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kiwi k
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Help me please, i know the answer is simple but its fried my brain :sad:, so the help i need is this hopefully below is a diagram of my new battery set-up.

Currently i have removed lead battery and fitted a li-po (starts easy now) which is connected straight to existing feed leads, but my problem now is my unit use to recharge the lead battery, and now with li-po the charge will totally fry it, so i figured if i now fit a strobe i can isolate the battery and re-route the current to power the strobe.

My thinking was on/off/on switch but i'm over complicating the situation, as all i need is to switch from battery on and then battery off.

So i think if i join strobe wires into block, then just fit a switch in the positive lead from battery before the block to just cut the supply.

 

So can an electrical person confirm or deny if my thinking is correct ??

 

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The saves and best way to do this would be as Simon say.( you would have to switch it off every time you start - that is yust asking for something to go wrong)

What make of motor do you have?

Disconnect the charge wire (from your regulator) where it connect onto your your main positive wire that comes from the battery and you can connect your strobe over that charge wire .

Make sure that your  charge voltage is regulated ; your charge voltage  should be around 14.4 volts while the engine is running  at full speed as the lead acid battery would normaly keep the voltage down.

There was 2 ways they use to charge the battery:

1 use a bridge rectifier  - battery will keep the voltage  down.

2 voltage  regulator - it keeps the voltage electronically at around 13.8 to 14.4volt

If your voltage  goes up quite high it might be better to put a proper voltage regulator in before your strobe - unless the strobe can handle the higher voltage .

Casey

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The saves and best way to do this would be as Simon say.( you would have to switch it off every time you start - that is yust asking for something to go wrong)

What make of motor do you have?

Disconnect the charge wire (from your regulator) where it connect onto your your main positive wire that comes from the battery and you can connect your strobe over that charge wire .

Make sure that your  charge voltage is regulated ; your charge voltage  should be around 14.4 volts while the engine is running  at full speed as the lead acid battery would normaly keep the voltage down.

There was 2 ways they use to charge the battery:

1 use a bridge rectifier  - battery will keep the voltage  down.

2 voltage  regulator - it keeps the voltage electronically at around 13.8 to 14.4volt

If your voltage  goes up quite high it might be better to put a proper voltage regulator in before your strobe - unless the strobe can handle the higher voltage .

Casey

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Never charge a Lipo with anything other than a charger designed for LiPo charging, there is a serious risk of explosion.

You could use the engine charge to run the strobe with proper regulation, but the engine charge circuit must not be connected directly to the LiPo

If I was doing it I would simply forget the Engine charging circuit and use the Lipo for starting and strobe with charging as required between flights with a proper LiPo charger.

There's lots on the interweb about the dangers of mis charging LiPos. Eg http://www.propwashed.com/lipo-battery-charging-basics/.

 

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9 hours ago, PatPux said:

Never charge a Lipo with anything other than a charger designed for LiPo charging, there is a serious risk of explosion.

You could use the engine charge to run the strobe with proper regulation, but the engine charge circuit must not be connected directly to the LiPo

If I was doing it I would simply forget the Engine charging circuit and use the Lipo for starting and strobe with charging as required between flights with a proper LiPo charger.

There's lots on the interweb about the dangers of mis charging LiPos. Eg http://www.propwashed.com/lipo-battery-charging-basics/.

 

PatPux  Thats the reason for isolating the Li-po battery. because just incase somebody missed it 

Never charge a Lipo with anything other than a charger designed for LiPo charging, there is a serious risk of explosion.

If you'd read my post you'd notice i said existing charge would fry the battery !!!!!!!!!!9_9

Yes like said above i have fitted a Li-po battery, and for charging i own a ~Imax 6 balance charger, which gets used for charging said Li-po battery when its needed :P as its a dedicated charger.

Without pulling my wiring harness to bits and working out where every wire feeds too?, and then making a new harness not going to happen, thats why i posted the question previously.

so i will just carry on regardless and just check every open or closed circuit with my electrical tester, to make 100% certain that No charge gets back to the Li-po battery which is all i'm looking to Do !!

