it to be my next project👍

LED Tug Mast Navigation Lights by RNinMunich Fleet Admiral!   Posted: 3 months ago
Hi Pete, JFF I built a little 'breadboard' (now where's my peanut butter!?😁) to test your LED lighting configurations. Theory and calculation is fine but there's nowt like an acid test😉 Pics attached of the results (Christmas tree😊). Difficult to capture the colours due to the very bright white LEDs🤔 Will play with the resistors to bring up the yellows and dampen the whites a bit. The 3 yellows at the bottom are the deck and cabin lights. The 4 rows at the top are the mast lights, red and green self explanatory! Applied (battery) voltage is shown on the meter top left, current drawn in mA on the meter to the right. The circuits work fine from 6.0V upwards. Current drain is approx- 110mA @ 7.8V (fully charged 6 cell NiMh) 103mA @ 7.5V (probable voltage after running a little while) 90mA @ 7.2V (nominal NiMh battery voltage. It will flatten out at approx this voltage after running a while - until it suddenly collapses at the end!) 75mA @ 6.6V (voltage of FLAT 6 cell NiMh battery) 60mA @ 6.0V curiosity! Below this some LEDs switch off. Brightness is noticeably reduced. I think we can increase some resistors to reduce the current drawn without reducing the lighting effect😊 More info soon, I'm still experimenting, then I'll start modding my own tug😊 Cheers, Doug 😎

What transmitter , receiver by catman Seaman   Posted: 3 months ago
The flysky fsi6/tgy i6 upgrades to ten channels for the price of a of Data cable at £3.00 from hobbyking and a 10 channel telemetry rx £15.00 some sensers at £7.00 so it monitors main battery voltage and RPM which is very useful especially the voltage . RPM handy for prop choosing I have done my tx and now all I have to do is figure out what to do with the other channels better to many than not enough Good set and expansion at low cost 👍

LED Tug Mast Navigation Lights by RNinMunich Fleet Admiral!   Posted: 3 months ago
Evenin' Pete, first instalment coming shortly in pdf format. A table, based on your excellent sketches of what you want to do, showing control element on the TX, function, number of LEDs in the cct or ccts, resistor(s) needed, current consumed, for various battery voltages. Example attached as jpg pic. Based on your measurements I am assuming that the searchlight is a 3V high brightness LED and all the others are 2V LEDs, and nominal current 20mA. This means that with a nominal 7.2V supply (Vs) for some circuits with 3 or 4 LEDs two parallel ccts will be needed. All will shortly be revealed 😉 I have optimised the resistors so that a) the LEDs don't fry when the batt is fully charged, 8V, b) that the LEDs can still turn on when the batt voltage dips to the 7.2V nominal. c) Only 2 or 3 values will be needed. Now have to convert my Excel file to pdf. Will follow this up with wiring suggestions, including the little Distribution Board with the resistors. I've tried to combine the lights you want logically considering how they would be used on the real ship. Stay tuned! Cheers, Doug 😎 BTW; the mods and resistors suggested in the table mean that the existing SMD resistors on the ccts board must be shorted / replaced with wire. Your wrapping wire (stripped of course!) will be ideal for this😉 Hope you have a small soldering bit!

LED Tug Mast Navigation Lights by RNinMunich Fleet Admiral!   Posted: 3 months ago
Hi Pete, since you are in the US try here, the OTHER RS😉:- Personally I prefer stranded wire as it is more flexible and less prone to break if you often have to remove and remake connections, like when you take the cabin off! It's slightly thicker so it's more a question of 'Will it fit?' Some model shops have (or used to!) a really thin stranded wire, as used for tiny 'rice grain' bulbs'. 2nd question: I assume your tug has an 800mAh NiMh battery like mine did. Correct me if I'm wrong, I don't know the new models. I propose to change mine for a 2200mAh NiMh. Can't use LiPo cos the Brushed ESC isn't LiPo safe; i.e. with built in cut off if the battery falls to 3.0V per cell - lowest safe LiPo discharge voltage. 3rd Question - changing motors; I've often wondered that!😲 Up to now I don't see any reason to. Maybe those guys want to enter Towing Competitions!? I don't. Also some folks are just not happy unless they are tinkering and 'improving' 😉 I might try to quieten the gearbox down a bit though 🤔 Teflon grease perhaps!? Cheers, Doug 😎