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UPS and Solar battery choice


Gabriël

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this thread is the sequel to the 'midpoint panic' thread.

to make a long story short it turns out one of my 250ah batteries is starting to die, the second one in less than 18 months, their name is on the enclosed spec sheet for those interested, they go for about 6k - you will note 5yr warranty...tch... you will also note different temperature compensations for float on the same document.... tch tch

now i sit with 3x123v 250ah batteries which are good, one which is dying and a dead one which i sold for scrap.

questions:

i want to provide an office with a 3kva ups, can i use my 3 good batteries for that purpose?

i believe i must replace the bank on my home 5kva system with a lithium ion unit. any suggestions?

God bless

g

beste sonic nps250 12 spec sheet.pdf

Edited by gabriel
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4 hours ago, gabriel said:

i want to provide an office with a 3kva ups, can i use my 3 good batteries for that purpose?

Yes, you can.

Only question is: 12v, 24v or 48v?

3 x 12v bank, or a spare battery for a 24v system, or buy another batt for 48v.

Only caveat, make sure the UPS does have oempf to charge to bank, check the amps it can push out via the charger.

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4 hours ago, gabriel said:

... any suggestions?

I would follow @Chris Hobson and @plonkster 's steps if I was you.

When my Trojan's go one day, either I go grid tied (still arguing with myself on that one) or what the then coolest tech bank at that point in time, here on the forum.

So at present, I am watching those two and their experiences, being very little, obviously means they are very happy with their banks.

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5 minutes ago, The Terrible Triplett said:

3 x 12v bank, or a spare battery for a 24v system, or buy another batt for 48v

i'll settle for 3x12v as that is what i have now. in fact if need be i'll go 2x12v and use the other good 12v250ah as a spare. re the capacity of the ups i'd appreciate your opinion, the draw will be max 3kw for max 3 to 4 hours - three pc's [and monitors] two printers, phone exchange, couple of lights. the bare necessities for a small office, the girls will have to to the boiling water etc on gas.

this thread actually belongs in the battery section, so an admin can move it; realized it too late :huh:

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Here is what I would think about.

You can get 1 x big 3000va UPS that has a charger to charge a 12v 500ah bank, but that is going expensive.

Or you could go for smaller 12v  1000VA inverters, one per battery, splitting the load = less wiring for you place them where they are needed. Jsut make sure they can handle 20-25 amps charging.

I have some 2400VA ones left over from Eskom days, but they are 24v. We used to put 2 x 200ah truck batteries on them.

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21 hours ago, gabriel said:

i believe i must replace the bank on my home 5kva system with a lithium ion unit. any suggestions?

Lithium Iron Phosphate, LFP or LiFePO4 :-) You can go Lithium-Ion if you really want to... then you need to look at the DIY PowerWall posts.

Suggestions?

Pylontech: around 16k for 2.4kwh (2kwh usable), or 32k for 4kwh.

FreedomWon: 30k for a 5kwh unit (4kwh usable). This is for their Lite-Mini model, has a locally developed BMS, not the Orion.

FreedomWon: 41k for a 4kwh. Lite-home model, has nice Orion BMS with inrush current limiting and external canbus/serial comms.

BlueNova, The Classic battery has a pretty similar price to the Lite-Home, though I'm not fully up to date with their pricing.

Mypower24/SolarMD, around 50k for their MSS 5.1 (5kwh usable).

So the cheapest option is the FreedomWon Lite-Mini. The cheapest option with a higher-end BMS is pylontech.

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Only time will tell how cost efficient the lithium batteries will turn out to be.

My only current, and which I can share, experience with the pylontech model is that they charge very quick, haven’t timed it, and don’t need attention.

I’ve got them running for six months now and they do their job in the background with no fuss. To date they have not run empty even with extended outages.

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16 hours ago, plonkster said:

Pylontech: around 16k for 2.4kwh (2kwh usable),

if i go down to bare necessities in power consumption during an outage and change bulbs etc - which might cost 2k max -  i have gas as well - then this seems the way to go. does it have its own bms or must i get a third party?

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30 minutes ago, gabriel said:

if i go down to bare necessities in power consumption during an outage and change bulbs etc - which might cost 2k max -  i have gas as well - then this seems the way to go. does it have its own bms or must i get a third party?

Pylon have their own BMS and Axperts are one of the approved inverters to be paired up with a Pylontech.

 

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Here's an idea for the office batteries and UPS. Why don't you save some lithium ion batteries from the land fill and build a DIY powerwall of about 100A using a 13s setup which is quite close to the 48v UPS battery charge/discharge voltages and use a BMS like Batrium . You could do that as practice for the main battery pack at the house.

