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Batteries

PostPosted: Wed Oct 31, 2018 3:29 pm
by Hastings
Hi.
Looking online at battery prices, but Im having trouble identifying what is a reasonable warranty is for the money and more importantly, which company are actual manufactures if any, rather than a online reseller.
Are there any reputable brands that you all use/recommend?

Re: Batteries

PostPosted: Wed Oct 31, 2018 3:43 pm
by Gordon-Loomberah
If you are talking about Lithium batteries, they are almost all made in China, so unless you wish to import yourself, Oz resellers are the only way to get them.

I think there may still be some local Lead-acid battery manufacturers, so have a look at the manufacturers websites, although for a small quantity, it unlikely that you could buy directly from them.

If it is a DIY job, I doubt you will get any warranty on the name brand Li batteries, and may have trouble even getting them. Otherwise CALB or Winston cells are what most DIY'ers use.

Re: Batteries

PostPosted: Sat Nov 03, 2018 5:14 am
by Hastings
Where's that button, Gordon.......

Re: Batteries

PostPosted: Sat Nov 03, 2018 1:41 pm
by jules
In this thread you're dealing with batteries and in another, cable sizing but could I suggest that the most important and hopefully longest lasting items you'll need are a good charge controller and an equally excellent inverter. For an inverter I'd suggest either a Selectronics or Latronics 3KW unit. Both of these are Aus. made and very good units.

Many people here are fans of the Midnite solar MPPT CCs and they are undoubtedly a great unit. I use the rather more modest but very adjustable and extremely reliable Plasmatronics PL40 [Aus. made and with no fan noise]. I'm thinking of adding another PL40 to my system, rather than using a single larger capacity CC unit, partly because this would mean, that in the unlikely event of a regulator breakdown I would still have half a charge system [and the full battery bank of course]. From a DIY point of view, you'd be much safer working with a 24V system than a potentially max. 200V to 250V DC panel voltage system if DIY is your plan.

After you've set yourself up with this quality equipment you'll have next to no money left out of your budget :) but you won't need to change or upgrade your inverter or CC/voltage regulator, even if you add panels or change your batteries.

Don't let davidg see this :D but you could start off with second hand AGM batteries and replace them in few years at leisure. I've been using second hand lead-acid batteries for more years than I like to mention and as I've said here on a number of occasions, my first set were 35 years old when they gave up [case fracture rather than plate breakdown] and my current set [sorry, can't check their total age right now] are going strong at 5 years so they've been great value. Most of the time, when batteries fail, it's simply because they've been flogged repeatedly. If you're prepared to keep an eye on your DOD and stay within limits, even lead-acid batteries can last a long time.

Re: Batteries

PostPosted: Fri Nov 09, 2018 11:30 am
by Hastings
Thanks Jules, I think I'm a lot like you.

Re: Batteries

PostPosted: Fri Nov 09, 2018 7:58 pm
by davidg
jules wrote:IMany people here are fans of the Midnite solar MPPT CCs and they are undoubtedly a great unit. I use the rather more modest but very adjustable and extremely reliable Plasmatronics PL40 [Aus. made and with no fan noise]. I'm thinking of adding another PL40 to my system

PL40 is not MPPT and therefore quite a bit less efficient compared to a real (decent quality) MPPT charge controller.

jules wrote: From a DIY point of view, you'd be much safer working with a 24V system than a potentially max. 200V to 250V DC panel voltage system if DIY is your plan.

with a Classic 150V the typical VOC is generally just under the 120VDC limit (3 Panels, or it could be 2 panels)

jules wrote:Don't let davidg see this :D but you could start off with second hand AGM batteries and replace them in few years at leisure. I've been using second hand lead-acid batteries for more years than I like to mention and as I've said here on a number of occasions

Don't have an issue with 2nd hand batts/cells, but I know from direct experience you must be careful with the ones you get or it's just an utter waste of money.

