HELP: Inverter is draining battery almost instantly! Why?

[spoon]

2. The crocodile clips are not going to give a secure enough low resistance connection to your battery and that can cause additional voltage drop under load that can make the situation worse. You can get an idea of whether this is a problem for you by measuring the voltage at the battery terminals (posts) themselves while the inverter is loaded and then measure the voltage at the inverter terminals at as close to the same time as possible. Then go back and measure at the battery posts.
A voltage drop of even a fraction of a volt will be costing you power and performance.

I had wondered this also, so I have removed the croc clips and put on one of the 'ring' style connectors straight to the terminal for a better contact.

I'm not sure if I can return the battery. I will contact supplier and see what the warranty status is.

In terms of appropriate replacement kit, I have no idea...

[Raul]

Hello soon
I would look into a victron blue solar charger ; they listed on eBay and you can get a 15a for 80 quid. It will work with your 250w panel and go for a Phoenix 350w inverter . You will not regret it.

[spoon]

Hello soon
I would look into a victron blue solar charger ; they listed on eBay and you can get a 15a for 80 quid. It will work with your 250w panel and go for a Phoenix 350w inverter . You will not regret it.

http://www.ebay.co.uk/itm/VICTRON-Charging-Controller-Energy-Blue-Solar-MPPT-75-15-for-12V-24V-/391043186260?hash=item5b0bfd7e54:g:-lYAAOSwm8VUy8Yc

This one^^

http://www.ebay.co.uk/itm/Victron-Phoenix-Pure-Sine-Wave-Power-Inverter-12v-350w-Boats-Caravan-Motorhome-/191542760666?hash=item2c98d694da:g:MBYAAOSwEeFVEF~p

And this^^

Doesn't look to me like the inverter has a standard (UK) 3 pin socet though, and standard power is 175w... (peak being 350w). Will that be enough?

[spoon]

Hello soon
I would look into a victron blue solar charger ; they listed on eBay and you can get a 15a for 80 quid. It will work with your 250w panel and go for a Phoenix 350w inverter . You will not regret it.

One more question, will this CC still be fine if I add another 250w panel of the same type to the system?

[Raul]

The CC in the link is the one but don't go for that seller , I did and got the wrong item . It took 3 weeks and no communication to get a refund as I sent the item back, bautech that is. Look fo listings in UK, there is a seller named meadow tech controls ; go on eBay shop and call the guy with your requirements . Highly recommended as he knows this stuff and can help you with design needs as well. If you order before 3 pm free next day delivery.
The inverter you linked is 175 you want a 350 so if you need more power in the future it will do the job; they very efficient inverters and very low stand by power draw .

[spoon]

The CC in the link is the one but don't go for that seller , I did and got the wrong item . It took 3 weeks and no communication to get a refund as I sent the item back, bautech that is. Look fo listings in UK, there is a seller named meadow tech controls ; go on eBay shop and call the guy with your requirements . Highly recommended as he knows this stuff and can help you with design needs as well. If you order before 3 pm free next day delivery.
The inverter you linked is 175 you want a 350 so if you need more power in the future it will do the job; they very efficient inverters and very low stand by power draw .

Brilliant, thanks. I've also contacted 12voltworld and asked what deal they can do on the pair. Do you know if, when in use, this inverter has a constant fan or one that only kicks in when temp gets high.

The one I have is quite annoying as the fan is on constantly on start up!

[lkruper]

One more question, will this CC still be fine if I add another 250w panel of the same type to the system?

Look at the blue table labeled Technical details, in the link for the CC on Ebay. Note the line:
Maximum PV power, 12V 200 W (MPPT range 15V to 75V)

Your panel is 250w. This CC goes up to 200w and the chart also shows 15A max. Take 250W / 12 = 20.8 amps. That is close to the theoretical limit to your panel and you probably will never see it. You may get 80% to 85%. You can measure that in bright sun with a volt ohmmeter that measures amps. But you can see that you need a charge controller that is rated higher to double the panels. But there is more. You need to decide whether to put your panels in parallel or series and make sure you don't exceed the voltage and amps that way as well. Don't jump into anything just yet.

