# 12v inverter recommendations



## stevegos (Jun 23, 2013)

Looking to buy an inverter. Mainly for wife's hair drying and also to run her food blender. 

Highest rated wattage is the blender at 1200w.

Now, most inverters have a nominal rating and peak rating. Can I assume the peak is what the inverter can deliver for a short period such as a few mins?

So I could get a 800w inverter with a peak of 1600w and that would cover it with some extra capacity? The blender would likely only run for 30 seconds or so.

Any recommendation would be great. Loads of cheap ones on ebay but not sure on quality.

All help greatly appreciated.

Steve


----------



## Sprinta (Sep 15, 2010)

just make a note to future-proof yourself, buy as high power you can justify as if you ever want to use a microwave oven then there is a start up spike of perhaps 50% on top of the rating of the unit. 

Therefore e.g. an 800w microwave may need 1000-1200w to start it and an inverter below that figure will not want to play.

I've got a 150w pure sine wave inverter for using the laptop, and a 2000w unit for nuking the food :roll:


----------



## Mrplodd (Mar 4, 2008)

A 1200 watt blender is going to pull some serious amps out of your battery so first off you need to make sure you have a decent amount of available leak sure battery capacity. I would think in terms of a a couple of 100+ AH as a minimum.

Edit...

For "leak sure" read leisure (don't you just hate auto spell correction on iPads??)


----------



## andrewball1000 (Oct 16, 2009)

If you weren't running your hair dryer or blender on full power I would recommend one of these on value and ease of return if it had a problem.

http://www.maplin.co.uk/p/maplin-12v-modified-sinewave-1000w-inverter-a12hq

I run a 1600w Hair dryer on 1kw but not on the full setting. I dont know about the blender.


----------



## Techno100 (May 8, 2010)

http://www.ebay.co.uk/itm/1000W-Pow...ervan_Caravan_Accessories&hash=item4aca082cbc


----------



## Mrplodd (Mar 4, 2008)

No need to lash out on a modified sine wave jobbie if all you are going to run is a hair dryer or blender. I have a standard cheappo inverter and it powers my HP NetBook without any problems at all, but the wriggly amps do go through a charger/mains supply unit before actually getting to the NetBook. however I am aware that some laptops/net books etc can be a bit "choosy" about such things.


----------



## Techno100 (May 8, 2010)

You could watch this, one went for £98 yesterday
http://www.ebay.co.uk/itm/Quasi-Sin...tEquipment_Accessories_SM&hash=item4ad006be3a


----------



## stevegos (Jun 23, 2013)

Can I assume that a 1000w inverter running a 100w items will only draw 100w or similar from the battery?

And when it says peak power, this how long can it typically delivery the peak power? Just a few seconds or minutes?


----------



## VanFlair (Nov 21, 2009)

The modified sine wave are the cheapo's, the expensive ones are the pure sine wave, just check that what you want to run will be happy on the modified sine wave.

We have the Merlin M power pure sine 2kw with wired remote start stop panel, not cheap but runs things with fussy electronics in that simply won't run on the modified sine waves.

Martin


----------



## Techno100 (May 8, 2010)

Mine has not yet failed to satisfy anything

http://www.sterling-power.com/products-230vi-quasi.htm


----------



## Techno100 (May 8, 2010)

I've been watching inverters lately and this has come up since yesterday. Best price I could find anywhere was £310
Today £178 8O 
1600 watt pure sine with 8mm studs so you can fit your own cable
http://www.batterymegastore.co.uk/product/SIB121600/

Cheapest on ebay £322
http://www.ebay.co.uk/itm/Sterling-...tEquipment_Accessories_SM&hash=item27cfc84975


----------



## VanFlair (Nov 21, 2009)

Techno100 said:


> I've been watching inverters lately and this has come up since yesterday. Best price I could find anywhere was £310
> Today £178 8O
> 1600 watt pure sine with 8mm studs so you can fit your own cable
> http://www.batterymegastore.co.uk/product/SIB121600/
> ...


Looks like a good price our Merlin 2kw was £700.

Martin


----------



## midgeteler (Jul 19, 2009)

I have ruined 2 toothbrushes charging with a cheap Ring inverter.
Do they require pure sine wave charging?

Luckily they were replaced under guarantee. There was nothing to warn of this in the user guide.


