Haven't bought batteries yet - can I use a 12v car battery to test it?

[sunbelt57]

I plan on using the Classic Lite 150 with an Outback 48v with up to (30) 128 Watt panels hooked to (32) 6v golf cart batteries. I want to test it out with 4 panels (2 in series) using a 12 volt battery. I should be OK, right? As long as I don't hook up the inverter, of course, which is for 48v.

[zoneblue]

I plan on using the Classic Lite 150 with an Outback 48v with up to (30) 128 Watt panels hooked to (32) 6v golf cart batteries. I want to test it out with 4 panels (2 in series) using a 12 volt battery. I should be OK, right? As long as I don't hook up the inverter, of course, which is for 48v.

You can probably test it with any old rechargeable battery, with the usual precautions, eg max charge current, circuit protection, right setpoints etc.

Heck you could even the thing up with a bunch AAs i bet. Not to charge though.

BTW thats an awful lot of GC2s. Might you want to consider a bigger cell?

[sunbelt57]

The Sams Club near me only has the Optima batteries in 12v (marine) and they're > $200 so its cheaper to go with 6v even if I buy 1/2 the amount of batteries.

[sunbelt57]

I'm going to assume I can test it with a 12v battery WITHOUT any solar panels hooked up. (I'm doing this in my apt. living room). I've looked threw all the documentation and there's no mention of this.

[Vic]

sunbelt,

Yes,  if you just want to just check out and play with/become familiar with some of the functions on the Classic,  a small battery -- 12V -- should be fine.

Also,  you can use a Wall Plug-in power supply,  9 or 12 V at 100 ma or so should be fine as well,  for just playing around with the Classic,  and perhaps to Update the FW.   For this,  you will not need PVs.  And if you are running the wall plug-in transformer  you will NOT want PVs connected.

Vic

[TomW]

I'm going to assume I can test it with a 12v battery WITHOUT any solar panels hooked up. (I'm doing this in my apt. living room). I've looked threw all the documentation and there's no mention of this.

sunbelt57;

You certainly can set it up and fire it up from any battery above 12 volts. I used 2X 9 volts to upgrade one before I wired it in.

obviously it will not charge without a source but you can look at the menus, configure it, etc from any battery from 12 to 96 volts I think is the top end?

Good luck with it.

Tom

[Westbranch]

as ZB mentioned, that is a lot of batteries, it looks like you plan on 4 stings of 8 cells  (48V).  That many strings will be hard to keep in balance 

Better to start with 2 strings rather than murder  all 4  $$$  of them as you learn about how batteries work in real life.

[TomW]

as ZB mentioned, that is a lot of batteries, it looks like you plan on 4 stings of 8 cells  (48V).  That many strings will be hard to keep in balance 

Better to start with 2 strings rather than murder  all 4  $$$  of them as you learn about how batteries work in real life.

This is very good advice!

Most batteries are murdered by their owners not using them properly.

Fewer connections on the bank is better, too. Bigger individual batteries rather than multiple strings.

Just saying.

Tom

[sunbelt57]

I went ahead and used a 12v car battery (I also have a 12vdc wal-wart) and the firmware update went without a hitch. Thanks. I'm working on talking to it with local app (see my other posts). I found a diagram on how to wire 5 batteries in series. I wonder how that could be applied to 8. Seems that as long as I get all the batteries with the same mfg date and start using them all at once then the only problem would be the slight differences in the cable lengths.

[zoneblue]

I suggest you take a look in the archives at the NAWs forum, as this is a FAQ.

IF you MUST do parallel batterys we dont do it like your drawing. In order to allow the strengths and weaknesses of the cells to better "average out" you do full length strings with no mid string interconnects. You need a buses and equal length cables per string, and fusing per string. And keep an eye on the string balance from time to time.

Edit: that diagram is confusing, but its what it says:10 batterys in parallel. You must never do that!

[Vic]

sunbelt,

Here are some battery wiring diagrams:
http://www.smartgauge.co.uk/schems.html

Yes,  parallel strings,  especially for systems that are not Float-charged from the Grid are usually problematic.

