Adri

Yes, often. Very often when we believe internet like gospel. Loads of hogwash a lot of the time, e.g. charging batteries off PV at 3 a.m, VOV, VOO, ESCOM's problems will go away, "Batteries at cost price"...... and lots more.

I don't understand all the fuss about VOV and VOO. In 20 years I sold over 300 x '6500' gens (for petrol or LPG), so called because they're all practically the same, including Honda, made in China. A decent sparkie will install a change-over switch and socket for the gen and it will work perfectly up to 4kW load (at 50Hz ... the 6500Va rating is for 60Hz) and will sign a CoC on completion of the job. If it's rated 230Vac output there's no need to modify the alternator or use a transformer. Finish. (It's the usual story : "Bnllsh1t baffles brains"....)

Yes, indeed. Like many on the forum I would really like to know progress on the system. And to learn more about your inverter design. Thanks and good wishes!

This is how a gen should be connected. Note that the change-over switch is centre zero, i.e. complete disconnection. The E (earth) connections remain constant and are not switched. Second pic is internal wiring of the gen. (The gen's output is "floating" because it is not connected to anything else, even E. The "voltage detection circuit" actually controls the voltage on the field winding via slip rings to maintain correct output voltage : called the AVR, automatic voltage regulator). It's as simple as that.

You are confused between 1 phase (your Honda EG6500) and 3-phase gen's. Also if you can't use a DMM or don't have one you are playing with fire and possibly death. Don't go there. Check everything via a good qualified electrician. The answers are simple. You don't need a transformer.

I haven't come across this connection method. Usually the output terminals (230V ac) are both 'floating' and the earth terminal is connected to the gen's body. Use a DMM and measure resistance between each terminal, i.e. 2 x output and E. Between output terminals you should read a very low resistance, i.e. the resistance of the stator windings. If the E terminal reads over 1Mohm to output, but short-circuit to the gen body you are safe.

What does VOV and VOO stand for?

I fiddled much in the last week. I now have bulk set 29.2V (the max. my Axpert allows me to go) and float 29.1V and it's charging perfectly, on either PV or mains. And batt's are still room temp. So I'm thinking it wasn't the BMS triggering the previous 27.5V cutting to float. Possibly the label, spec.sheet indicate the 28.4V limit to have the batteries remain in "safe area". But then is the 100Ah capacity based on 28.4V? Any ideas?

No, the "MK" model has those features to set time but mine ("MKS") does not. The manual is 3.5MB (.pdf) so I have split it into two posts. Axpert MKS-MKS PLUS 1-5KVA Manual on 20140306-pages-1-15.pdf

Google for suppliers, e.g. SparkFun.

27.5V - same as Mooshi. Flashes. That's why I assume it's in float.

20191216 I have copied the most important details from the spec.sheet because I can't attach the .pdf for some reason. I cannot get it to charge above 27.5V. I am thinking that as Coulomb says that the BMS says no at 27.5V and shuts off charging, on PV or mains. My Mooshi never shows higher than 27.5V. I can't speak to supplier yet as it's another holiday here (Mon. 16 Dec.). Akkutech spec1..ods

For my 5 cents worth. I have read every post and if I was handling the soldering iron I would replace every power device in that part of the circuit. As has been said earlier other power devices took a heavy strain and could be partially damaged - perhaps just enough to keep working for a week... Not worth the hassle. Change them all.... t

I am as confused as you are, Coulomb. Perhaps it's a language/translation problem? I will be in touch with the supplier next week and will post new information. Thanks.

Details from spec.sheet of AKKUTECH 25.6V 100Ah batteries : Nominal voltage 25.6V Energy 2560Whrs Charge Mode Constant charge at 0.2C to 28.4V Charge current 20A Max. charge current 50A Charge cut-off 28.4V +/- 0.2V Max. continuous current 50A Discharge cut-off 21.6V +/- 0.8V (reduced info from spec.sheet)

Yes, Taco, am very interested in LFP 25V batteries. Do you have? Price?

Thanks for the reply, Coulomb. The LFPs are fitted with BMS. I have now set the bulk to 28.4V and float to 26.9V. I'll see what happens now and give feedback. (My batteries are in different enclosure, no displays.) AT-SPEC-LiFePO4 Battery 25.6V100Ah SPEC.pdf

Someone might be interested in my monitoring of my batteries : to show true batt. volts and charge/discharge current. I use a Mooshimeter I bought on the 'net. It can display 2 functions simultaneously : my case batt. volts and true charge/discharge current. I connected 3 input plugs to (a) B+ terminal of Axpert, (b) B- terminal on Axpert and (c) B- terminal at the batteries, so creating a small volt-drop. It's then displayed in the 100mV range which is exactly proportional to the current [in both directions]. By quick calibration I measure about 5mV/A. It's that simple and I carry my phone/display anywhere in the house. It has logging functions I haven't mastered yet! If someone needs help/more info, let me know.

My AXPERT 1000VA/24V works perfectly. I have replaced the Trojan T-105s with new AKKUTECH LiFePO4 batteries (2 in parallel). I set the bulk setting (program 26) to highest possible value = 29.2V (instead of 32V). It charges well on PV and "utility" (Heishkom) but at about 27.5V it switches to "absorption" (program 27) and charge current drops to almost nothing. This means in theory that I will never be able to reach max. capacity of 2 x 100Ah. Why does that happen? Shouldn't it keep charging until close to or equal 29.2V? What should I set program 27 to? Thanks.

20190221 After battling a bit I managed to invert the 2 fans. Why 'they' decided to arrange the fans in reverse is beyond me, i.e. sucking warm air DOWN and out instead of pushing cold air UP and into the heat (heatsinks) area is beyond me. Why would they do this? It doesn't make sense to me. Apart from anything else its no good for the fans! Does anyone have an explanation?

First test with Mooshimeter on my system : shows charging at about 2A (uncalibrated yet) with 25V on the battery terminals. First problem : range - when my fon is 10m from Mooshi it drops out. Could that be the Mooshi's batteries? Will test today.

Hahaha...! I have 2 VICTRON 12V 350VA inverters. I tied one in for TV/decoder or fridge while the AXPERT was "faulty" - a very good substitute. (We had 150 min. blackouts from Sun.10 Feb ... Thu.14 Feb.) We are family of 2 + dogs so the offer of the AXPERT was a good one because I already had enough PV and batteries to reconfigure for 24V. I received my Mooshi last week and plan using it to monitor the system.

Thanks so much, guys. You were right. I had set it in "power saving mode". Worst of all is that I didn't read the manual properly or I would have found the "fault" on my own. LESSON LEARNED : Read the %$#@!ing manual five times ! Thanks again for the help and good wishes. Ari.

hi Coulomb, Thanks for the service manual. It does help but I need more...! (Haven't we heard that before?) More clarification to perhaps help me. No load connected - only neon indicator and DMM. The inverter starts up with proper output. After 5 sec it shuts off - I can hear relay dropping out. No fault indication on LCD. After about 1 sec it comes back on for a split-second before shutting down again and repeats this forever until switch off and it tries to start again. It seems to me that there's some extra protection built in somewhere that only detects the 'fault' after start-up delay. So where is this? (In the uP or using opamps tied to the uP?) And what is the 'fault' condition it senses? Any ideas or suggestions or info appreciated. (I am happy the share all I try/test/results.) Thanks so much.

I was unclear about warranty : the unit was originally bought by another business but remained new and unused until I bought it October 2018. I would like to make contact with folk who do such repairs. I am electronics technician (for 40 years) with some experience in PV but still could not find the fault in the unit. (No load connected.) And thanks for the suggestions so far!