----------



## VanFlair (Nov 21, 2009)

Techno100 said:


> Mine has not yet failed to satisfy anything
> 
> http://www.sterling-power.com/products-230vi-quasi.htm


I am sure that the quality of the modified wave will have something to do with performance but when our van had the old modified inverter in the microwave made all the right noises but failed to perform, and the Nespresso coffee machine would warm up but not actually deliver coffee it did specifically say in the manual NOT to be used in motorhomes or words to that effect.

Martin


----------



## Techno100 (May 8, 2010)

My microwave as installed in this Starspirit loved the Pro power no problems
http://www.motorhomefacts.com/ftopict-105051-.html


----------



## DABurleigh (May 9, 2005)

midgeteler said:


> I have ruined 2 toothbrushes charging with a cheap Ring inverter.
> Do they require pure sine wave charging?
> 
> Luckily they were replaced under guarantee. There was nothing to warn of this in the user guide.


John,

Yes. See the MHF inverter guide:
http://www.motorhomefacts.com/ftopic-65101-0-days0-orderasc-.html

Dave


----------



## listerdiesel (Aug 3, 2012)

What affects the gadgets and the inverters is the type of load they present to the inverter output.

Resistive loads like incandescent lighting are no problem for all types of inverters, but anything with an inductive content like a motor or a flourescent ballast will case the cheap ones problems.

It is down to the power factor of the load, expressed in a decimal figure between one (unity) and zero. Purely resistive loads are Unity power factor as there is no reactive content. As the inductive/reactive increases, the power factor figure falls, mains flourescents are about 0.6.

The higher the power factor, the more inverters will run it.

Loads like hairdryers with mixed power factors are usually OK as the power factor of one for the heater element helps the low power factor of the motor, which by itself may be 0.6 or 0.7, but the two parts combined are up around 0.8 - 0.9.

Switching power supplies can take pretty rough AC with no problems, but some small gadgets will fail to run on a quasi-sine wave inverter as they need the sine wave to be as pure as possible for their own functioning. 

Some electric tooth brushes have the transformer for the charger in two parts, one is in the base plugged into the mains, the other is in the handle that plugs onto the base. It is the magnetic coupling between the two parts that makes it work.

Peak power ratings are always a bit suspect as they are rarely defined, so in my own case I look for what I need plus 100%, ignoring 'peak value' figures quoted in the adverts.

If you need 1200W, go for a least 2kW (It should be kVA not kW as it is AC output) or more. The peak power rating is meaningless unless accompanied by the DIN standard table of duty cycle operation.

Sorry if that's a bit long.

Peter


----------



## midgeteler (Jul 19, 2009)

DABurleigh said:


> midgeteler said:
> 
> 
> > I have ruined 2 toothbrushes charging with a cheap Ring inverter.
> ...


Thanks for that Dave, I read most of your splendid offerings, but must have missed that one.
Another quick one if I may--I have heeded the advice given by many here concerning the mixing of different types of batteries when forming a bank. What are the perils of doing this?
The leisure batteries are normally of the sealed type, but the vehicle (engine) one is normally vented. Why the caution?


----------



## listerdiesel (Aug 3, 2012)

It is the battery condition that is more important than the capacity.

Two good batteries in good condition will co-exist in parallel without any issue.

They must both be of the same type, ie vented or sealed, and preferably of the same make if possible.

It is not an ideal situation, but no harm will come from it and it saves ditching a good battery.

Peter


----------



## stevegos (Jun 23, 2013)

Ok, thanks for all your advice and recommendations.

Its seems to me the best idea is to get a 1500w modified sine wave type inverter for the high demand items (like the blender and hair dryer) that should not be as fussy about the voltage condition and if needed a smaller 200w pure sine wave inverter for those that need the cleaner AC.

Does that sound like a good idea?


----------



## rayrecrok (Nov 21, 2008)

Hey up.


Get the biggest you can fit or afford.. any inverter takes out of your leisure batteries what it needs to run whatever your are using.

It is a red herring when someone says a big inverter flattens the battery. What ever you are running flattens your battery. Just turn it on to fire up your gadget, then turn it off when you have done and all will be well.


----------



## DABurleigh (May 9, 2005)

Just that inverters get increasingly less efficient below 50% of their rated output, that all. There is no cliff-edge disaster. Again, this is mentioned in the MHF inverter guide. 

