I'm sticking with A flooded battery for cycling, as the AGM's seem to require high currents which my Solar cannot meet, and solar is my primary recharging source, albeit the lowest and slowest I have.
I reduced overall capacity bown from two 27's, so my 200 watts of solar could at least approach the 10% rate at noon after march 21 before sept21, so I'll not be increasing capacity either with the T-1275.
Investment wise, this 31 already has outperformed 2 sets of Crowns, but they were compromised by lack of watering due to inconvenient location, and Crown recommends higher charge rates of 12 to 18% last I looked, so my solar was even less well matched on those.
It had been a while since I did a Hydrodipping, and the one low cell and wide disparity was certainly a surprise. I had done some brief 16v MW sessions just watching the amps and would just stop the EQ a bit prematurely.
It would be nice to not have to have the battery at 15.3v all afternoon long while SG slowly creeps toward the maximum. I figure 15.3v is abusive to my lighting and fans.
While the SG readings indicate the end of life ticking, I am not really Noticing this voltage wise under load. Sure it is lower than new, and seems to drop to the 12.2v fairly quickly before rallying and maintaining 12.2 while I hammer it with loads similar to the loads for the 20 hour rate.
Anyway, it has been neat beating up on this battery and concentrating more on getting SG near max as often as possible. It has proven that green flashing lights are liars, each battery is a bit different, and achieving full charge is not just to be trusted to Automatic underchargers or universal converter algorithms. It shows how important Adjustable voltage setpoints are in getting the most from a heavily cycled battery.
And it ain't dead yet.
I'll be keeping an eye on that weak sister cell. It is the easiest to dip, being closest to the (-) terminal
It Still holds the Meanwell at 41 amps for a while when I start it first thing in the morning. 41 amps certainly is not the magical instant absorption voltage current. Constant current still happens nice and flat before the tapering begins. Instant absorption voltage current is in the 70 amp range still.
My 5 day 13.6v experiment was for curiosity. Amps had tapered very low the last 3 says in the 0.3a range. It was for grins, and because the MW allow it, that I bumped it to 14.7v on day 5, which revealed the battery was not fully charged after 5 days at 13.6v. So low and slow, on this battery anyway, is not going to do the job. That was my point.
This battery is getting the Cheapowatt treatment. Pushed until failure for the sake of science. If/when it fails, I still have my AGM battery which can perform both engine start and house duty. But I can also just plug in and not cycle any battery at all and keep them at 13.4 forever, and learn nothing.
I will likely see where I can obtain a trojan 31 for when the time comes, and have a new battery tray fabbed up to replace the one holding the screwy 31. A half inch lower tray would be a good thing too.
BTW, my battery monitor is set to self adjust the charge efficiency factor, and it claims 98%.
Like I believe that. I do have an amp hour counter on the meanwell output, but I usually have loads running when recharging.
I get the impression that you hope for it to roll over and short out a cell.
Did those paisley ties at US battery really hurt your feelings so Badly?
I'm gonna cycle it till it shorts a cell or can't meet my overnight needs.
Tick tick tick.
Is that ticking my battery, or the countdown to a frothy paisley tie rant?
Odyssey's spec sheet says they require 40 amps per 100AH of battery when deeply cycled. I spoke with An Odyssey tech for a whole about a group 31 on 200 watts of solar, and he recommended against it as it is too little of a bulk current for a deeply cycled battery.
I treat my Northstar AGM as if it were an odyssey. When it gets 41 amps from the meanwell after a 50%, it has much more gusto when cranking my engine compared to a solar recharge from 75 to 100% cycle.
I'll not cycle my Northstar unless I have alternator or Meanwell to feed it a high rate the next day.
I really hope to hear back from Powermax soon. It has been back there for several days. Errin said if they could not get 100 amps from it they'd reimburse shipping and send out a tested 100 amp adjustable model.
I want to do another 10 amp for 10 hour load test on those NS 31's and then give them 100 amps constant current to 14.7v and hold 14.7 until they require less than 1 amp again.
My NS holds 13.06V weeks after charging source is removed. I want those new 31's to do the same.
