Jankzilla

Curious to see how the Revo stacks up against SunSynk/Deye in hardware and software.

Thanks @P1000, How embarrassing. I assure you I have been reading the manual, but I missed that. Thanks very much. To be fair, my manual is different and the info is a little italic line, not a table. Need to read the fine print! Is there any harm in using 32A breakers if it’s connected to a 20A circuit? I was thinking that might be a bad idea but presumably the 20A DB breaker would protect the cable leading to the inverter if there was a problem? I’m going to try to limit the current in the settings. Just wondering if I ought to spec the inverter’s AC breakers down until I can run thicker cable. My impression is that 3 prong plugs are only 16A so my inclination is to put 16A breakers on the inverter side in the mean time. JZ

Don’t forget you need to know how much power those PoE switches are using. If you want to save some money, I would recommend buying a kill-a-watt for R400-R500 and conducting an energy audit. Figure out how much power you are actually using. For example, one of my computers has a 750W power supply, but it only uses about 250W most of the time. If I based my spec on 750W I would end up buying a battery 3x larger than I need, and the batteries tend to be the most expensive part of any such build. Once you know how much concurrent power you need in watts, multiply that by the number of hours you need it for. So say it’s 1000W and you need it for 4.5hrs, that’s 4500Wh or watt hours (aka 4.5kWh). I would add a good 20-30% on top for safety and efficiency losses. Also consider the difference between how much you’re actually using and how much you could theoretically use. Computers use way more power starting up or shutting down for instance. Your 1000W system might pull 2000-3000W at peak, so make sure to size the inverter accordingly. I recently did the calculations for Stage 6 myself. It gets a little bit complicated if you are trying to work out the minimum requirement. If you are going off worst-case (ie a full 4.5hr outage instead of 4.1hr or whatever) and you need it to always stay on, you need to figure out the weird parts of the schedule. Particularly where one day ends and the next begins. For example, you will usually have at least 4.5hrs between outages, but every few days (where I live) we get a 4.5hr outage either 2.5hrs before or after a 2.5hr outage. So you have to figure that you either need to be able to recover for or from a 4.5hr outage within 2.5hrs. One method is to get batteries that can charge that fast (honestly most rackmount batteries can do 0.5C which means that they can be charged in 2hrs with a sufficiently powerful charger/hybrid inverter) or to get enough headroom that whether you have 2.5hrs, 4.5hrs or whatever, you aren’t going to be so close to the line that you need to worry. The latter is the more expensive option clearly. Note that most rackmount batteries are 48V, I think the Pylontech UP2500 is a notable 24V exception. Also note that some non-rackmount inverters frequently get placed on their back in a rackmount configuration but that isn’t really ideal as they are designed to be vertical for cooling purposes. If you are going to mount them in this configuration, make sure the room has adequate cooling.

I am in a similar boat. I think the Smart Power Systems SPS-1000 was the only LFP trolley I could find which actually listed the noise level on the spec sheet, they claim 40dB. Having stated it I don’t see any reason to doubt it. I think the Schneider 700W inverter is silent too, but it may not be powerful enough for your needs. Also don’t quote me on that. There are mixed reports of various “Mecer trolleys” which are silent or sound like jet engines. Seems like a bit of a lottery. It may be helpful to check out some options in person if that is available to you, but even then, noise can be incredibly deceptive. A trolley which seems completely silent on a showroom floor could be incredibly annoying in the silent quietude of your abode. Fan levels can also vary wildly depending on whether it’s idling, working, or working very hard. One option would be to get whatever trolley and replace the fans yourself. But note that they might not be “PC fans” in the sense that they might not be the right size, and more importantly they might be a different wattage. If you take off a noisy 10W fan and stick on a silent 3W Noctua, you are going to have problems. Supposedly you can get “axial fans” from places like RS Components which are quiet because they use different bearings. But regardless of these options, you run the risk of voiding the warranty and you may need to do some soldering or connector crimping. What I opted for in the end was to go completely fanless. Meaning a convection cooled inverter. But note that this will bump you up into a different price bracket, because all of these systems tend to be at least 48V. Also note that these are more DIY than trolley. Though you can make a trolley of sorts with these systems. I wrote some more about the various brands and trade offs in this response to someone asking a similar question on the DIY Solar Forum: https://diysolarforum.com/threads/fanless-noisless-quiet-inverters.43426/page-2#post-637232 JZ

Hi guys, I have a question about AC breaker size. My impression was that the breaker needs to be spec'd for the max sustained output of the inverter. So in my case I have a Goodwe GW3048-EM which has a max ouput (while grid supplied) of 3kW. So if I add 25% I get 3.75kW, divided by 230V is 16.3A. Supposedly you can round down if you are less than half an amp over the nearest standard size. So presumably 16A breakers would be fine. However I am a bit perplexed by something on the data sheet. It says "Max. Apparent Power from Utility Grid - 5300VA". Now I know there is a bunch of stuff related to power factor and the types of loads you run (though you shouldn't be running heavy inductive loads on this inverter at all) resulting in a difference in your real power vs apparent power. But I just don't know where that number comes from. My thought was that it could be a momentary number for a few milliseconds, or perhaps if you are passing 3kW through from the grid and charging the batteries at 2.4kW? My assumption is that is not possible with this inverter, though I could be wrong. At any rate, if anyone could help explain this or point me in the right direction I would appreciate it. I'm pretty sure 16A would work but I'm trying to make sure I understand what I am doing, not just making something that should probably work. Yesterday was a rabbit hole of correct grounding practice which led to a very helpful post by Gnome about using 230V coil SPDT relays. EDIT: Ok so I overlooked something major. The spec sheet says that this thing can pull a max of 23.6A, that's like 5.4kW at 230V! How is that possible with a 3kW inverter? I don't think that is an instantaneous figure either.

