Attaching battery bank to inverter only

[Robere]

I have an Aims 5000 inverter with two separate connections (2 positive and two negative posts) for attaching batteries.

I currently have two 6 volt batteries attached in series for a 12 volt system attached to the inverter and fed by the charge controller attached to the solar panels.

Question: can I simply add a second set of two 6 volt batteries attached in series only to the inverter. If only attached to the inverter and not directly to the other batteries will they still be recharged by the charge controller attached to the first set of batteries? If yes, is this set-up as effective as attaching all four batteries in the more traditional manner (series and parallel combination) or is the connection through the inverter as effective?

It would be cleaner to attach simply through the inverter if this works as effectively.

merci/thank-you

[SunEagle]

I have an Aims 5000 inverter with two separate connections (2 positive and two negative posts) for attaching batteries.

I currently have two 6 volt batteries attached in series for a 12 volt system attached to the inverter and fed by the charge controller attached to the solar panels.

Question: can I simply add a second set of two 6 volt batteries attached in series only to the inverter. If only attached to the inverter and not directly to the other batteries will they still be recharged by the charge controller attached to the first set of batteries? If yes, is this set-up as effective as attaching all four batteries in the more traditional manner (series and parallel combination) or is the connection through the inverter as effective?

It would be cleaner to attach simply through the inverter if this works as effectively.

merci/thank-you

To be sure it would help if you provided a wiring diagram including wire size and lengths.

The safest and most efficient way to charge and discharge parallel sets of batteries is to have the batteries wire together and then a single pair of wires (+ & -) from the batteries to the inverter and another pair of wire from the battery system to the charge controller. Using the inverter as your "parallel wiring box" may introduce additional resistance and could cause an unbalanced charging circuit which can ruin a set of those batteries.

My other concern is the size of your batteries compared to that 5000 watt inverter. That seems pretty big unless your battery system is about 4000 Ah.

[Mike90250]

You are operating in Danger Land.

I would have to assume that the sets of terminals on the inverter ARE in parallel, and that in theory, you can connect battery and have it be charged via the inverter terminals. And I'm sure it's been done.

* Where are the fuses ?

* Batteries wired like this WILL end up being chronically undercharged, because of the double long wire leads

* Parallel terminals. This means the inverter mfg knows that 1 set of terminals is too small for the amps needed for a 4Kw 12v inverter (that's going to be about 350 amps) That's over 150a per wire set, IF they are identical. They aren't, and so one set will carry more amps than the other because of miniscule ohmic differences in all the connections. But miniscule ohms at huge amps creates a lot of heat.

Here at the smartgauge site, they cover the problems of parallel and ohmic differences quite well:

http://www.smartgauge.co.uk/batt_con.html

[juesus]

Thank for good info

[Sunking]

Great Balls of Fire. Another 5000 watt 12 volt Inverter. About 10 times too much power for 12 volts. BOOM! Here is what you get to look forward to.

[SunEagle]

Battery go boom

Sunking

I see you tried to jump-start your racing golf cart again.

[Willy T]

One thing for sure it wasn't caused by that cable carrying enough amps to do it. A better guess would be finger tight nut and bolt or a internal issue.

[inetdog]

One thing for sure it wasn't caused by that cable carrying enough amps to do it. A better guess would be finger tight nut and bolt or a internal issue.

And just why do you say that?
I agree that termination issues are more prevalent than wire size issues, but you can also have both at the same time.
Lead is not a really great conductor, so it is possible that the internal connections between the terminal and the plates played a role too. And lead has a much lower melting point!

[Willy T]

And just why do you say that?
I agree that termination issues are more prevalent than wire size issues, but you can also have both at the same time.
Lead is not a really great conductor, so it is possible that the internal connections between the terminal and the plates played a role too. And lead has a much lower melting point!

I say it because every failure I have seen where the wire is part of the fault at least the heat shrink has been burned off and usually the insulation. The wire appears to be no larger than # 4 awg. If the wire had been carrying very high amps un-fused to a 5000 watt load, I'd expect to see it.

[SunEagle]

I say it because every failure I have seen where the wire is part of the fault at least the heat shrink has been burned off and usually the insulation. The wire appears to be no larger than # 4 awg. If the wire had been carrying very high amps un-fused to a 5000 watt load, I'd expect to see it.

It does look like an internal failure as compared to a over loaded wire.

[almac]

It does look like an internal failure as compared to a over loaded wire.

i see some small burn marks on the nut where it contacts the ring connector. so it was a loose nut overheated , melted the lead