Re: Batteries

PostPosted: Tue Nov 13, 2018 6:48 pm
by jules
It was slightly evil of me to have a go at you davidg, on batteries. I have great respect for your advice and the equipment you recommend. I also agree that 2nd hand batteries can be a gamble. For Hastings it could be worth contacting http://www.batrec.com/batrec as I've had good results with them. They might have retired though ... many years of experience.

quote davidg:

"PL40 is not MPPT and therefore quite a bit less efficient compared to a real (decent quality) MPPT charge controller."
and
"with a Classic 150V the typical VOC is generally just under the 120VDC limit (3 Panels, or it could be 2 panels)"

Cost of a Midnite classic, approx $1100. Cost of a PL40, approx $400. 1100-400=700. $700 = a lot of solar panels. 6 x 200W panels with a PL40 would cost less than 3 x 200W panels with a Midnite classic and in most situations the first combination would give better results.

Both the PL40 and the Midnight qualify as decent quality reliable pieces of equipment offering a good range of different settings options and storage of history.

quote Hastings:

"Thanks Jules, I think I'm a lot like you."

ha, I wouldn't wish that on anyone :D

Re: Batteries

PostPosted: Wed Nov 14, 2018 4:32 am
by davidg
jules wrote:Cost of a Midnite classic, approx $1100. Cost of a PL40, approx $400. 1100-400=700. $700 = a lot of solar panels. 6 x 200W panels with a PL40 would cost less than 3 x 200W panels with a Midnite classic and in most situations the first combination would give better results.

Both the PL40 and the Midnight qualify as decent quality reliable pieces of equipment offering a good range of different settings options and storage of history.

Lets assume 48Vdc nominal.

PL40 ignoring serious limitations in relation to voltage, 40A output so requiring at least 2 and quite possibly 3 to do the same job plus other extra bits to link them together. PL40 around 20% to 40% less efficient so requires more PV to get the similar results.

Midnite (only one brand) around 90A output from just one unit and can have approx 5kW's of PV connected no problem. can use upto 10 units linked together in follow me mode only requires "cat5 cable" to interconnect them.

Generally I would be installing about 5kW's of PV doing less seems such a waste, batteries typically get a full charge virtually every day on these smaller systems. Bigger system with auto generator, often there a fair bit more PV installed in which case with no automatic generator a midnite and an AC coupled inverter as well, between those that would using a Fronius linked into the SP-Pro, allows upto 15kws of PV. This combination works a treat, with an autostart generator generally I'd skip the DC coupled component and use a couple of Fronius or ABB's, however there are reasons one might still add an amount of DC coupled in for certain situations.

Also note Midnite's and Sp-pro's can programmed by computer so therefore remote management is perfectly feasible and remote monitoring is readily available for both units.

It's not just about cost. it's also about the end result and how well it works. Trying to save a few bucks at the expense of vastly reduce function is in the end actually wasting money.

If Plasmatronics had an MPPT product that had at least the same or better function to the Midnite and was cost similar I'd use it without hesitation, they don't, unfortunately. I'd much rather buy Australian particularly where there a better product compared to imported, even if it is a bit more expensive, provided there is decent backup repair service, "JIC".

# just saying

Re: Batteries

PostPosted: Wed Nov 14, 2018 7:38 am
by jules
The OP wants to install a system for $8k and I've taken that as central to designing his system. The systems you're suggesting, while excellent in many ways, go nowhere near that target.

I use a small system very successfully myself and I think there's still a place for these in solar world. It's quite possible to power washing machines, lights, computers, audio and power tools with a small systems, particularly in a small house, which is also where Hastings is coming from.

As to the 20% to 40% efficiency difference you suggest, I'm not going to get into an "is so", "is not" argument but the figures I get from my own system indicate nothing remotely approaching the inefficiency figures you suggest for a PL 40. Equally, I have had no signs of "serious limitations in relation to voltage" or any problems in relation to voltage.

Re: Batteries

PostPosted: Wed Nov 14, 2018 11:34 am
by davidg
jules wrote:The OP wants to install a system for $8k

??? I don't see than in any post in this thread.

So comparing a needed multiple pl40 based config to a midnite based config for about 5kW's.

Staying with only the DC charging parts and Ignoring the other parts of a system there would not be any real cost difference provided they were both properly installed without skipping the fuses/CB and other components.

I have had both PL40's and a couple midnite classics used them myself,there is no question the midnite is more efficient, over time a true MPPT charge controller is head and shoulders above one that's not. V limit for the PL40 100V max, Classic 150V, but not a hard limit, as I mentioned to an array of approx 5kW's multiple PL40's required and ensuring temp compensation is used a number of extra components required for a Plasmatronics arrangement, all parts required come with the a midnite including generator start plus an extra relay as well all builtin.