I have a scaffold set up behind the array. I stand on it lift the panel slightly and slide it sideways. I reset it on the lower row and install spacer blocks between the rows until I tighten up the clamps. If I had a bigger crew I’d do a lift of some sort but this works well for a one man show like me.
11 Likes
ahh I didn’t see the scaffold. that makes more sense. 
8 Likes
We’ve got a similar Magnum inverter, but 24 volts. I’ve found limited information about Magnum’s serial communications. Have you done anything along those lines?
2 Likes
This will probably push you in the right direction, they are saying they use a standard RS485 serial protocol.
3 Likes
When I said I had found limited information, well, you’ve found it, too 
The link to the escaped Magnum document seems to be about all there is. I could build something with an Arduino, and play Trap the Data Stream, but I’d like a less strenuous method, if there is one. I’m thinking it might be faster and easier to just let the Arduino monitor and run the system, and just send instructions to the inverter. I like the Magnum hardware, but I like the Victron open source philosophy.
4 Likes
I just skimmed the thread looking for the protocol doc, but this thread is newer and they are saying basically not much has changed.
https://www.irv2.com/forums/f278/continuation-of-battery-charging-and-the-1-5-9-update-602735-2.html
Magnum-Networking-Communications-Protocol-(2009-10-15).pdf (62.0 KB)
2 Likes
How are you going to use it? It looks like it is just a cell, then you have to make a panel out of it, or at least add connectors and waterproofing.
It is a great find. I didn’t realize they were that cheap. a package of 100 is like 115 dollars on aliexpress.
4 Likes
At beginning, it will be a toy. I am just curious to see how things are working. I spotted the sale at Aliexpress for 40 pcs package. So I ordered two.
Definitely, it’s not worth to build own panels at scale. One may find panels with such cells at price around $150-200. So you can’t beat it in area of quality, safety and performance. But you may create your own smaler solutions focused on special purpose.
9 Likes
That is kind of why I asked. It would be worth if you wanted a custom solution. say a 1 cell high panel to sit on top of an existing fence or even replace boards for a board fence. For .13c/watt or whatever it worked out to, even only using one side isn’t a crime.
You probably already know this but not all clear plastics are suitable covering acrylic, polycarbonate, or PET, which are transparent and UV-resistant are the best.
3 Likes
I have installed Magnum’s “mag web” monitoring kit but it is expensive… Usually clients either go with outback (mostly obsolete now) or Schneiders or Solark all of which offer their own built in monitoring. There are independent monitoring platforms as well but I don’t really get into them.
7 Likes
Hi,
We have an Outback FlexMax 80, and two 48v LiFePo banks with Daly BMS. They power a Sigineer 6048.
So if the batteries get low enough that the BMS disconnects the batteries, it shuts off the FlexMax. The FlexMax won’t power itself back on when it gets pv power. So we have to go “jumpstart” the FlexMax by bypassing one of the BMS. It’s dangerous, and I don’t like it.
(An example of one of the bypass methods one of the boys have used)
I had an idea of using robot batteries which are just small 12 amp hour lead acid batteries to make an auxiliary power source for the flex Max that turned on when a CDs board saw daylight and then a voltage cut off disconnected the lead acid batteries when the voltage was high enough. The problem I have though is the inverter stays on and tries to draw from 12 amp hour batteries which won’t be enough to start the fridge. I’m just wondering if there is another way to do this that’s more sensible?
10 Likes
Why are you using both the flexmax and the daly? It looks like the flexmax has a charge controller on it. I am not saying it is wrong, more just wondering why because from a quick glance it looks redundant.
Second, you might look at the low-voltage shutoff and see if you can manipulate on the flexmax so it is higher (or lower) then the low voltage shutoff for the daly. And make sure the daly is shutting off at the right voltage. One of them is shutting off thinking there is an issue. But I am not completely following the wiring.
last, if you still need to jump it, put a normally closed relay or switch inbetween the lead acid and the life batteries. It is flipping dangerous how you are currently doing it.
