Doubling Battery amps

So while we're on the subject, what is the difference??? ie +ve to +ve and vice versa ETC.

Thanks

Mark

+ to + and - to - is parallel

+ to - and other + & - to load is series

thats about it

Neil how did you so accurately measure the 2 x 12 volt 100ah batteries as only having 150ah?
Cheers Craig............

I was not able to cook bread unless there was full midday sun. Used to be able to cook any time of the day. Can only get to 12.5 to 12.8 volts with normal operation.
Also the Auto Electrician / solar expert measured the batteries and said I had about 150ah and explained why it was so. The batteries don't charge evenly so it is very slow to get the last 25% of each battery.
I have found that if I don't have anything drawing power (ie fridge) the batteries are now up to 13.5v after about 3 weeks.

parallel is less efficient than serial of higher amp batteries
but not by that much .. you have either a cruck battery or a
miesly solar regulator not taking advantage of the higher
voltage of a panel .. in theory parallel batteries add the amp/h
when discharged above C100 (100 hour discharge rate) ..
below C100 it depends on the characteristics of the batteries
and their condition/age.
In you case something is wrong but not the fact that they are parallel ..
I guess an el cheapo, uneffective solar regulator ...
good luck
gmd

>parallel is less efficient than serial of higher amp batteries

I have asked you to provide supporting evidence of this assertion on two (or is it three?) occasions now _gmd_pps – I am still waiting?

Mike Harding

do your own research ..
read up on a couple of dissertations from the MIT ..
have fun
gmd

Niel,
Will take longer to charge 12 volts to the same AH as 6 volts coz you are trying to charge more. If you have 12 volts 100AH battery, you need to charge at 12 volts, 10 amps per hour for 10 hours to charge a fully flat battery, ie 120watts for 10 hours. Now a 6 volt system, 100AH, you need to charge at 6 volts, 10 amps per hour for for 10 hours to charge, only 60watts. Therefore you are getting a bigger pump in to your battery for the six volts. Double your voltage, double your solar panels. On the other side, the highe rhte voltage of your appliances, the less amps they should draw to complete the job.
Regards
Ray

_gmd_pps:

A few weeks ago you engaged in a lengthy thread on this forum regarding the merits of batteries in parallel or series. You insulted Mike DiD and told him he didn’t know what he was talking about (he does), you gave us lengthy (albeit meaningless) diatribe based upon your own opinions of this series/parallel issue you insist exists.

At the time I asked you two or three times to provide references of sources to support your assertions – you may not know it but this is a perfectly normal practice in the scientific and engineering world, “because I say so” is not good enough – you ignored my requests.

I spent some time doing my own research and was not able to find a single source to support your personal theory. If your theory is correct then, given the proliferation of LA batteries across the planet, one would expect information to be readily available – especially from battery manufacturers – it isn’t

I have asked you again in this thread and you have refused – in your usual arrogant manner I might add.

I am compelled to conclude you are unable to support your theory.

Mike Harding

mike_harding@fastmail.fm

Mike could I be wrong but didn't he in that thread say to look at this US site about Avoiding parallel strings. I took note as I have 3 batterys in parallel and it was the first I had read this.
Wazza

Site Link

In telecommunications it is standard practice to run banks of 4 12V batteries in series to give 48V. You may then have a string of 20 lots of 4 X 12V in paralell to give a capacity of thousands of Amps It has been done this way for many many years with no problems.

Some interesting reading, including debunking some myths on parallel strings, can be found here ==> http://www.battcon.com/PapersFinal2002/McDowallPaper2002.pdf

Andrew

They cost money, :-)

Oops,

I meant to say power (watts) in the first paragraph

No matter what you do you will continue to have the similar power available ...............

Very clever. Do you understand it?

Cmon Garth,
You cant say that and not back it up..........
Ray ;-)

Thanks Mike,

Yes I understand it and have a piece of paper to prove it!!

It's alled an Asociate Diploma in Electrical Engineering.

4.5 years of three nights a week just so I can quote a set of laws written and discovered by some very smart people many years ago!

Now to really confuse everbody we could talk about "conventional current flow" and "electron flow". That would really throw the cat amongst the pidgeons.

Cheers
Garth

Garth - if you have a think about the type of people who use this Forum to gather practical information, you will find that your posts will be more useful if you focus on the practical applications rather than abstract theory.

Mike R

Mike,

Thanks for the reality check.
You're right. I quess I was attempting to have some fun and people who do know this stuff may get a chuckle.

I'm a bit gobsmacked when I read some of the comments from people who have "opinions" on subjects and use "facts" when I don't think they really know.

Having said that real world applications as oppossed to theory always does seem to work a lot better.

Cheers
Garth

Garth - I'm glad you didn't take my feedback the wrong way (it can happen very easily !).

There are still good reasons to state basic theory here - quite a few times here I have read things like "If you halve the voltage to a winch, then it will draw twice as much current - it's Ohms Law - P=I x V" !@#$$%!

Mike R

Spot on raunchy.

And two in parallel will supply the same voltage and the sum of the supply currents from each battery.

Refer to Kirchoff's laws above

LOL.

Cheers
Garth