As for the inverter, look at the specs on that page too. The self-consumption for that inverter is 2.2w. That will help you decide what drain it has on your battery as you use it. Also the efficiency. 87% if I remember correctly. Compare those figures to any other inverters you might consider.

[Raul]

Brilliant, thanks. I've also contacted 12voltworld and asked what deal they can do on the pair. Do you know if, when in use, this inverter has a constant fan or one that only kicks in when temp gets high.

The one I have is quite annoying as the fan is on constantly on start up!

The fan on that inverter only comes on when overloaded or near its max for long. It is whisper quiet . You may want to go for a 30a CC so you can add panels in the future if you need it

[LETitROLL]

One more question, will this CC still be fine if I add another 250w panel of the same type to the system?

The thing you want to make 100% sure of with that CC (I have one and love it) is that your solar input does not exceed 75V, it will use 200W @ 12v and 400W of input @ 24v (dictated by the battery), but you can hook up more with no problem, and actually some advantages in certain situations. If you are going to expand greatly I think you would want to look at other controllers, but at around the 400-500 watt gross panel total that CC is fine, considering you would probably be at 24v battery bank at that time anyway since 12v is kind of limited, and the nice thing about being overpaneled a little bit is more stable production throughout the day, you only get max production from solar for an hour or 2 per day around solar noon, the rest of the time it can be much lower, not to mention clouds, this way you can stay near max charging to battery bank (15A) for a large portion of the day. You can also buy a 2nd CC later and use 2 of these (30A total) if it ends up being cheaper than 1 large CC, and not have all your eggs in one basket (in case a failure, only half system down vs all with single CC), it mostly comes down to budget, there are many fine CC on the market in the $300+ price range, but this is the only one I have found for much, much less that has a pretty great reputation and performance Outback also has 2 new small ones, the 10A is slightly more $ than the Victron, and a 20A for quite a bit more, and I don't think they are customizable/adjustable? (the Victron is with optional usb cable).

[spoon]

Ok, lots to take in. I'm going to try and simplify what people are saying just so I make sure I get this right, as someone mentioned I don't want to rush into anything.

The linked CC will be fine with 1 more panel, same as I have now... But no more. I don't plan to go any higher than this anyway. That would need the panels to be linked in parallel though, so as to maintain 12v.

If I link 2 panels in series, I will need 24v worth of battery, yes? So the 2 numax's I have (provided they are fine). Giving a total of 220ah, 24v. Aaaand, the next step up in CC to cope with that. (30a).

I probably have a budget of around £250-£300 ($350 - $450)

[lkruper]

Your cc cannot use the power from 2 panels unless you have a 24v battery bank. That also means a new 24v inverter and also prob a charger for mains power.

[spoon]

Your cc cannot use the power from 2 panels unless you have a 24v battery bank. That also means a new 24v inverter and also prob a charger for mains power.

Oh. That sounds alot more expensive...

[LETitROLL]

It wouldnt hurt to check the Voc of your panel (not sure if that has been posted here yet), as long as it is less than 37V you would have the option of hooking up 2 panels in series, or parallel, if Voc is over 37V parallel only. Your selected battery bank voltage (12 or 24) is independent from the Panel voltage or wiring method (series/parallel), the CC will work fine either way, however in most cases it would not make good sense to hook up 2 panels of that size to a 12v battery bank, the CC will limit the input to 200W, in times of poor solar conditions (cloudy, sun low, etc.) it would make use of the extra panel, but during most of normal sunny days it would be a waste. Only with a 24V battery system can that CC Make use of 400W solar input.

[lkruper]

Oh. That sounds alot more expensive...

Solar/Battery systems are difficult to expand unless planned carefully, and even then there are limitations. If you think you will eventually add more items to be powered and/or want much longer run times for your devices then biting the bullet now and moving to 24v can save you money in the long run.

[LETitROLL]

Solar/Battery systems are difficult to expand unless planned carefully, and even then there are limitations. If you think you will eventually add more items to be powered and/or want much longer run times for your devices then biting the bullet now and moving to 24v can save you money in the long run.

+1, That is why it is so important to really come up with precise concrete numbers on expected loads, if you have that and your solar isolation for the area of use, it takes most of the guess work out and allows you to buy the correct stuff the first time.