The advantage of the relay is it uses a low-voltage input, and you can control it with a microcontroller to shut off after a certain period of time. Later add a circuit that monitors the volts or amps coming from the solar to flip the relay on automatically.
1 Like
I think the FlexMax is matching the solar panels to the battery, while the Daly BMS is keeping the battery cells balanced and protecting the battery. I wonder if a diode, and maybe a series resistor from the input of the FlexMax to the output would let it restart when the array voltage comes back, without frying anything. I don’t know enough about the charge controller or the BMS to know for sure.
Second thought: If the BMS disconnects the battery to protect it, the FlexMax probably sees no load, which might make it very unhappy if it does restart. Is there a way to trickle charge the batteries, bypassing the BMS, until the BMS is satisfied? Maybe something like a low current, isolated DC-DC charger? The diode and resistor might do this.
edit: How much voltage does the FlexMax need to see to start? Maybe s Zener diode from input to output would keep it turned off until the array voltage is high enough to charge the battery, and keep that start-up voltage low enough, below the main battery voltage, that wouldn’t conduct when things are working normally. One would hope the charge controller would start with a voltage well below battery voltage.
edit #2: This scheme might cycle on and off, maybe really fast, if the inverter tries to start before the low battery can carry the load. So, one more guess—can you set the inverter low voltage shutdown higher than the BMS shutdown so this can’t happen to begin with?
1 Like
Daly bms is last safety for the battery. If the chargecontroller is doing a correct job, the Daly doesnt do anything besides balancing. If it shuts down there is something wrong, it shouldnt happen.
Dont know the Flexmax.
2 Likes
I don’t think it is restarting because it sees no voltage. Thus he is adding voltage to make it restart with the lead acid batteries.
I just can’t imagine there isn’t an adjustment for the low voltages on one of the two devices. Especially when lead acid folks used that feature a lot because of the additional wear and tear on the batteries is proportional to the voltage drop.
LiFe batteries can go to zero supposedly without any damage. They just have constant output until like 80% then quickly dive to 0% so catching the voltage fluctuation is a bit trickier then lead acid.
2 Likes
Daly is adjustable. So should the chargecontroller of the inverter. At least LFP should be selected. It is close to lead acid but not the same.
3 Likes
Hmm,
Well it’s an ingenious solution I’ll give you that… It scares the crap out of me though. The root cause of the problem is you are using a very basic inverter with a very advanced battery technology. Any code compliant inverter made to operate with lithium batteries would have a programmable low battery cutoff. You would set the shut off on the inverter 0.1 or 0.2 above the battery shut off… It’s troubling that the BMS is acting like an on off switch since it’s a last resort to avoid damage option not a daily go to. The flexmax does not have a low voltage shutdown because it’s job is to charge batteries so you don’t want it cutting out when the voltage goes low. So how do we solve it? If it was me I would use the programmable relay built into the flexmax to power a small relay. It’s usually used to turn on a vent fan for batteries. Your inverter probably has a port for a remote on off switch yes? If it does wire in a relay that closes with a 12 volt signal from the flexmax on board relay. Program the flexmax to close the relay when the voltage is above the shut off voltage of the batteries. If the voltage drops to slightly above the BMS shut down voltage the flexmax cuts power to the relay acting as the inverter remote switch. Inverter shuts off removing load, flexmax stays on to charge batteries. As a side note I’ve jump started a flexmax on a 48 volt system with a 12 volt battery.
4 Likes
Right! The real problem is the inverter!
3 Likes
I am not convinced. I don’t think you need the outback thing at all. I only perused the manuals for the outback and the sigineer, and they seem to replicate functionality. The sigineer does have a low voltage cut-off for the battery.
The Daly I think outputs in RS485 serial and canbus, and the sigineer accepts both those protocols as well in its rj45 jack. (rj45 is commonly used for ethernet cables, but it is also used for serial communications as well, and usually you can use an ethernet cable)
Then the sigineer can talk directly to the Daly BMS. I don’t understand why the outback is there at all.