Jimmy, I have the Powermax Lithium version converter that has the 3-position selector switch for: 3-stage, Li-Ion 2-stage & Fixed. I'm looking at relocating that switch (and associated led indicators) from the converter to an external location similar to your resistor/switch setup. That way I can easily switch between 2-stage and fixed when I need the fast charge current (Bulk) when Boondocking on generator. Interested in your thoughts on this configuration. Thanks.
New PowerMax Lithium Series Converter/Chargers
- Thread starter Browneye
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This 'go-boating guy' will should you to death. 
As an aside, the meanwell chargers set for two-stage charging SHUT DOWN when the charge current reaches 5%. They do not 're-boost', they have to be reset or power-cycled to start over.
I can't comment on the technicals of the victron ip chargers.
As an aside, the meanwell chargers set for two-stage charging SHUT DOWN when the charge current reaches 5%. They do not 're-boost', they have to be reset or power-cycled to start over.
I can't comment on the technicals of the victron ip chargers.
krby
Solar Enthusiast
Sorry for the necropost, I'm trying to figure out the max wire size that will fit in DC terminals of a Powermax PM3 or PM4. From a previous project, I've got 2/0 AWG. It's oversized for a 55A model, but I have it and ring terminals for it so I could to use it for the whole project. Looking at pictures, it looks like the terminals are too small, if I'm going to buy wire, would like to buy the right size.
According to the diagram on their website for the PM4 the DC terminals are spec'd for 2 or 4 gauge cable. 2/0 is going to be too big.
PM4 Series - PowerMax Converters in 12, 24 & 48 Volts
AC to DC Power Converters can be used for RV Converters, Car Audio Power Supplies and any Battery Charging for 12, 24 & 48V systems
powermaxconverters.com
krby
Solar Enthusiast
According to the diagram on their website for the PM4 the DC terminals are spec'd for 2 or 4 gauge cable. 2/0 is going to be too big.
PM4 Series - PowerMax Converters in 12, 24 & 48 Volts
AC to DC Power Converters can be used for RV Converters, Car Audio Power Supplies and any Battery Charging for 12, 24 & 48V systems
Ahh, thank you. 4AWG cable with appropriate ring terminals (batteries and inverter both have M8 studs). Looking at that diagram, I really want to put a ferrule or something similar on the end of the cables. Any suggestions?
S Davis
Solar Addict
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Since you want to use 4 gauge, a ferrule should fit just fine in that terminal. The challenge that I had with ferrules larger than 6 gauge is that crimpers are less common. They exist, but they're harder to come by and can be somewhat expensive for a good one. I wanted to use a ferrule on some 1 gauge cable. I bought the ferrules and then bailed on the idea because of the selection of crimpers. At the time, I had a tough time finding a 1 gauge die to fit my ratcheting crimper.
Because I have ferrules and a ferrule crimper for 6 gauge, I probably would use 6 gauge wire. But 6 gauge is good for only about 14' (7' one way, each wire) at 55 amps for 12 volts.
Since the terminal will fit up to 2 gauge, when you use a 4 gauge ferrule you may be making less surface contact than if you used no ferrule at all. It's hard to tell from the pictures on the PowerMax website if the bottom of the terminal is flat or not. Most crimpers for the size you're looking at will produce square crimps (as opposed to round/hexagon crimps that you can get with smaller size ferrules). A 4 gauge square crimp probably will fit in that terminal. When you get the converter on-site you may decide that a ferrule isn't a good fit.
krby
Solar Enthusiast
Thanks for the replies! The PM4-55A showed up yesterday, the cables and ferrules show up tomorrow. I have a cheap (random supplier from Amazon) hydraulic crimper that I used for 2/0 gauge ring terminals for a previous project I've posted about on this forum. It has dies down to 6AWG. well, it has the mm^2 sort of close equivalents. It's not a high quality tool, but it has worked for me for at least 10-15 crimp so far.
Looking at the Powermax unit now, the terminal is a round metal "tube" with a set screw in the top. This looks like it is attached to a post on a PCB inside the unit. I'll take a look once the ferrules show up and see how it goes together, my hydraulic crimper makes a sort of 6 sided shape. I don't love bare wire in terminals, but it may be the best option for maximizing contact area. I may even open up the case and have a look at the thing the external terminal block attaches to, Maybe I can get ring terminals to work!
Another random note for anyone else buying these. I ordered a PM4-55A from Amazon, but the box is clearly a PM3 box with some PM4 stickers on it. I emailed someone at powermaxconverters.com and got this reply:
Looking at the Powermax unit now, the terminal is a round metal "tube" with a set screw in the top. This looks like it is attached to a post on a PCB inside the unit. I'll take a look once the ferrules show up and see how it goes together, my hydraulic crimper makes a sort of 6 sided shape. I don't love bare wire in terminals, but it may be the best option for maximizing contact area. I may even open up the case and have a look at the thing the external terminal block attaches to, Maybe I can get ring terminals to work!
