sunshine_eggo
Happy Breffast!
FWIW, constant voltage at 13.8V will get you to 98%+ charge over several hours. If you have to leave it on constant voltage, that's the best option.
So a higher charge voltage just charges faster during the initial interval?
But overcharges them if left on?
How does SCC and dc-dc play along all together with that as well? Not that I would or could. I’m thinking driving with the generator running for air conditioning and the SCC not turned off. Engine driving the dc2dc. Should I have switch for that too?
I think I would only use the converter/charger when actually needed.
I’m also installing a bluesea master cutoff switch for the LFP if I want to use the converter on shorepower - without the pack.
I’m going to need to remember to turn off the SCC too.
It’s been said these are not set it and forget it systems.
I can see a scenario where if I make the orion turn on with the key switch, and then if my battery is turned off - disconnected from the system - and I'm plugged into shorepower with the converter providing constant voltage to the house circuits, and then I start the engine - what happens to any power the Orion would generate? Or would it just float along with the load since there's no draw?
Just heard back from Graham.I just called the powermax people and left a message. I'm looking for a response on the design as built and what was intended on the voltage adjust parameters and settings. In doing some research online there are some old RV threads that hashed this out years ago - and the converter units really don't seem much different from what they were a decade ago.
Evidently the founders were originally with WFCO and started another company in competition. And one of their primary retailers was BestConverter guy Randy in Alabama. Boy does he have some negative feedback. Anyway, I just ordered a class-T fuse and block from them, and they sell powermax converters under their own brand: Boondocker.
The other thing I want to know is how the fixed-voltage setting works. If there's a voltage drop to the load then I assume it will push max current up to it's rated capacity - the 55 amps or 100, whichever unit you have. But it seems like any other power supply in that once the load voltage rises up closer to the charger voltage the current would taper off as it reaches a matching voltage. Perhaps someone more knowledgable here could shed some light on this.
If this is the case, then setting the fixed voltage at 14.0 to 14.4 and letting it charge a lifepo pack until the current tapers off, then just shut it off.
Their older models only had a 15 minute boost charge at 14.6 and then the unit would drop to 13.6 for an absorption phase, and once the battery reached full charge it would drop to 13.2 as a float phase. This new charger doesn't seem much different, just that they've eliminated the FLA float setting. They also had their PM4 which had the fourth phase for equalization/de-sulfating. Graham claimed this new charger had a 4 hour boost duration if the pack had low voltage/low SOC.
For anyone with more interest on charging lifepo packs here's a pretty good blog from Marine How To - @Dzl has a link in his sig for these guys:
DIY LiFePO4 Batteries On Boats - Marine How To
DIY LiFePo4 On Boats Last edit;3/26/23:The base of this article was written a number of years ago (2010) but this does not mean the information here is outdated. We have been keeping it updated and have added to it when ever we had the time. This article dealsmarinehowto.com
If it's set to 13.8V (3.45 V/cell), it can be floated at that voltage indefinitely. Maybe go with 3.40 V/cell. But balancing should be done higher in the voltage range where dV vs SOC is steep. So each cell's SOC is more closely matched after balancing.Yeah, the standard PM3-55lk is $145 on amazon. It does the fixed-volts output too:
I think the PM4 is even cheaper and it can do fixed-voltage output as well. 55A is like $135. You just wouldn't use it in the automatic mode, nor leave it connected indefinitely - these need to be shut off when the battery gets full.
No kidding!I like having options - you never know when things are going to go sideways.
Jimmy, bro, cancel your order and/or refuse delivery, whatever you can SEND IT BACK and get your money back pls.I just ordered a PM4 60A charger. Only cost $139. When I get it, I'll be messing with the voltage setting pot to see what I can do to have 2 switchable voltages. 13.6 & 14.4 maybe.
I put it on the 2-stage mode and it charges at 53-54A amps for a pretty short time, maybe three or four minutes, then drops to the float level of 13.6 volts and the amps taper off to about 12. At this point it's drawing 3A at the 120 outlet. The cooling fan runs but is very quiet.
The beauty here is you can have fast or slow charging depending on what you want. I'm glad I can shut it off - I don't want to float it for any length of time at 13.6. It's fine for a day but not for weeks or long term, or when it reaches full charge. The lifepo seems really happy at about 13.3-13.4 volts - the meat of the SOC range.
Op,Smoke and mirrors.
It's not even heavy enough to be a boat anchor.
I am a little curious how long it would charge in the high state with a low battery charge level. I started out today at about 75% - all my cells were a little over 3.35. I am pleased with how close their voltage stays over discharge then charge.
From what I saw, the unit tapers current based on battery voltage in both settings, but in 2-stage it did switch to float mode when my pack was at 13.35. I was going to wait for it to reach the 13.6 float voltage to see if it quit charging, but the current had already tapered off so I didn't want to sit and wait for it.
Charging it at 55A brings it up pretty quick.