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On 2018/07/11 at 3:17 PM, plonkster said:

Pylontech: around 16k for 2.4kwh (2kwh usable), or 32k for 4kwh.

  • that the one with the bms or bmu as they call it?
  • would that be with cables and brackets and vat? and
  • can i fit it myself?
  • will it run on my axpert 5kva

if yes to the above please pm me a phone number :D

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On 2018/07/11 at 3:17 PM, plonkster said:

Pylontech: around 16k for 2.4kwh

  • that the one with the bms or bmu as they call it?
  • would that be with cables and brackets and vat? and
  • can i fit it myself?
  • will it run on my axpert 5kva

if yes to the above please pm me a phone number :D

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1 hour ago, gabriel said:

that the one with the bms or bmu as they call it?

All the batteries I listed have a BMS (battery management system). The Pylontech one has a good BMS. A BMS does a few things, the most important one being that it disconnects the battery if there is a high cell or a low cell (conditions that can damage the battery). It will also monitor charge and discharge currents and disconnect if those go to high. Then it also balances the cells when a healthy voltage is reached, and finally (this is the bit you cannot do with an Axpert), it can communicate its needs to a sufficiently intelligent system and request the voltage and current it would like to operate at as well as communicate voltage, current and SoC levels (ie, the stuff the BMV does).

This comms bit is not supported by the FreedomWon lite-mini, but also not by your inverter.

For Pylontech, I'm led to believe that ICC supports reading the basic stuff (voltage, current, SoC) but obviously cannot do anything about it, just log it and act on the SOC.

1 hour ago, gabriel said:

would that be with cables and brackets and vat? and

I think Pylontech comes with cables, but it's a rack-mount form factor and you probably have to supply your own rack? @Chris Hobson will know. 32k was a thumb suck, but I did see it advertised for 14.5k ex vat recently so probably close enough.

1 hour ago, gabriel said:

can i fit it myself?

Yes. Well... probably, difficult to answer, some people shouldn't DIY, but I think you should be okay :-)

1 hour ago, gabriel said:

will it run on my axpert 5kva

Yes, I believe Chris said the Axpert is an approved inverter. Besides... if you mess it up, the BMS simply disconnects.

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50 minutes ago, plonkster said:

but I think you should be okay :-)

thanks for your trust in my 'skills' level :)

i take it that the lfp units are modular and that i can connect in series/parallel as time goes on and needs increase [read eskom declines], get more panels and another axpert [parallel] or bigger inverter etc?!

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31 minutes ago, plonkster said:

I think Pylontech comes with cables, but it's a rack-mount form factor and you probably have to supply your own rack? @Chris Hobson will know. 32k was a thumb suck, but I did see it advertised for 14.5k ex vat recently so probably close enough.

Each battery module comes with its own interconnect cables and communication cables. One has to order one cable pack per Pylontech stack (R295 VAT incl.). The modules are R14350 VAT incl.

The neatest way of installing them is inside a 19" server cabinet. A client of mine has made a rack using square tubing. Otherwise the is a bracket system for mounting 2 Pylontech modules which is a little over R400.

53 minutes ago, plonkster said:

Yes, I believe Chris said the Axpert is an approved inverter. Besides... if you mess it up, the BMS simply disconnects.

Jip both Infinisolars and Axperts are on the compatible inverter list. Victron, Goodwe, Studer and Imeon are also on the list.

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3 hours ago, Chris Hobson said:

Each battery module comes with its own interconnect cables and communication cables. One has to order one cable pack per Pylontech stack (R295 VAT incl.). The modules are R14350 VAT incl.

The neatest way of installing them is inside a 19" server cabinet. A client of mine has made a rack using square tubing. Otherwise the is a bracket system for mounting 2 Pylontech modules which is a little over R400.

Jip both Infinisolars and Axperts are on the compatible inverter list. Victron, Goodwe, Studer and Imeon are also on the list.

Just to add to this list Chris. The Mlt Oasis inverters and Nomad Mppt are also now Pylon Tech compatible.

Edited by LivSol
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On 2018/07/10 at 10:04 PM, The Terrible Triplett said:

You can get 1 x big 3000va UPS that has a charger to charge a 12v 500ah bank, but that is going expensive.

if i just use two 250ahx12v in series [keep the other one as spare and exchange now and then] the price should come way down as the batteries are the most expensive part of the ups... not? obviously i have to go with an on-line ups as it will have to go through the db and i'll have to compensate my sparky friend to do it which will cost a couple, but at least i know that eskom will not interrupt business.

do you guys think something like this might do the trick?

Edited by gabriel
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