The project vehicle for the 31's has changed, and project is in limbo until new project vehicle arrives.
@ ~ 370 cycles on screwy 31.
About 20 more cycles Since last report a month ago.
One morning, at 55 AH from full I turned the MeanWell to 13.6v, Lowered solar max voltage to 13.6 and let it go, for 5 days. Not cycled 1 amp hour.
On day six, I turned MeanWell upto 14.7v, and took 9 amps to get there, and 2 hours later it finally tapered down to 1.7amps. I didn't check SG.
Then the cycling started up again. 35 to 55 AH each night.
Last night at 1AM, 46AH from full. 11.9v under a 4.8 amp load. Rebounded to nearly 12.1v when load was reduced to 0.7a.
Not too bad considering it has been cooler.
Today Solar and MeanWell held 14.9v for 4 hours.
1.225, 1.265, 1.275
Switch loads to AGM, bump screwy 31 to 16V measured at battery terminals via the MeanWell. 6.19 Amps required to reach and attain 16v.
Weak cell did not respond at all for 25 minutes, then it jumped to 1.250 at minute 30
2.5 hours later
1.275, 1.280, 1.295
Amps had tapered to 5.59, and had started rising again by hour 3 hours to 5.83 when I terminated EQ cycle.
Electrolyte level is a little less than half way between tops of plates and bottom of hanging arms. Electrolyte kind of cloudy on weak sister cell, but not grey and no visible particles despite vigorous bulb squeezes down one side of cell and bulb filling from the other side.
Now where's my Whip? Time to start racking up the cycles.
The "100 amp" PowerMax Adjustable voltage model stopped at 75 amps on a pair of NorthStar AGM's group 31's(100 AH each) in parallel via 00 gauge cable. They had a 10 amp load on them for 10 hours previous to starting charge cycle. 1 hour after load removal voltage had rebounded to 12.19v. NS says 50% is 12.11v.
Bumped Powermax to 14.7v unloaded, and disconnected PM from 116Vac.
Attached "100 amp" PM to parallel AGM's via 0 gauge cable. 3 feet one way. Plug in Powermax. Flip switch. 76.2 amps. 50 minutes later as battery voltage nears 14.7v, then amps begin tapering. Nearly 12 hours later, amps required to hold 14.7v finally tapered to 0.95a. Terminate charge.
Somebody.....tried to tell me that these 2 agms couldn't handle more than 75 amps when depleted to 50%. Effing BS! If the batteries were the limiting factor, amps would have tapered immediately, not 50 minutes later.
24 hours later batteries read 13.09v
10 days later batteries read 13.00.
Powermax returned to Bradenton Florida with Note attached after talking with proprietor.
No word back yet. This better be made right.
The unit was originally shipped from Bradenton. On the side of the shipping box, there was a check mark next to the PM3-75.
On my old laptop, powering the original power brick with a msw inverter did allow it to charge, but the battery would run down much faster compared to grid powering it, and the laptop would slow down to a crawl after the battery indicated full charge and the MSW was still powering the original power brick.
MSW also ruined a sears craftsman cordless drill battery charger.
MSW might be fine for many things, but it hurts when it is not.
Please note that the MW switching power supplies vary in their abilities, and internal protections.
I did sacrifice a cheapowatt in the name of science. cheapowatt thread
In short, I wanted maximum amps until the battery reached Absorption voltages. The cheapowatt, rated at 350 watts would output much more than this, and overheat, as it has no internal protections against overload. To get maximum amps I had to keep twiddling the voltage trim pot to just below the area where it buzzed. When I got sick of this I just set it to 14.9v, hooked it to my depleted battery, and let it buzz away. 17 minutes later smoke and flames. A fun 23$ experiment, and it lead to acquisition of my Meanwell rsp-500-15 whose performance I am extremely satisfied with.
Do note that some of the Meanwells shut down on current overload, while others do constant current limiting on overload. You want constant current limiting for battery charging. The Meanwells have good data sheets on each model they sell, so look for this feature if you choose this route.
I've yet to bother with a timer installed on my MW. If I fear forgetting about it, I just set the voltage to 13.6v rather than 14.7 or 14.9. If I need full output and quickest possible battery charging times then 14.9v it is.
