Inverter issue

Scotchgitt

Free Member
Apr 24, 2019
3
0
Funster No
60,165
MH
Van conversion
Exp
3 years
I have a 2000w sine wave inverter. 4000peak

When I turn on my coffee pod machine 1300w the low voltage trips

I have 2 210ah batteries in parallel and it still trips. Sits at 12.4 v with no load then drops below 10.7 low voltage.

Batteries are healthy and fully charged

When I run the engine and the voltage sits at 13.5v it works fine.

Can I fool the low voltage so I don’t have to run the engine?

Do I build a 2v lithium cell to add in series to compensate?

I used to use a cheap non sine wave and it all worked ok until the inverter stopped working.



Thanks
 
Apr 28, 2010
2,030
2,642
St Albans
Funster No
11,285
MH
Winnebago Sightseer 31E
Exp
8yrs, but many years a tugger.
Batteries phutttt. 12.4v is not fully charged. 1300w would be a challenge for healthy fully charged batteries. :gum:
 
Last edited:

funflair

LIFE MEMBER
Dec 11, 2013
11,719
11,168
Guisborough
Funster No
29,351
MH
N&B Flair 8000 IVECO
Exp
since 2012
I agree that the batteries might not be in the best of health, also how far away is the inverter from the batteries and what size cable? when we first got our van it similar issues but that was caused by close to 8 metres of cable between batteries and inverter.

Martin
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
18,962
18,687
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
Since 2008 & many years tugging
Maybe your cables to the inverter are too small, if the cables aren't up to it you will get a volt drop across them.
What size are your cables?

At the very minium I would think you need 35 mm sq cables.
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
18,962
18,687
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
Since 2008 & many years tugging
Sits at 12.4 v with no load then drops below 10.7 low voltage.

Batteries are healthy and fully charged
No way are the batteries are healthy and fully charged at that voltage, fully charged they should be an absolute min of 12.7 normally on a good battery 12.8 to 13.2v.
 
May 7, 2016
1,602
1,113
Poole, Dorset
Funster No
42,951
MH
Carthago Compactline
Exp
Since 2003
As batteries age they can lose capacity through sulphation. Basically this clogs up parts of the plates, leaving a small area to do all the work. This means that a battery that started off life as 100Ah might be performing at say a 30Ah level. The bit that is working may still charge up to the usual voltage and appear healthy until you ask too much of it. Think of it like a toilet cistern full of bricks, it will fill up and appear full but won’t flush the toilet properly.
 

Zigisla

LIFE MEMBER
Oct 24, 2015
2,231
2,498
Fareham, Hants
Funster No
39,738
MH
Sunlight A72
Exp
Getting better month by month.
I had the same thing on my first set of batteries. Sat at 12.6v thinking they were fine until you switched any load on, then they dropped. Switch on the inverter and they plummeted and tripped the low voltage cct off. Replaced batteries and all was well - for 18 months anyway.:rolleyes::rolleyes:
 
OP
S

Scotchgitt

Free Member
Apr 24, 2019
3
0
Funster No
60,165
MH
Van conversion
Exp
3 years
Thanks for the replies.

I will do some more research. They are solar charge only and the solar charge control box is saying they are full.

I will dig out the multi meter.

I have a split charge relay to fit so it will charge when I’m driving and the inverter has a built in charger so once I have tested the before voltage I can do some experimenting.

I have new solar panels and controller on my todo list all ready to fit

The inverter is 500mm away from the battery.
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
18,962
18,687
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
Since 2008 & many years tugging
I will do some more research. They are solar charge only and the solar charge control box is saying they are full.
If the solar is connected you will be reading the solar regulator voltage not the battery. To get an idea of the battery voltage you need to disconnect the solar, or cover the panels, or do it at night. Let the batteries settle for an hour before taking a reading.
 
Last edited:

funflair

LIFE MEMBER
Dec 11, 2013
11,719
11,168
Guisborough
Funster No
29,351
MH
N&B Flair 8000 IVECO
Exp
since 2012
If your batteries are no 12.7 a couple of hours after the sun goes down they were not fully charged.

Martin
 
SMC Motorhomes Newark
RoadPro
Johns Cross
Safeguard Motorhome Insurance
Rhino Installs
Friendly professional service from qualified technicians
Free Club Stickers
Dave Newell Leisure Vehicle Services
Top