Dave


----------



## chromedog (Feb 10, 2014)

*inverters*

Buy best you can afford. Quasi-sinewave or modified sinewave or the cheapo non sine wave ones are HASSLE,, and could do damage to some of you equipment... SO get a PURE- sinewave model and make sure it comes with a remote control .. as you are best fitting it as near as possible to the battery, and if that's under the bed or in an outside locker ,,, more hassle turning it on and off....

note as a fool proof way of connection make up a power cable that has a plug on one end to fit the inverter, and a standard blue hook-up plug on the other, then if you want to use the inverter ,, unplug the main hook-up and pop in the one from the inverter, that way it is imposable to have the mains on and the inverter on at the same time (if you do untold damage will be the result and much sparking....)


----------



## rayrecrok (Nov 21, 2008)

*Re: inverters*



chromedog said:


> Buy best you can afford. Quasi-sinewave or modified sinewave or the cheapo non sine wave ones are HASSLE,, and could do damage to some of you equipment... SO get a PURE- sinewave model and make sure it comes with a remote control .. as you are best fitting it as near as possible to the battery, and if that's under the bed or in an outside locker ,,, more hassle turning it on and off....
> 
> note as a fool proof way of connection make up a power cable that has a plug on one end to fit the inverter, and a standard blue hook-up plug on the other, then if you want to use the inverter ,, unplug the main hook-up and pop in the one from the inverter, that way it is imposable to have the mains on and the inverter on at the same time (if you do untold damage will be the result and much sparking....)


Hey up.

You are right with pure sine wave, but they are very expensive.

I have run a 3000 watt ring modified sine wave, which I take off my old vans and put on the current one for quite a few years now without any problems, it runs anything and everything except the microwave which is 800 watt without any problems what so ever, the lap top, telly, the lot.

Ray


----------



## Techno100 (May 8, 2010)

I guess eveyone missed my link then?
1600 watt Sterling pure sine £178.50 that's cheaper than Sterling Quasi sine


----------



## DABurleigh (May 9, 2005)

midgeteler said:


> Another quick one if I may--I have heeded the advice given by many here concerning the mixing of different types of batteries when forming a bank. What are the perils of doing this?
> The leisure batteries are normally of the sealed type, but the vehicle (engine) one is normally vented. Why the caution?


John,

It is quoted as a mantra, but as usual, things are more subtle.

Let's take a situation where two 12V batteries are side-by-side. They are very different - one is brand new, smaller capacity, flooded, traction, has separators between the plates, Brand X; the other 4 years old, large capacity, gel, leisure, no separators, deep discharged many times, a bit sulphated and Brand Y. They can be the same rough % state of charge.

They are connected together in parallel and to a charger. The charger has absolutely no clue about the batteries - it is simply following Ohm's Law, which regulates the charging current in accordance with the total battery resistance it sees. The problem is that a battery's internal resistance changes a lot during both the charge and discharge cycle, and how it changes is dictated by its design/construction, manufacturing, age, number of cycles, whether it has been abused, etc. So at any point of the charge/discharge cycle, the internal resistances of these batteries can be very different, and this means the charging current through them is equally different. So each battery is significantly affecting the charging of the other, to its detriment from that intended. This can significantly degrade the residual life of BOTH batteries.

Thus, in an ideal world, you would buy two identical batteries at the same time from the same place to minimise these batteries and ensure things start off 'matched' and stay matched for as long as possible.

Let's take a different situation of a vehicle and a motorhome 'house' battery, both charged by the alternator. Now, the alternator will be sensing the vehicle battery, between which there is very little cable resistance. The alternator will in any case not charge above the 14.4V gassing voltage. The 'house' battery will be further away, and often with not the thickness of cable you would like. The charging voltage at the house battery will be less, because of the resistance. In this situation, any mismatch between the batteries is being dominated by the effect of the resistance to the second battery. A far bigger concern in practice is then that the 'house' battery seeming to take ages to charge while driving. In such a situation, I really don't care that the batteries are different.

Dave


----------



## midgeteler (Jul 19, 2009)

I see, so in an ideal world, it would be preferable to keep the charging of the Hab batteries separate from the traction battery in order to lengthen their respective lives? and you wouldn't recommend B to B chargers?
I ask due to upping my solar power and considering separating the system so that the bats supplying the invertor are only charged by solar or ehu. It was recommended to me that it would be advisable to fit BtoB in order to put excess charging current from the Hab bank to the invertor bank. 