Hi @DRB, ”Anything to look out for” is a bit of a broad topic, but I can give you some pointers: 1) Check the C rating of the battery. This is term of merit for describing how much charge/discharge the battery can do. A battery with a 1C rating can fully charge or discharge in an hour, whereas a battery with a rating of 0.5C or C/2 can only do it in 2 hours. This is important because, say you have a 4.8kWh battery. If its C rating is 1C, it can output 4.8kW for an hour. Whereas if its C rating is only 0.5C you are limited to 2.4kW for 2 hours as the max. In this way, you can end up with a 5kW inverter and a 5kWh battery that can only output half of what you need. In that case you would usually solve the problem by buying two such batteries, or one battery with a 1C rating. You don’t generally want to run your batteries that hard, but it’s good to have access to your full potential for things like kettles and microwaves. 2) Battery chemistry. Not all lithium batteries are created equal. I am speaking under correction, but I think the Hubble AM2 you quoted is NMC lithium-ion, as opposed to LFP (LiFePO4/lithium iron phosphate) or LTO (lithium titanate). Broadly speaking, LFP is preferred for home use due to long life, relative cost effectiveness and stability. They never catch on fire or blow up. I think NMC is a bit denser, meaning the battery can be smaller for the same amount of juice, but it’s not as safe. Hubble makes good stuff though, and other batteries from the AM series (I think 5 and 10, possibly rev-2) use LFP cells. Lithium titanate is only required if you need to charge below freezing point, or if you want cells that will last 50 years for some reason (at 2-4x the price). I believe that we will have much better batteries 10 years from now, so I don’t need my cells to last that long. 3) Check the warranty (both seller and manufacturer). In addition to COC you often need a by-the-book setup in order to qualify. This can sometimes include unexpected things, like I believe Pylontech requires at least 2 batteries in parallel (for most of their rackmount systems anyway) to qualify. 4) Be careful where you buy from. There are tons of scam sites around, sadly. If a price seems to good to be true, it very likely is. Being able to show up in person and test a battery before taking it home is always a bonus, and they weigh a ton so it will save on shipping too. With that being said, there are plenty of reputable online dealers including this fine forum. Hope that helps! JC

I can’t say definitively which the best one is, a lot of that will have to do with your requirements. For example you mention noise, how big of an issue is that? For me, noise is a deal breaker, so I ended up spending quite a bit more to get a fanless 2.3kW Goodwe inverter. What you need to look at are the features. Some of the cheaper ones only have PWM charging from solar panels instead of MPPT. The King series allows you to blend power from solar and batteries at the same time instead of just using one or the other (but it has some issues with certain types of loads due to being a simulated “online” UPS). It’s also possible to turn down the charge current if you don’t want to add thicker conductors and heavier breakers. You can always change this later. If you don’t plan on using solar or blending, you could probably get away with the cheapest PWM variants. This is a bit of a tangent, but I think it bears mentioning that there is a difference between Axpert, and “Axpert type” inverters (clones). For the record I think Synapse are Axperts. [EDIT: According to Coulomb these are likely clones] This forum is full of people who have used both types to great effect, but speaking broadly: When Voltronic made the Axpert/Infinisolar range (the ones that get rebranded by companies like Synapse, Kodak, Full Circle Solar, Mecer etc), they created a competitive product by drastically undercutting what was already available. How did they do this? Some vertical integration and production efficiency gains, I’m sure, but also by using cheaper components and cutting a few corners. These inverters, while imperfect, are well respected in the community and seem to do the job pretty well. However, when you get into “Axpert type” or Axpert clone inverters, you are taking on a new level of cheap components and cut corners. I am not trying to ruffle any feathers here. Everyone is constrained by budget to some extent and a lot of people have had success with cloned inverters. I’m just saying one needs to be careful because they aren’t the same thing.

Hi @Trish, I’m not David but I can answer your question. It’s hard to say how long a new battery would last compared to your old one when it was new. Gel batteries are supposed to be set up to only use half of the battery to keep the battery in good health for longer. This is called using 50% “depth of discharge” (DOD). But if the battery was not set up that way, you could get slightly less capacity from a similarly-sized lithium battery (specifically lithium iron phosphate, or “LiFePO4” as they are known) because LiFePO4 batteries are ideally used from 90% to 10% (in other words, you get 80% DOD). Put another way: If the gel battery was set up correctly, you would get 60% extra juice with a new 12V 200Ah lithium battery than you got from the brand new gel battery. If it was set up incorrectly, you would get 20% less juice compared to when the gel battery was brand new. As long as the lithium batteries you buy are capable of “parallel” function (being connected to other batteries in a way that increases capacity but not voltage, ie opposite of “series” connection), you can add more down the road. So you could get a 200Ah now and another 200Ah later if you wanted. Or you could get 100Ah and add more later. I think you can mix sizes but for simplicity sake I would advise against it, and never mix lithium and gel. My advice would be to get a 200Ah 12V LiFePO4 “drop in” battery, or 2x 100Ah ones connected in parallel. That would probably solve the problem, and get you back to around where you were when the gel batteries were new. Plus they will last at least 8 years, probably 10+. “Drop in” batteries can be used with systems that do not normally support lithium, but you still need to check which charge settings to use on your inverter (eg you may need to change from “gel” to an “SLA” setting, check the manual for the battery). And remember you will need new cables/connectors if you go from one battery to two. Good luck! JC

Hi @Wikus, Have you updated the firmware on these devices?