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British Beekeepers Association Official Forum 

  • Using some sort of mains supply for a vapouriser

  • Bee Hive building & a place to share howto's on equipment
Bee Hive building & a place to share howto's on equipment
 #8834  by NigelP
 11 Sep 2020, 10:14
AndrewLD wrote:
11 Sep 2020, 10:01
Yes - you did . You have said something akin to this would do the job. In plain language that is a recommendation that it is suitable - but it is not - at all.#

The aim of this forum is to help and educate people not to take issue over well meaning advice.
Akin means similar, not identical....
If you were being diplomatic you would have written, that's a great idea for getting from mains to 12v DC but perhaps one closer to the wattage of the vaporiser might be more suitable....one wonders why you didn't take that approach, rather then the confrontational one you did?
 #8836  by AdamD
 11 Sep 2020, 11:05
As an electronic engineer, permit me to comment.

An appliance that uses, say 120 watts, will need a supply capable of supplying more than that - to give some head-room; say 50% above, so a supply of close to 200 watts is what I would recommend in a 120 watt example. A car battery charger will probably not be suitable as it will only deliver a few amps (120 watts is 10 amps at 12 volts) in most cases and it is also expecting to have a battery on the end of it which will stabilize the voltage in the way that a heating element won't. Even if it can deliver the current, it might not work as expected or safety circuitry inside might shut it down if it is expected to do something it's not designed for.

A car 'fast-starter' thing if mains powered will also not necesarily work either as it is expecting a car battery to be on the end of it and the output voltage of the fast-starter could be way-off (too high) if not connected to one - or safety circuits could shut it down as the 'load' we are putting on it is not as expected. A battery powered fast/emergency starter usually has a sealed lead acid battery inside and could work; see paragraph below, next but one. (I use a 4Ah battery from an emergency car starter device). No need for mains in this case.

In addition we need to conder dragging a mains electricity cable around the apiary for any mains powered device. Do-able but perhaps not desireable. Note that an electric hedge trimmer is 'double'insulated' and designed for outside use.

It may not be necessary to lug around a full-sized car battery; most smaller sealed lead-acid ones from Yuasa and others will work although some are not designed for high current discharges so the specifications need to be checked. However, if you were to need to treat a large number of hives, a small battery might not last the distance. Example :- Using a 120 watt heating element, it will draw 10 amps from a 12 volt battery. A 10 Ah battery will last 10 amps for 1 hour. A 2 Ah sealed lead acid battery will therfore last 1/5th of an hour - 12 minutes maximum. Again, you would need to have some 'head-room' as any drawn current from the heater may be higher than specified and batteries don't work so well when cold.
 #8838  by AndrewLD
 11 Sep 2020, 11:38
AndrewLD wrote:
10 Sep 2020, 11:33
NigelP wrote:
10 Sep 2020, 10:28
You need an AC to 12 volt D C converter, something akin to this would do the job, puts out 120w
https://tinyurl.com/y4oxm8k2
The vapourizers I can find on-line are 140-150 watts; so something akin perhaps, but not the example Nigel gives because it is (I quote from the product description) "Suitable for devices up to 120W Only". Unless of course Nigel knows that the device you are using is rated up to 120 watts (OP did not say).
With the unit in question, it would automatically cut out above 120watts so you would have wasted your money.
I think my original response was sufficiently diplomatic.
Not sure why there is a fixation on 120watts. I say again, the ones available on-line are in the range 140watts to 150watts.
A good point about the intelligent chargers not accepting the vapourizer as a load. I'd have to try it to see but I am not inclined to risk any of my expensive chargers on this. My point was in response to the trickle charger idea and that ordinary chargers do not have the output but my workshop ones do. I went on to say - still not a good idea.
Would Adam care to offer his professional advice on the really big issue, which is the use of non-IP rated items in an outdoors environment? That's what can kill you.
 #8839  by AndrewLD
 11 Sep 2020, 11:46
AdamD wrote:
11 Sep 2020, 11:05
Example :- Using a 120 watt heating element, it will draw 10 amps from a 12 volt battery. A 10 Ah battery will last 10 amps for 1 hour. A 2 Ah sealed lead acid battery will therfore last 1/5th of an hour - 12 minutes maximum. Again, you would need to have some 'head-room' as any drawn current from the heater may be higher than specified and batteries don't work so well when cold.
Let's not overlook that the capacity of a lead acid battery is stated on the basis of an assumed draw, which is actually quite low. A high load such as 12 amps will exhaust the battery much quicker than the stated capacity suggests. Also, one should not take a lead acid battery down to less than half its capacity or risk shortening its life or even ruining it. I can probably find you the calculation if anyone really wants it.
 #8841  by AndrewLD
 11 Sep 2020, 12:25
and my last post on this subject:
Everything you need to size batteries to load and calculate how long they will last.
https://www.batterystuff.com/kb/tools/calculator-sizing-a-battery-to-a-load.html
 #8845  by Steve 1972
 11 Sep 2020, 19:27
huntsman. wrote:
11 Sep 2020, 12:07
IMO, if those commenting on this thread are not electricians, electrical technicians or electrical engineers, they should keep their breath to cool their porridge.
Sorry.. but i do not agree with that comment..
Jenky.