All the batts are Aqualine sealed, 2x125/2x105 bought in pairs at the same time, after suffering a short life span (3 years) with Elecsol 110.


----------



## listerdiesel (Aug 3, 2012)

I think some of these 'solutions' are looking for a 'problem' to solve.

Keep it nice and simple (he says, with a duel solar panel/controller!)

If you can keep Hab and Vehicle batteries separate, that does give you better protection against coming out one morning and finding the vehicle won't start.

We split ours up for different reasons, we have a winch and the engine room lighting on one system, which is kept running with its own solar panel and mains charger.

IF I had a motorhome, I'd definitely keep to the split system if I needed separate charging for the vehicle battery, but the best option really is to have a big solar array for the Hab batteries and leave the vehicle system on its own.

BtoB do a job, but I often wonder how many people actually need it when touring, and a small charger on mains at home would do the job of keeping it all healthy when not travelling. 

Peter


----------



## midgeteler (Jul 19, 2009)

listerdiesel said:


> I think some of these 'solutions' are looking for a 'problem' to solve.
> 
> Keep it nice and simple (he says, with a duel solar panel/controller!)
> 
> ...


Hi Peter, to complicate things a little more--- The MH sits in a garage in the winter which has a solar panel on the roof, which I plug into the regulator to keep the batts up. Works ok.

ps: this is the 24v panel that we spoke about some time ago!


----------



## Techno100 (May 8, 2010)

Techno100 said:


> I guess eveyone missed my link then?
> 1600 watt Sterling pure sine £178.50 that's cheaper than Sterling Quasi sine


They got the price wrong and removed the link and took the 1600watt off altogether.


----------



## stevegos (Jun 23, 2013)

:x NOT IMPRESSED WITH WWW.BATTERYMEGASTORE.CO.UK :x

Techno100 had kindly posted a link to the Stirling Inverter a few days ago.

I phoned batterymegastore.co.uk and asked about the spec as there was very little info on the web site. Immediately after the phone call I ordered the product online and they had put the price up to £322.96 from £178.50.

They must have realised their mistake. I phoned and spoke to Paul. They certainly were not interested in taking responsibility for their mistake, not even apologetic. We cannot sell it at the advertised price. We will do you a special price. I'll phone you back with the price.

I waited and waited. After 5 hours Paul had not bothered to call back. I phoned them back... £20 off the normal price. Whats the normal price? Its £288.95 So now another different price than the web site! I have other items to buy and my total budget does not cover the extra £88 so I declined. But it was still a good price!

I wasn't just going to buy the inverter but a handful of other high value items. Now they have just pi**ed me off and I will take my business elsewhere.

No responsibility, No customer service, NOT IMPRESSED.


----------



## Techno100 (May 8, 2010)

I agree [email protected]


----------



## stevegos (Jun 23, 2013)

I've now realised the price they gave me was for the quasi-sine and not for the pure-sine so they also got that wrong.


----------



## DABurleigh (May 9, 2005)

midgeteler said:


> I see, so in an ideal world, it would be preferable to keep the charging of the Hab batteries separate from the traction battery in order to lengthen their respective lives? and you wouldn't recommend B to B chargers?
> I ask due to upping my solar power and considering separating the system so that the bats supplying the invertor are only charged by solar or ehu. It was recommended to me that it would be advisable to fit BtoB in order to put excess charging current from the Hab bank to the invertor bank.
> 
> All the batts are Aqualine sealed, 2x125/2x105 bought in pairs at the same time, after suffering a short life span (3 years) with Elecsol 110.


The traction battery usually IS the Hab battery. In an ideal world, yes, but in practical terms, there isn't much wrong with a bog standard split-charge relay BUT with decent cables (again, practically, it is easier doubling up on cable than using a single thicker one).

As to B2Bs, I think they have utility in overcoming the shortcomings of thin cabling, but therefore can be a bit of a sledgehammer to crack a nut. With decent cabling, I think they only have a real utility in a minority of motorhome uses - such as winter touring without hookup and only going short distances between stops.

I'm waiting impatiently for CHP LPG fuel cells and resistance wires to cope with all MH space & water heating, cooking (and battery charging). It's been a long wait so far :-(

Dave


----------



## midgeteler (Jul 19, 2009)

That's basically what we use our 'bus for Dave, so maybe worth a punt for us.
I did follow your piece on fuel cells, but thought it had died a death as there has not been any interest shown commercially for a while.


----------

