The Lithimon FAQ  

If you have a query about any aspect of the Lithimon product family, why not check whether the answer is in this Frequently Asked Questions page? If you can't find the information you want here, or on the other Lithimon pages, we have a fast-response email technical queries service: tech@dawnmist.org.


    Technical Questions

  1. Q. I use "governor mode" on my helicopter, i.e. a circuit which controls the 'throttle' automatically, based on the collective pitch setting. Do I still need a Lithimon?

    A. In short, yes. Irrespective of how the motor speed is selected (by a stick, or automatically), the ESC (speed controller) still works by 'chopping' the voltage to the motor on and off very fast and varying the ratio of on-time to off-time, and this is what gives rise to the Peak Pulse Effect. A Lithimon will give you just the same benefits whether you use a governor or a throttle stick to set the motor speed.



  2. Q. I am confused about how to choose which model of Lithimon I need, especially when using several batteries wired together. Can you give me some help?

    A. The choice is simply on the basis of overall battery voltage, which equates to the number of Series (S) cells in your battery pack. The number of Parallel (P) cells is not important. If you have multiple battery packs wired in series, then the 'S' numbers of the packs add together to give the total 'S' number; whereas if multiple packs are wired in parallel, the 'P' numbers add up instead. Thus, if you had a pair of 3S2P batteries in series, the total would be 6S2P, but the same batteries in parallel would total 3S4P. The total 'S' number of the whole battery pack dictates the Lithimon model you need: Lithimon 234 covers 2S, 3S and 4S batteries; Lithimon 5678 covers 5S/6S/7S/8S batteries, and Lithimon 9012 covers 9S/10S/11S/12S batteries. The 'P' number does not affect the choice of Lithimon needed.



  3. Q. I use a very high-voltage battery, i.e. more than 12 series cells (12S). The Lithimon range goes up to 12S (9012). What can I do?

    A. We are currently developing a "Lithimon HV" (High Voltage) for such applications -- please email our technical helpline for more information about this and a development timescale. Alternatively, if your battery pack is made up of a number of smaller packs wired in series (as HV packs almost always are), you can use a separate Lithimon across each section of the battery. For example, if you have two 10S packs wired in series, you can wire a Lithimon 9012 independently across each of the 10S sections and thus gain the full Lithimon benefits without waiting for the Lithimon HV to be launched.



  4. Q. Why are there three models of the Lithimon anyway? Why not make a single product that covers all batteries from 2S to 12S?

    A. The answer has to do with the energy storage capacitors that Lithimon uses to neutralize the Peak Pulse Effect. The energy stored depends on both the voltage and the 'capacitance' of the capacitors, and the physical size of a capacitor depends also on both factors. The capacitors on the LM-9012 have less capacitance than those on the LM-234, for example, but work at a much higher voltage -- and the higher voltage means that equal (or greater) power is stored, despite the smaller capacitance. In effect, there is a trade-off between voltage and capacitance which has to be optimized to ensure adequate energy storage in a given size and weight of unit, and the three models of Lithimon are optimized respectively for their own voltage ranges. This allows us to offer the optimum amount of energy storage (and hence best cancellation of the Peak Pulse Effect) for each voltage range given the size constraints. If we were to make a "one-size-fits-all" Lithimon, it would have to be much bigger than the existing models to maintain adequate energy storage across such a wide range of voltages.



  5. Q. I've read the manual but I'm still not sure whether I need to select Extreme, Heavy, or Medium discharge profile. Any suggestions?

    A. First of all, does your battery pack normally run down in 30 minutes or less? If it lasts longer than this, you'll probably want Medium, although if there is significant residual charge in the battery when the Lithimon indicates "discharged" (see below) you could switch to Heavy. Otherwise, and usually the case for electric flight, it's a choice between Heavy and Extreme. Start with Heavy, and move to Extreme if there is significant residual charge in the battery when the Lithimon indicates "discharged". You can tell this either directly, if you have a smart charger that can measure residual charge, or indirectly by measuring the off-load (i.e. with motor(s) off) voltage of the battery after you have landed -- if it measures over 3.0 volts per series cell (i.e. 9V for a 3S pack), you can switch to Extreme and make the battery last a little longer.



  6. Q. The instructions that came with my battery said not to discharge it below 3V per series cell, yet the Lithimon manual quotes figures lower than this for Heavy/Extreme modes. Why?

    A. The minimum voltage per cell refers to off-load voltage, ignoring the 'sag' that occurs owing to the internal resistance of the battery when current is drawn by the motor. The discharge profile is selected to compensate for this sag so that the equivalent off-load voltage is maintained at 3V or above. This 'sag' can be very significant, often as much as 0.6V per cell in electric flight applications. As long as you have selected the correct discharge profile, you won't over-discharge your battery by waiting for the Lithimon to bleep.



  7. Q. My 4-series-cell battery is quoted as having a voltage of 14.8V, while the Lithimon 234 specification quotes a voltage of 14.4V for a 4S battery. Is there a problem?

    A. No problem. This figure is a purely nominal voltage, as the actual voltage of the battery will vary with changing load and state of charge. Some companies quote the nominal voltage of Lithium cells as 3.6V and some as 3.7V; it makes no difference. The actual terminal voltage of the 4S battery in the example could range from below 10V to above 16V depending upon operating conditions, and the Lithimon will handle the full range.



  8. Q. I want to have the option of using NiMH/NiCd power when my Lithium pack is charging. Do I need to remove my Lithimon in this mode, or is it compatible?

    A. It's fully compatible and can be left in circuit. In fact it will improve Ni performance because Ni batteries do also experience the Peak Pulse Effect, just not as severely as Li. If the Ni pack has a substantially higher voltage than the Li pack, the Lithimon might flash green to indicate "wrong battery voltage" but you can quite safely ignore this when in Ni power mode.



    Ordering and Commercial Questions

  9. Q. I am not located in the UK, European Union or USA. Can I still buy online?

    A. Yes. The US Dollar price quoted includes shipping to any address worldwide, and PayPal supports many national currencies which can be converted into dollars. We regularly ship products all over the world.



  10. Q. I can't buy online (no credit card, maybe?), how else can I buy your products?

    A. You can order by mail -- we accept UK Cheques/Postal Orders (in Pounds Sterling (GBP)) or a Bank Draft in GBP drawn against a UK bank (you can obtain these from your local bank). You can also pay in Cash -- we accept GBP, EUROs and Dollars (USD). Most national postal services offer a service for sending cash securely by mail with a receipt signed by us when it arrives; please ask at your local Post Office about this. Or ask your local model shop to stock Dawnmist products if they don't already.



  11. Q. I am placing an online order. How long will it take before the goods arrive?

    A. We aim to ship all orders within one working day of receipt of payment. UK orders are sent by first class post (normally 1-2 working days to arrive). All export orders are sent by air mail -- this normally takes 2-3 working days to arrive in your own country, plus whatever time your local postal system takes to deliver it.



  12. Q. I run a model shop or model trade distributor and am interested in stocking Dawnmist products. What can you offer me?

    A. We offer industry-standard dealer margins and an attractive quantity pricing structure to bona-fide model trade retailers and distributors worldwide, making our products profitable to stock. We also supply free-of-charge promotional material to our stockists. Our products are fast-selling, highly reliable, and attractively packaged for retail. Please email us for more details and trade pricing: sales@dawnmist.org.




If you would like any further information about the Lithimon product family, please contact our technical helpline:
tech@dawnmist.org.

Back to Lithimon details