Tacet

Any suggestions as to good places to buy cables in Pretoria? I'll need to buy some 16 mm2, and I've seen some pretty wide-ranging pricing out there. Cheapest I've found online thus far is ARB at R2670 for a 100 m coil.

Does the Axpert then assume that all lithiums will have a range of ~10 V between float and cutoff? Taking a few 100 Ah blocks: The voltage range to the recommended cutoff can vary quite a bit. A pity the Axpert doesn't allow you to enter seperate values to use for SoC calculations.

https://www.soundselect.co.za/samson-srk12-12u-rack?gclid=EAIaIQobChMI2suXz9HD4QIVCbTtCh22bANQEAYYASABEgJaZPD_BwE

Any suggestions as to a rack for 19" lithium batteries? 12U should be sufficient for me - I'm very unlikely to ever buy more than about 3 x 50 Ah batteries. I am currently only planning on buying one battery, so the extra space is for upgrade purposes. I'd like something on lockable wheels, it just makes working easier once you have a few batteries in. I don't mind strengthening the rails myself to carry the weight. If this thing had a door I'd have bought it (if deep enough), but a door is sort of important too - the cabinet will be inside the house and will be accessible to kids.

This ESM 48100A1 was certified with an upper charging limit of 55 V. The recommended float voltage is 53.5 V. If 70 V work, good for you, but it's not something I'd do if I could avoid it. The 8 unit parallel limit is if you connect their BMSes with the RS485 interface. If you use the CAN interface you can connect up to 32 in parallel. The BMS limits the output current to 50 A. That means that a single battery can't give you more than about 2.5 kW output. You can get more by parallelling them, but be careful. At the very edge of capacity you'll reach a point where one of them disconnects because it is empty, throwing the whole of the load to the remaining one, which would then disconnect due to a overload condition. All should be fine, but I'd prefer to disconnect at e.g. 44.5 V when parallelling. As for the inverter and the battery's SoC - I wouldn't worry too much if the battery reads about 49.8 V on load.

I've stumbled onto this thread a bit late. Regarding the Huawei batteries: If they only give 3 kWh then there's something very wrong with them. New they should, from float to 44 V, last 118.8 minutes at a 50 A discharge current. That is 4.356 kWh. At the 80% end of life capacity, it should still give 3.48 kWh from a full charge. If that battery is in a good condition you shouldn't have issues getting 4 kWh out of it. It does sound as though these were discarded for a reason, or it was stored for a very long time without recharge. At temperatures below 30 deg C the recharge interval for storage is 12 months, for temperatures higher than 30 degC it is 8 months. What I don't like about them is that they have too many software functions. You can software limit the charge- and discharge currents, which may be what happened in your case. Huawei also have a software "lock" function which they offer the telco providers. The lock function will basically prohibit any discharge unless the battery is conencted to a rectifier paired to it.

Thanks @Krokkedil. That is basically the same concept as my blue pic, except that I don't plan to separate having any switched connection to Eskom in the DB. My peak load for general use is 6 kW. With a geyser timer and a bit of awareness I'll easily be able to manage my peak to remain within a 5 kW Axpert's limits. I'm the only one in the house which makes load management much easier. I'm assume that you're using VRLA batteries? I'll opt for LiFePO4, which is a bit easier to to handle in terms of fault current. Did you get a CoC for yours? I want to get a CoC after the installation, so as to keep the paperwork with the insurance up to date. As an aside - I'm also in PTA.

Bump on this one. I've been taking it slow, reading up more, looking at various inverter types and options. The cheapest for me will still the Axpert, but I want to make sure that I won't have issues getting a CoC once I have the system in. Connecting the AC directly to the Axpert would be ideal, but seems to open the whole debate of whether the internal bypass switch is acceptable under 10142-1. So currently I'm thinking of simply connecting both the output of the Axpert and the municipal supply to a transfer switch, and manually switching once the solar/batteries are down. That should avoid any compliance issues, as the municipal supply will be totally separated from the solar supply. However, I'd lose the ability of seemless switching, and I won't be able to charge the batteries from the municipal supply if I know loadshedding is coming and the SoC of the batteries are low. Any thoughts, comments?

Thanks, gents. I'll be careful of clones and rip-offs, then. 👍

I'm considering going the solar route. I dont' intend to go totally independent from Eskom, but to put up as much capacity as my roof can carry (about 3 kW, living in a duplex) and enough storage to cover a part of the night. My proposed setup is: Axpert MKS-5K 1 x Narada 48 V 50 Ah lithium battery 12 x 330 W Artsolar panels (they're out of stock, hopefully they get/make some soon!) I know that 2.5 kWh isn't much storage, but it should suffice for most of my needs. What's left can come from Eskom - it shouldn't be much. So questions: From browing these forums I know that there's debate regarding whether its internal transfer switch complies with SANS 60947-6-1. What is the standard solution to this: putting up an external transfer switch, or using the internal switch, hoping that we'll get clarity regarding its compliance soon (and that it does indeed comply!)? In perfect conditions I'll have more solar power than the inverter is specced for. Will it limit the incoming current, thus only using as much as it was specced for, or is the fact that I'll have 3.6 kW worth of panels on an inverter specced for 3 kW worth of panels a problem? Geewiz sells the MKS-5K. However, the pictures on their website looks pretty different from others places. Has anyone bought Axperts from them before? Do they provide the real deal, or a cheap rip-off? Thanks!