Inverter install & battery life

[Gav Peter]

I'm slowly getting there with my third battery & inverter installation but I needed/wanted to get 240 in the truck for last weekend expidition around the Peak's/Derbyshire's finest lanes so I could run the carpooter with memory maps...

My buddy Rich cracked the GPS dongle that I had been struggling with very easily - how, I know not but was just delighted to finally see my locator flashing away on MM & following my every move to (seemingly) the inch...

Jumping ahead a wee bit, the system worked perfectly whilst we were out & about & I was able to navigate around the lanes that J66P passed onto me (Many thanks dude) on an overlay with great ease. The only problems occurring with me not knowing left from right at a few road junctions...

Anyhoo, the reason for the post... The inverter is one of Pauls 500w jobbies & the battery is one of Numax's 110Ah caravan batteries.

On the way back on Sunday evening, the pooter kept flicking on & off I suspected it was the battery & confirmed this when I got home as the inverter was bouncing out on low battery. I checked the voltage of the battery the next day & it dropped from 12v to around 10v quite quickly & that was where the low power setting started flicking in & out on the inverter...

Questions:

1. Is this normal?
2. Can the low voltage kick in be reduced on the inverter?
3. Should I just shut-up & get the battery wired into the charge system & stop whinging?

Va bene

 

[Jon Wildsmith]

Was the aux battery getting any charge? If not then that's about what you'd expect, that's a very inefficient way to power you carputer. What supply voltage does it need?

 

[Andrew Prince]

I needed/wanted to get 240 in the truck for last weekend expidition around the Peak's/Derbyshire's finest lanes so I could run the carpooter with memory maps...

Excuse my (electrical) ignorance but don't carputers, laptops and the like run off 12v? Wouldn't it be simpler to avoid transforming the current twice from 12v>240v>12v?

Sorry I'm not helping with your battery problems but you're probably drawing way more current than you need to to power your Cray supercomputer

 

[Gav Peter]

Was the aux battery getting any charge? If not then that's about what you'd expect, that's a very inefficient way to power you carputer. What supply voltage does it need?

Nope, it was lashed in for the weekend - no connection to the charging system - it really was the night before just to get the carpooter running. IIRC the Revo needs a 19v supply which I was using the inverter to supply via the 3-pin plug & transformer that comes with the pooter... The screen is a 12v thing but I was running that from the aux battery too.

Excuse my (electrical) ignorance but don't carputers, laptops and the like run off 12v? Wouldn't it be simpler to avoid transforming the current twice from 12v>240v>12v?

Sorry I'm not helping with your battery problems but you're probably drawing way more current than you need to to power your Cray supercomputer

Yeah, I obviously need to get some more work put into this - no problems with the battery, I just wondered if it was about right on draining it...

So what I need to get is a transformer/PSU to supply the pooter with its 19v from the 12v battery rather than use the inverter for 240 blah blah blah? Right? Right! Right!?!

 

[TonyP]

So what I need to get is a transformer/PSU to supply the pooter with its 19v from the 12v battery rather than use the inverter for 240 blah blah blah? Right? Right! Right!?!

If you look at my carputer thread I have the spec and the link to the PSU I used. There is also another one that Jon used which is similar

EDIT: This thread viewtopic.php?f=60&t=8322

 

[Gav Peter]

You were my next stop Tony

Cheers

EDIT: Blimey, thats a pricey little soandso isn't it???

 

[uHu]

If we do the maths:
A typical laptop, or a small, efficient pc with a small screen, would easily draw 60 to 70 watts. More if bigger. With the loss due to the (lack of) efficiency in one inverter and one power supply you would easily draw 120 watts. In 12 volt that would be 10 Amps.
A brand new, fully charged 100 Ah battery would last less than 10 hrs with that load. If the battery is 4-5 years old, and well maintained, it could have only 50 % left, i.e. 5 hrs.
Battery capacity specs are measured over 20 hrs, at a certain temperature. If you use all that capacity in less than 20 hrs, or at a lower temperature, it would be spent even faster than ampere times hours.

 

[Jon Wildsmith]

EDIT: Blimey, thats a pricey little soandso isn't it???

Are we looking at the same thing? Cheaper than an inverter!

 

[TonyP]

EDIT: Blimey, thats a pricey little soandso isn't it???

Yeah but that drives both the PC and the screen and does all the power management stuff, like turn on the PC on ignition on and also shut down the PC after x amount of mins on ignition off..... well worth the money in my view

 

[Gav Peter]

Are we looking at the same thing? Cheaper than an inverter!

Aye, those inverters from Paul were only £35

Yeah but that drives both the PC and the screen and does all the power management stuff, like turn on the PC on ignition on and also shut down the PC after x amount of mins on ignition off.....

I've no doubt its a splendid little PSU & if its what I need to improve the efficiency of my ickle system then it may be the future... The screen I bought came with a 12v lead with a ciggie lighter plug so I plan(ned) to run that directly off the aux battery in the final evolution of this install but I had always thought to use the inverter to power the pooter via its 240v lead...

Is there a PSU with less features for less wonka available then? In the end, it may be that the inverter becomes redundant eh!!!

Cheers

 

[TonyP]

Is there a PSU with less features for less wonka available then? In the end, it may be that the inverter becomes redundant eh!!!

Cheers

I am sure that there are..... but more expensive http://linitx.com/viewproduct.php?prodid=10917

 

[Rob]

Stop whining and get the battery wired into the charge system

Also the inverter is one of the most useful bits of kit I have, it is so useful in fact that I may replace my current hard wired 4 way extension lead to a 6 way one.

 

[Paul]

Right then......

And don't bombard me with pm's, but i may have few more for sale

including some mobitronic 600w

 

[Gav Peter]

Stop whining and get the battery wired into the charge system

Yeah, thats the next step After the whinge

 

[Jon Wildsmith]

Apart from testing, I have never had a use for my 2KW inverter, not in my 80 and not in my 100 What are you plugging in to all those sockets Rob? What am I missing out on

 

[Rob]

On my trip to Mongolia I was always charging something, needed to keep swapping the chargers around. Let me see there was my Nokia, my gfs phone, the sat phone, the laptop, 2 cameras, camping light charger, electric toothbrush, electric shaver... a lot of those things are old and need charging every day. I'm sure there was more.