6 minutes ago, plonkster said:

Oh, and for goodness sake... don't burn your house down. I've heard of two cases now via the grapevine of people playing with batteries getting into serious trouble.

Also, no hackery with BMSes. You can't use a Raspberry Pi running Linux to implement a makeshift BMS. Linux is pretty stable and all but not certified to never hang or crash. You probably know this, but I have to say it again for anyone reading this.

Don't burn down your friggin house!

 

Glad you only heard of two ……..   its daily occurrence ..  If you did not know, there is reason why you can only ship  lithium  by sea , there been at least 4 commercial aircraft (freight) brought down by lithium packs catching fire, there might be even more as freight aircraft crashed don't really make the media.

I've been selling Lithium   and using lithium batteries for about 9 years now .. Have fair understanding of limitations and safe working parameters (never 100% guarantee,  but i'm happy enough). The batteries will also be housed in my "power room" with the Lister and Victron inverters where if there is a fire, it cannot in theory spread to rest of the house.  

Re BMS/Linux:  That why I bought a Batrium BMS and it works plug and play with Victron..  Victron also will shutdown if no communication received for  1 minute (If I recall correctley) from any monitoring system (its own controller as well).

 

1 hour ago, ibiza said:

Hi, can you possibly share your source of the cells you use, or know for other places  where to get them?

Regards

Gumtree (pc recycling and 2nd hand pc/laptop guys)

 A few of the actual recycling companies will "sell" them as well, its easy money for them as they don' t need to actually recycle them.   Just be carefull of stupid prices some charge as you get about 50% of usable cells  only. I paid just bit more than what they would have gotten from recycling people (/kg).

 

18 minutes ago, Karman de Lange said:

If you did not know, there is reason why you can only ship  lithium  by sea

I know. Twice now I had to wait for my batteries to arrive (typically 6 weeks by sea) when the rest of the stuff arrived within 3 days :-)

20 minutes ago, Karman de Lange said:

Victron also will shutdown if no communication received for  1 minute (If I recall correctley) from any monitoring system (its own controller as well).

It literally has little countdown timers and when they hit zero the inverter goes into passhtru (if on grid) or turns off. There are different timeouts for different components. When using DVCC with a good BMS, the timeout is 5 minutes for any of the operational limit parameters (charge voltage and charge current). It is no substitute for a real contactor that opens when things go really bad... you're still expected to have one of those.

25 minutes ago, Karman de Lange said:

its own controller as well

If you're talking about the VEBus BMS, it is a lot faster than 1 minute. If you unplug the RJ-45 cable it goes into passthru almost immediately. I don't really have experience with the Vecan BMS (aka Lynx Ion, the one used with the HE batteries made by MG Energy Systems) so cannot comment on that.

13 minutes ago, plonkster said:

If you're talking about the VEBus BMS, it is a lot faster than 1 minute. If you unplug the RJ-45 cable it goes into passthru almost immediately. I don't really have experience with the Vecan BMS (aka Lynx Ion, the one used with the HE batteries made by MG Energy Systems) so cannot comment on that.

Was thinking of the CCGX .. I know the bus its few ms, tested that ones accidentley

Karman I've had my pack in service for about 9 months and I've had no hassles. No smoke no fire and the packs have stayed nicely in ballance with a variance of less than 0.08v across the 14 packs without a BMS. I really like to see the Batrium in action , have you installed it or is it on the way?

People come up with some pretty weird things. For example this one.

I have no idea why this guy opted to use the Victron busbars... they are pretty expensive components to use in an otherwise hacked-up system :-)

7 minutes ago, seant said:

Karman I've had my pack in service for about 9 months and I've had no hassles. No smoke no fire and the packs have stayed nicely in ballance with a variance of less than 0.08v across the 14 packs without a BMS. I really like to see the Batrium in action , have you installed it or is it on the way?

My issue is , I know how my life goes: "Yes, I will check battery's every week to make sure its balance" .. but that never happens, Its been in 2 days only and already forgot twice that I stuck charger on a cell to try get pack balanced .. ..  (My pack was not balanced before forcing it into production).

BMS on its way, ordered it yesterday only.   Hopefully it works as advertised .. 

What capacity average did you end up per cell, mine is about 1.7ah ?

 

 

2 minutes ago, Karman de Lange said:

What capacity average did you end up per cell, mine is about 1.7ah ?

 

 

That's about what I got 1.7 to 1.8Ah but I think averaged out closer to 1.7Ah. What did you use as cell holders? I had some made up but if I did it again I would redo the design.

If you want to balance the packs connect them all in parallel and leave them for a few hours. Then assemble the packs in series as required

20 minutes ago, seant said:

If you want to balance the packs connect them all in parallel and leave them for a few hours. Then assemble the packs in series as required

Plan was to just stick on my Revo balancer (8s) when I had time again,  but Eksdom forced me into production .. so i'm just doing in place balancing

26 minutes ago, seant said:

That's about what I got 1.7 to 1.8Ah but I think averaged out closer to 1.7Ah. What did you use as cell holders? I had some made up but if I did it again I would redo the design.