Another random note for anyone else buying these. I ordered a PM4-55A from Amazon, but the box is clearly a PM3 box with some PM4 stickers on it. I emailed someone at powermaxconverters.com and got this reply:
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Just FYI, there isn't a lot of confidence in those people as a reliable source of products or information. They appear to be a sales promotor of imported China goods. The head guy doesn't even know what the spec was on his new units, claiming the POT would adjust boost and float voltage in the 2 and 3 stage modes - it does not. He blamed 'engineering'. Sure.
My unit simply quit sensing or measuring battery/bus voltage and would not charge - the green indicator light would just flash. I sold it on ebay - evidently it works for the buyer as I never heard from them again. I was prepared to buy it back if it didn't work for them.
The Meanwell charger I got works just SO much better, adjustable charge voltages, and it's very quiet. The PM55 was a noisy beast - you could hear the cooling fan whining away in its compartment, and it pretty much ran for all charging current. The Meanwell NPB750 unit is 45A, so pretty close. I got a 450 which is 25A, good enough. The downside of these chargers is they don't re-boost, they have to be power-cycled. Which is fine for a mobile application where you have intermittent connection to 120VAC anyway. For a fixed application that could be an issue. And their smaller units have an voltage adjust pot instead of dipswitches or a BT app.
Worse, the Powermax charge profile isn't a good match for lifepo4. In automatic charge mode it would over-volt cells. In fixed mode it would just never shut off. I put it on a switched outlet so I could turn it on or off as needed, but it became a PITA so it got junked.
My unit simply quit sensing or measuring battery/bus voltage and would not charge - the green indicator light would just flash. I sold it on ebay - evidently it works for the buyer as I never heard from them again. I was prepared to buy it back if it didn't work for them.
The Meanwell charger I got works just SO much better, adjustable charge voltages, and it's very quiet. The PM55 was a noisy beast - you could hear the cooling fan whining away in its compartment, and it pretty much ran for all charging current. The Meanwell NPB750 unit is 45A, so pretty close. I got a 450 which is 25A, good enough. The downside of these chargers is they don't re-boost, they have to be power-cycled. Which is fine for a mobile application where you have intermittent connection to 120VAC anyway. For a fixed application that could be an issue. And their smaller units have an voltage adjust pot instead of dipswitches or a BT app.
Worse, the Powermax charge profile isn't a good match for lifepo4. In automatic charge mode it would over-volt cells. In fixed mode it would just never shut off. I put it on a switched outlet so I could turn it on or off as needed, but it became a PITA so it got junked.
krby
Solar Enthusiast
Thanks for the feedback. I'll be using this as a UPS, so it will be stationary and hooked up to AC nearly all of the time. Because weight isn't an issue and I'll barely cycle the batteries over the next 5+ years I'm using AGM batteries to save cost. I trust and like MeanWell PSUs, and would use them, but I really need something that will work unattended and will handle a 100% duty cycle (vs just being a charger that expects to get shut off.
I did get some ok information from their engineering contact (listed on the website), Connor.
Hopefully this works as advertised, if not I'll end up buying an Progressive Dynamics, IOTA, or maybe an AIMS unit.
I did get some ok information from their engineering contact (listed on the website), Connor.
Hopefully this works as advertised, if not I'll end up buying an Progressive Dynamics, IOTA, or maybe an AIMS unit.
That makes sense.
I don't think the 3-stage charge voltage is adjustable - you'll be able to check that out when you get it. Be sure to do that before you spend a lot of time fully installing it.
I had a IOTA with IQ4 for FLA prior to upgrading to LFP - it was nothing short of fantastic. Ran it for about 15 years or so. It would keep my GC2's fully topped up, equalize them, and they only needed water every couple of months. I replaced the set once in those 15 years. When the second set started to lose a cell I decided to migrate the whole system to lifepo4. IOTA is not a good option for lifepo4 either - charge voltage is too high, and equalization cannot be turned off. Perhaps it its basic form, but the one I had the IQ4 'smart dongle' was built in.
I don't think the 3-stage charge voltage is adjustable - you'll be able to check that out when you get it. Be sure to do that before you spend a lot of time fully installing it.
I had a IOTA with IQ4 for FLA prior to upgrading to LFP - it was nothing short of fantastic. Ran it for about 15 years or so. It would keep my GC2's fully topped up, equalize them, and they only needed water every couple of months. I replaced the set once in those 15 years. When the second set started to lose a cell I decided to migrate the whole system to lifepo4. IOTA is not a good option for lifepo4 either - charge voltage is too high, and equalization cannot be turned off. Perhaps it its basic form, but the one I had the IQ4 'smart dongle' was built in.
This is similar to my IOTA experience. However, in my case, the charge for LiFePO4 was safe, but not hot enough. If I was charging from generator, I wanted a full 55 amp charge. Instead, the charge was weaker against a battery bank that was at a state of charge that should have received a full 55 amps.
My Multiplus kicks ass. The IOTA with LiFePO4 IQ4 is sitting in the garage somewhere.
krby
Solar Enthusiast
Ya, I used a Multiplus 3000VA unit in a different project a few years ago and I love it. Decided to cheap out on this DIY UPS because I already had an inverter and hoped I could just add a converter charger. We'll see if I regret it. It's not critical if it fails the first time I need it and discover I should have just bought quality gear in the first place.
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