I've noticed after days of 13.6v on my flooded battery, that cranking it upto 14.7+ is still needed for an hour or 2 to max out the SG, on my screwy 31. When the SG is not maxed out, I can easily notice the lower voltages during discharge. So, at least with my screwy 31, I am not in the 13.6v will eventually fully charge the battery camp. It needs rather extreme voltages applied to fully charge and perform properly.
It really tanks in performance quickly if not brought to 1.275+ SG regularly
If T105s are in your future, Trojan recommends a 10 to 13% rate, so 23.2 to 30.12 amps should be the minimum amperage charger you get, assuming the converter will be powering no loads whilst charging in the Constant current/bulk mode.
As Mex says you can certainly go bigger. I regularly hit my group 31 130 AH flooded battery with 41 amps. It can take a lot more than that when depleted.
If you got an hour to run a generator to charge a depleted battery, do you want it to replace 30 amp hours or 60?
Hint, it's 60.
Also, Trojan recommends 14.8v Absorption voltage. PD only does 14.4v.
Iota will do 14.8v
Powermax will do 14.4v, but will do 14.6v if bought from bestconverter.com.
Powermax also sells the adjustable voltage stageless converters. Nothing Automatic. You can hold Absv for a week if you desire( or forget), or boost voltage in to the mid 15's for an EQ cycle.
Or set it to 13.2v when your batteries are charged or you have all the time in the world to recharge.
These adjustables are nice as one can hold the battery manufacturer recommended absorption voltage for as long as required to max out Specific gravity, and hold it higher to get the most out of the time you have to run the generator.
All the other Automatic 3/4 20 stage options are premature floaters, for fear of overcharging and greedy lawyers.
Well, I opened up the cluster, removed the limiter, and there, in the same place as the photo in the OP, is a little adjustment knob.
I could have easily moved this during cleaning. I don't have an analog voltmeter so I cannot adjust it properly, and I do not know what it was actually set at before. Also with its age, perhaps it is foolish to put this back into use after adjusting it.
It strikes me that I have the opportunity to dial in my Fuel gauge so half a tank actually indicates half a tank, instead of indicating 5/8ths a tank. This unit appears to fit this bill nicely. I could mount it remotely to easily adjust the set screw.
DROK 3a buck converter
While the temp gauges and OP gauges will have a 'new' normal range, I have a mechanical OP gauge plumbed in, and merely tolerate the Stock gauge. The Oil light is still operational as well.
I decided to practice soldering with my newish 100/140 watt weller gun. The primitive circuit board has a bunch of pins with a mechanical connection. They all now have a nice base of solder meeting the traces.
Same with the voltage limiter attachment points.
Here's to rock steady gauges in my future.
There is a capacitor on the CB traces between (+) and (-)
.47M250 V U
The V is actually a triangle.
Thanks for all the input. Others have already blazed this trail before:
I'll just have to follow.
35$, my Donkey.
That top photo in the OP, shows a little adjustment knob. I did not notice this on mine, but I imagine if it is there, I bumped/ turned it with a Q tip.
Frying the gauges is not something I care to do, so the solid state option will be the path pursued
Hmmm. 5 volts DC
Same as a USB plug output.
All sorts of options to consider:
Could be an extremely simple solution....
I found this link online which shows some internals, and modern(2002) solutions
I'll not spend 35$+ for this ancient technology when better modern options exist for a fraction of the price.
I'm guessing some DeOxit d5 got inside the unit and affected the resistance of the unit.
I'm only going to open the old one once I have a working solution in place. I fear letting the smoke out of the gauges, and am just going to unplug the limiter now until the new product arrives.
Well the factory service manual says 5 volts. The Standard motor parts replacement says 6 volts. I can't measure an average voltage with my tools but I suspect it is now significantly higher than before the cleaning.
Opening this original up will not be so easy.
I'm just having a hard time considering spending 35$ when a steady 5 volts, or 6 volts, or 5.547v can be applied with a 5$ piece of modern electronics.
I am 5 3/8" nuts from accessing it right now.