 

 

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noddyc i'm waiting on confirmation about strobe voltage range ?.

Currently with No battery connected on tick over the motor pushes out approx 4.4 volts and if i'm correct on 3/4 throttle will be approx 13.6 - 15.2 volts, but i need more info on strobe to know how well it will function with the low voltage, bonus is that its a Led light and high 18v+ will not effect it.

(And before i get hung drawn and quatered the tick over test was done with the rig securely bolted to a very long metal ladder arrangement and that was weighted at both ends.)

And No limbs were lost or put in any danger of being lost during this test.

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take the battery rectifier/charger out the equation - it's just added complexity you don't need.

power the strobe via the lipo directly if the strobe will take your lipo voltage, but you don't mention what that is ? 3s 4s 5s ?

If it is a 12v strobe, I'd suggest adding a 12v ESC or a step down buck converter. they cost about 2-5 quid. This will regulate the lipo to 12v for the strobe and will keep that voltage constant as the lipo discharges.

 

stu

BEng Hon Electronic & Electrical Engineering :-)

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14 hours ago, powerlord said:

take the battery rectifier/charger out the equation - it's just added complexity you don't need.

power the strobe via the lipo directly if the strobe will take your lipo voltage, but you don't mention what that is ? 3s 4s 5s ?

If it is a 12v strobe, I'd suggest adding a 12v ESC or a step down buck converter. they cost about 2-5 quid. This will regulate the lipo to 12v for the strobe and will keep that voltage constant as the lipo discharges.

 

stu

BEng Hon Electronic & Electrical Engineering :-)

The strobes Ive used have been quite tolerant of input voltage and I havent used  any regulation when using upto a 4S, It  just increases the flash frequency as the capacitor charges quicker with increasing voltage. Just noticed his photo shows a 5S......(not surprised it starts easily now with 18.5V), so that might flash the strobe a bit too quickly

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1 hour ago, powerlord said:

I got some of these a while back for my drones..

 

they are mentally bright.. would probably get ideal for PPG usage tbh and only 5 quid including ESC for up to 6s

http://www.banggood.com/Xenon-Night-Strobe-Flash-Light-Automatic-for-RC-Multicopter-p-1022677.html?rmmds=search

They look interesting, might try some of them. I built mine originally with one of these modules http://www.xenonflashtubes.com/12v-power-strobe.html. and a fresnel lense. This was bright enough to be seen on a gloomy day nearly 2 miles away when I was flying last year down in Cornwall.

 

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19 hours ago, powerlord said:

I got some of these a while back for my drones..

 

they are mentally bright.. would probably get ideal for PPG usage tbh and only 5 quid including ESC for up to 6s

http://www.banggood.com/Xenon-Night-Strobe-Flash-Light-Automatic-for-RC-Multicopter-p-1022677.html?rmmds=search

Thanks Stu might just order  some off these to try aswell, Nothing ventured nothing gained and not expensive9_9

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Just for completeness......even a charger designed for a lipo can still result in a very large fire. They don't usually explode, well not until the first cell that fails and is burning heats up the one next to it. I fly model planes and back in the early days of lipos (2001) I charged them on top of a 12" ceramic tile for safety. Bad idea. When the lipo caught fire the tile got so hot it just burned through the unit under it. 

Lipos should only be charged with a good balance charger that effectively charges each cell individually and hence keeps each cell voltage within spec. Also, use a fire-proof charging bag, because they do still go up in flames occasionally.

 

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Hi Kiwi k

The voltage range on strobes vary , I am not sure what it would be.

With those voltages on the charging circuit  I would yust put a rectifier  and large capacitor on it ,  to smooth  it and add  a buck converter to regulate the circuit as been suggested. 

That was what I was going to do to mine (I have a jpx which is 18V, I am currently  using a bosch 18v drill battery)  to give me a usb charging and  a  7.4 v point for my heated gloves .

I am trying to get hold of this battery for my polini 200 , it will solve my problems on that one.             http://bikegear.co.za/product/ultrabatt-multimighty-lithium-ion-battery/#jPanelMenu  

Casey

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