Bestek Inverter

Hi all

Having precisely 0 experience in "off grid" camping, i read up about these inverter thingy's and plumped for a Bestek 400w inverter.  Reasonable price (£40 from Amazon) and reviews and seemed to match my humble power needs - little LCD TV, DVD player, phone charging etc.

Its a nice looking bit of kit, sturdy and easy to get to grips with.  Plugged it into a 12v outlet (from leisure battery), turned it on and whirrs into life.  I plugged the 60w TV into solitary plug socket and hooray, the TV worked.  

There are 4 USB outlets as well which haven't used yet but no doubt will come in useful.  

So, quite happy with the bit of kit, the size and feel of it.

BUT - at time of writing (clues appreciated) i plugged a 2 plug extension to it and plugged the LCD TV and DVD player in (60w & 6w) and the TV turns off when the DVD player turned on.  

Also, TV turns OFF also when the water pump comes on lol!!  Oh nothing is straight forward lol!!  

I dont think its the inverter, something to do with my setup no doubt.

Rob

It might be due to the initial power-up current draw.

Most, if not all, electrical devices have a significantly larger power draw when first starting up, vs the current draw they need whilst then running.

Alas, I can't offer a solution, but I'd suggest that's the cause?

Yeah i'm a bit disappointed in the outcome as my power needs pretty basic.

In 2 different scenarios, the TV simply turns off a) when you run the water pump and b) when i tried to plug a 6w DVD player into extension cable.  

I'll be back on it tonight so i will consider your useful feedback - thanks 

if you have some USB sockets commected directly to the leisure battery (not on the inverter) you can charge phones there..

similarly, is the to really 12v but has one of those 'brick' connectors to allow it to connect to 240v? if so, dump the brick and connect the to again dorectly to a 12v socket from the leisure battery...

DVD player....may be mains only....however, perhaps treat yourself to a 12v TV with a built in DVD player..

sorted, you can return the inverter....

I've had two inverters in the past, and never had much success with either.
One failed to do what I'd bought it for, which was to charge up my laptop. Someone with more electrical knowledge than me said it was to do with the half sine wave output.
So I bought a better one, that tripped out the microswitch on the control panel when I plugged anything in..
Both are now it the attic and I've bought 12 volt USB outlets and a 12 to 20 volt charger for the laptop.
It's surprising how much power these inverters draw just to convert 12voltDC to 240voltAC.
Al

although our van is primarily 12v, for off gridding purposes, we do have an inverter (500w) which runs a (mains only) Sky+ HD box..
I need to get a low wattage hair dryer so that OH can use it when on THS sites...

Peter Brown wrote:https://www.youtube.com/watch?v=ABNhmr3p51s

See at link above - very good inverter.  I guess your problem is quickly dropping 12v supply from tired battery.

Yeah i've spoken to a few technical folk at work who have suggested similar.

I've borrowed a multimeter to see if that provides a clue or two.

Thanks for the link and reply!

If you are connecting through a cigar type socket it may improve things if you hard wire to the battery to decrease the voltage drop. I realise your not using the inverter at full capacity but bear in mind at full capacity it will be drawing something around 35 to 40 amps.

Peter Brown wrote:

Mrgeoffrey wrote:I realise your not using the inverter at full capacity but bear in mind at full capacity it will be drawing something around 35 to 40 amps.

The socket will probably be fused at 10 amps, 15 amps max so this should not be an issue.  The unit is effectively limited to 120W unless a special installation is made in which case a MUCH higher battery capacity will be needed.

Agreed but I thought it was worth pointing out as those new to inverters tend to think if it says 400 watts that's what they can draw.

Also if the supply wire to the socket is of any significant  length and probably relatively small it would help any voltage drop issues by hard wiring to the battery with suitably sized wires.

I'm not sure the OP gave their battery capacity but agreed if they are using a single domestic battery of circa 100 ah then a draw of no more than 120W would be a sensible limit.

Thanks all for all your help.

Basically the leisure battery is a AH (20h) 70amp.  Not huge but "enough"?

But in a nutshell the inverter works like a treat when connected direct to battery via croc clips.  The problem seems to be when i connect it to any socket in bank of 4 cigar lighters which is in turn connected via a 2 pin plug thingy.  

I will post this quandry with pictures to more appropriate thread but thanks all for the suggestions and help.  Much appreciated.

Good stuff looks like you've sorted it by experimentation. 

The voltage drop between the inverter when wired through the cigar socket looks like it's where your problem is.

If it were me I would permanently wire the inverter to the battery with crimped on connections as close to the battery as you can sensibly get.(with a suitable fuse)

Also if you are intending to spend much time off grid you may need to look at increasing the capacity of your domestic bank.

....and, perhaps, a solar panel....wired to charge the leisure and cab battery...

Just as an aside, you say your power demands are modest, but I'm thinking your TV is awfully power hungry at 60W.
Looking on the back of our not exactly cutting edge 15 inch TV in the spare bedroom, it's half that at 30W.
Even our main 50 inch TV only draws 90W.
Al.

Mrgeoffrey wrote:Good stuff looks like you've sorted it by experimentation. 

The voltage drop between the inverter when wired through the cigar socket looks like it's where your problem is.

If it were me I would permanently wire the inverter to the battery with crimped on connections as close to the battery as you can sensibly get.(with a suitable fuse)

Also if you are intending to spend much time off grid you may need to look at increasing the capacity of your domestic bank.

Super - thanks Mrgeoffrey.

I have expanding this in another more appropriate trhead, but you are right, direct to battery makes perfect sense.

Rob

bikeralw wrote:Just as an aside, you say your power demands are modest, but I'm thinking your TV is awfully power hungry at 60W.
Looking on the back of our not exactly cutting edge 15 inch TV in the spare bedroom, it's half that at 30W.
Even our main 50 inch TV only draws 90W.
Al.

Hmmmmm, interesting.  When i saw 60w i was puzzled as thought they used a lot less as you imply.

I got the info off back of TV and might keeps eyes peeled for less hungry alternative!

Cheers!