Just  hot glued them together , which is royal f-up.   … thats problem with having to rush things...   I thought of buying those 18650 holders, but works out rather expensive for piece of plastic, but def looks lot better.

Alrighty  then, time to expend the pack and order a Batrium BMS. I'm going to start charging batteries to build another pack of 100p modules . I will order some battery holders , so if anyone else wants let me know and then I can have them all machined at the same time.

Will it be worth my while to start up with 1 x Pylontech 2.4kwh battery or will that be a waste of time?

If I do start off with 1 module will it be better only to run it as backup, thereby losing my solar production?

I need to replace my batteries soon and I am looking at all my options.

The modules I refered to are made up of 18650 batteries and are connected in parallel , then each 3.7v module is connected in series to make up the required voltage 7s makes up a 24v pack and 14s makes a 48v pack.

If you are in a hurry then this is not your best option

1 hour ago, GVC said:

Will it be worth my while to start up with 1 x Pylontech 2.4kwh battery or will that be a waste of time?

If I do start off with 1 module will it be better only to run it as backup, thereby losing my solar production?

I need to replace my batteries soon and I am looking at all my options.

A single module only has 2Kwh usable energy, or 105W over 19 hour period. If you don't use the batteries much, i.e. it's not an offgrid installation, a single 2.4Kwh module would be fine just to power the inverter and offer a few hours backup at higher watts.  So it might be better to get more units if you can afford it / need more energy during the night. 

Got in Hemel!!!
I don't have the space for that let alone the time - That looks like it can power an Electric car for WEEKS!

Noice!

12 hours ago, GVC said:

Will it be worth my while to start up with 1 x Pylontech 2.4kwh battery or will that be a waste of time?

If I do start off with 1 module will it be better only to run it as backup, thereby losing my solar production?

I need to replace my batteries soon and I am looking at all my options.

I supplied @gabriel with one Pylontech module. He now has some practical experience  

1 hour ago, Chris Hobson said:

I supplied @gabriel with one Pylontech module. He now has some practical experience  

Nice

On 2018/08/19 at 10:52 AM, SilverNodashi said:

A single module only has 2Kwh usable energy, or 105W over 19 hour period.

as with all things battery this can only be achieved on paper... keep in mind you do not want a full discharge

13 hours ago, SilverNodashi said:

He now has some practical experience  

jip, my agms have been earmarked for another job [ups] and i have one pylontech us2000plus. with a base load of around 500w it will keep you going for at least 3 hours. i hope to get more units soon in order to be able to survive a night without candles and to utilize my pvs more effectively. i hardly ever use my full solar capacity during the day, charging four us2000 pylontech and using the stored energy for the greatest portion of the night will sort that one. it is quite an expensive operation but the ease of install, zero maintenance and efficiency together with the 5yr warranty gives peace of mind. don't forget the mass and space advantages!

as the wheels of bureaucracy turn slow the certification issues have not reached us with the same immediacy as with the coct guys, so my axpert is still acceptable on the west coast - i'll cross that bridge as and when necessary, in the meantime the budget has to make provision for batteries - remember that electricity tariffs will by necessity increase at least once more this year as far as i can see

1 hour ago, gabriel said:

as with all things battery this can only be achieved on paper... keep in mind you do not want a full discharge

That was calculated at 80% 

So with your 500W base load you'll have about 2 hours's standby, at 80%. Off course this varies, depending on what power is actually used by your appliances. 

Finally after a long time I ordered and recieved my Batrium BMS for my 14s pack . I ordered the expansion board, the shunt with the watchmon4. I battled to get it configured but then I found out that there was a newer software and firmware too. Now that it's running I have to say it a pleasure to work with and has some really handy configuration options. Like I can set it to turn the geyser when the pack is full , or switch on a cooling fan if the temperature is too high, or well just about anything you want really.  I should be getting my 5kva multiples II soon , then it's going to be like Christmas 😀😀

A very sensible combination - don't forget a Venus device is required.

Nice job !

I am looking for old laptop batteries, I have tested 1100 cells but still want more, lockdown is delaying my build as I have stuff in the post but I am still sourcing batteries, if anyone has a source let me know please

My first bank (32p14s) took me about 4 months to strip, pre-test, clean, charge, load-test, assemble and wired up... from old laptop batteries!  In April'20 after about 18 months, my 6th bank is installed and functional....

My powerwall currently is a (32×6)p 14s = 2688 cells  or in power >2ah x 32 x 6 x 50v = >19.2kw

(I hope to have the final 2 remaining banks operable by this year-end)