Even it each battery was identical initially,  and all of the cables connecting each battery were identical,  batteries age differently in time,  and with cycling.  This will cause any initial balance to drift over a period of time.  If one tries to move batteries,  then to rebalance (this is difficult),  drift will continue.

AND,  a number of batteries spread out over an area,  can have different internal temperatures.  This also causes imbalance on charge and discharge.   Plus,   with many batteries,  it is difficult to know on which battery to place the Battery Temperature Sensor.  Having such a sensor on every charge source (or shared by all)  is very important to good battery health.

There are more factors involved,  but  determine the amount of battery that you need based on the loads the batteries need to serve,  then find how much energy needs to be returned to them for full charging --  from PV,  Grid,  Hydro,  Wind,  etc --  then you can go about designing the system.    The total power needed in a day or two,  and the peak power at any one time helps one know weather a 12,  24,  48 V (etc) battery bank will do the job.

If possible find  batteries that have enough AH capacity that can be provided from a SINGLE string.   Using a single string is not always practical,  but something to think about when you are designing a system.

Flooded batteries (ones with easily removable top caps) are a good bet for most systems.  They are less expensive than other types,  and have the advantage of being easily and inexpensively measured for State Of Charge (with your Hydrometer),  and will tolerate mistakes if those are noticed when you do your frequent battery check-up.

If you MUST use multiple parallel strings of batteries,  get a Clamp-On DC Ammeter,  and a good Digital MultiMeter,   and plan to monitor string balance fairly often,  and be prepared to try to move batteries around,  and/or perhaps charge/EQ separate strings as needed.   This takes time and dedication,  and diligence.

You may know this,  but just my read on things.   Have Fun,   Vic

[sunbelt57]

Yeah, I might want to rethink how many solar panels to put up and how much power I really need. Thanks.

[tecnodave]

Sunbelt57,

Are you Jason from kingman?    If so welcome to the forum. I had lost track of you but as I have said before, do your research first then buy. I'm glad you chose the Classic and outback over the Tracer and Go-power inverter. For your situation it is a much more cost effective solution.

On to batteries keep it simple!   Look at batteries with a larger capacity such as L-16's or 3050's
These are more approiate  for what you are trying to do.


I know that you have already bought SAMs club batteries so for now just buy enough to make complete strings, if I remember you said you had twelve so get 4 more and make 2 strings only of 8 6 volt "GC-2" golf cart batteries, DO NOT attempt four strings, it is simply asking for disaster, then you will have to start over.  Read here as much as you can and do visit NAWS forum as well as most of the DIY crowd gets the best info on these forums.

Gotta go but keep tuned , if you have more questions post here or email directly.

tecnodave

[sunbelt57]

No, I'm not Jason from Kingman. I guess that means I'm not welcome to the forum. Hey, experts, I was wondering if I could hook up (4) 12vdc powers supplies in series to make 48vdc. I was also wanting to break in my Outback inverter which is a VFX3648.

[tecnodave]

SunBelt57,

Please do not take offense, I council many newbies on solar. Jason's setup is way similar to yours and you both are in Arizona. My bad! I think that everybody is welcome here even if they bought brand X or Y! This forum is about sharing the knowledge that we have gained doing solar so hopefully you and others will not fall into the same problems that we have experienced doing solar. I see so much bad info on you tube that I do not even want to look there.


On the DC power supplies, it depends on the type,  Iota says yes you can, but some others will not divide the voltages correctly

On my system I use only Iota DLS-55/IQ4 chargers (12 volt 55 amp.) Most of my systems are 24 volt so I have wired a center of string tap so each Iota is "seeing a 12 volt battery" I.e. One does lower voltage stack 0-12v. And the other does high set. 12-24 volt.  I have power pole connectors on chargers so can swap out charger or loan it to 12 volt system. Only one spare required!

If you are trying to run inverter from DC power supplies as a test make sure that voltage total is not too high for the Outback.  Some "12 volt" power supplies are rated at 12 volt under load but put out some higher voltage when unloaded.  Read your Outback specs, it will specify maximum and minimum for the unit to work.

td