Variable power from Batteries.

[nelson]

Hello there,

 

I am having trouble powering a laptop and 12volt TV.

Ive measured the output from the mains and Its a healthy 13 to 14 volts especially when the solar panel Is chucking out power.

however, when I run the appliances, the power drops to 11.5 ish volts. The baterries are only 6 months old.

When I run the engine the power Is fine but obviously I don't want to do that.

Any Ideas anybody? I would rather not use an electrician due to bad experiences, In my opinion of overcharging but shall If I have to.

Kind regards,

 

Nick.

 

[Mikexx]

9 minutes ago, nelson said:

I am having trouble powering a laptop and 12volt TV.

Ive measured the output from the mains and Its a healthy 13 to 14 volts especially when the solar panel Is chucking out power.

however, when I run the appliances, the power drops to 11.5 ish volts. The baterries are only 6 months old.

When I run the engine the power Is fine but obviously I don't want to do that.

Can you be a bit more specific about charging voltage? At 13V I wouldn't expect any charging, and at 14V it would take some time to reach fully charged, though fine for on mains or solar.

Is this 11.5V at the batteries or at your TV?

If at the batteries I would check connections and make sure they really are getting charged. Then you might have to consider another set?

[bizzard]

 It could be voltage drop in the wires to the telly and laptop. Wires too thin.

[Sir Nibble]

33 minutes ago, bizzard said:

 It could be voltage drop in the wires to the telly and laptop. Wires too thin.

Or a dirty fuse.

[Tony Brooks]

Please repeat your measurements at the battery and tell us the:-

Charging voltage from charger with solar covered or at night.

Ditto from alternator but at the end of a fair charging time and with the engine revving

Battery voltage about an hour after charging is stopped with no loads applied.

From that and you (presumably) readings from the outlet sockets you supplied above we have a good chance of telling you if its a charging, charger, or wiring fault.

 

[MtB]

6 hours ago, nelson said:

however, when I run the appliances, the power drops to 11.5 ish volts. The baterries are only 6 months old.

 

I'm with Bizzard on this. I think the chances are high the wires are too thin. Try measuring the voltage on the battery terminals when the power at the socket is 11.5v. If it is 12.5v this confirms the wires are too small.

Secondly, is this a new problem or has the telly never worked? I'm wondering if your new batteries have been consistently undercharged since you fitted them six months ago and have now finally died. 

[OldPeculier]

I had problems running a 12v/240v tv off the boat electrics. It didnt like any dips in voltage if the batteries were in anything but full charge.  The shower pump in particular would send it into stand-by.  I now run it in 240v mode through a cheap 300w inverter and have no problems.

[WotEver]

I don't believe it's voltage drop because OP states that it's ok with the engine running. I'm much more inclined to investigate the 'shagged batteries due to chronic under-charging' route. 

But the voltages requested will let us know in short order. 

[nicknorman]

43 minutes ago, WotEver said:

I don't believe it's voltage drop because OP states that it's ok with the engine running. I'm much more inclined to investigate the 'shagged batteries due to chronic under-charging' route. 

But the voltages requested will let us know in short order. 

I agree. Perhaps he should go back to the electrician who was good at overcharging, that might restore some battery life.

Although I suppose in a marginal case the slightly higher voltage from the alternator vs the solar might be enough to overcome wiring voltage drop, and/or there are poor connections at the battery with the services and alternator making a good connection to each other but not to the battery and the solar.

Anyway, more data needed to firm up a diagnosis.