Thanks for quick response. So I imagine the LM 2596 supplying a steady 5 volts would also operate the gauges properly?
I have one of those on a computer fan whose hub gets too hot at Absorption voltages and it holds a rock steady voltage no matter the input voltage, and has been plugged in for 6 months now, continuously.
Any theories as to why my cleaning of this stock unit caused the range to change and raise my gauges?
This is a Voltage limiter, for my Fuel, coolant temp, and oil pressure gauges in my '89 Dodge van.
It plugs into my gauge cluster and is not extremely simple to access.
My Factory service manual says this limiter sends out" AN EFFECTIVE 5 VOLTS" to these gauges
In another part of the manual, it says when testing this limiter, if the voltages fluctuate, then it is operating properly.
My voltmeter is jumping all around when attached to the output and ground tabs. The input is steady battery voltage.
Recently, because of high amounts of stubborn oxidation on the glass fuse holders, I decided to open up the dash and get some Caig Deoxit on the connectors and make them gleam like oiled chrome instead of white 320 grit sandpaper. The Fuel and temp gauges, in the past have swung in unison fairly wildly, So I really wanted to get to this voltage limiter and clean the contacts.
Anyway I did so, and now all the gauges read high. Much higher than normal, higher than they seldomly swung in unison before.
They say this can be a faulty voltage limiter, or a bad ground. It is not a bad ground. And I fear my aggressively cleaning the tangs of this limiter with a wire brush on a dremel, screwed up the internals.
It is 35$ for a new one which seems a bit ridiculous. The Pic above shows a few tangs that one could pry up and access the internals. The one in my dash cluster has a full perimeter seal making access to internals much more difficult.
So how do these things work?
Why is it not a steady 5 volt output but instead jumps all over the place?
How could my cleaning of it with a dremel and soft wire wheel, and Caig DeOxit d5 cause it to read so differently and raise all my gauges?
(The temp gauge now reads 25% higher than ever before, well outside the normal zone. The engine is running at its normal temps.)
If I were to give the dash gauges a steady 5 volts from a device like this, will they operate in their correct range?
The danger to the alternator is the heat it generates when it is making lots of juice to power lots of loads. When idling there is much less underhood airflow as opposed to when moving and less cooling of the alternator
The fact that you are running two heating pads at least means the underhood ambient temps should be lesser as well, and overheating it less of a concern.
Your Electrical mishmash is a bit of a nightmare.
You need to get those house batteries to charge from the alternator so you need not open the hood or waste power by inverting DC to AC to power an AC charger to feed DC batteries. Wiring up a continuous duty Solenoid to the alternator to feed house batteries with engine running is quite simple. Fat cables insure adequate charging.
YOu should also get a DC to DC laptop power supply/car adapter. While the ciggy plugs on these prove troublesome, there is significant energy savings to be had here. In amazon electronics plug in laptop make and model and add 'car adapter'
Those inexpensive dorm fridges are power hogs. If you plan on doing more existing without hookups, then a 12v compressor powered chest style fridge/freezer will be a much better option.
The HF inverters are cheap for a reason. The cables being thick can mean the insulation is thick and the copper is thin. I commonly see 12 awg jumper cables in the drug stores, whose insulation is so thick it appears they are 4awg cable.
If you are going to be spending more time away from 120vAC hookups, you will need to upgrade your equipment. If you continue to use the engine starting battery, it will soon fail, as starting batteries cant handle being cycled deeply many times.
Seeing as how fully charging to a true 100% any battery takes hours and hours no matter how big and shiny the alternator or battery charger, and batteries walk down in capacity when not regularly truly fully recharged, your stop gap measures to meet your electrical demands, will just get worse and worse as your batteries get abused and age prematurely.
Regarding the battery charging circuits, spend more on Copper now, or spend much more on Lead later. As happens often in the RV world, trying to save money initially costs more in the long run. Throw in a little incomplete understanding of things electrical, and one soon finds their purchases are now just expensive paperweights, not fit for the job they were bought for.
Any Smart charger's charge algorithm will be a compromise designed to safely undercharge any battery.
The marketer's are depending on that placating green light full charge indicator to sooth the masses, and making up new 'stages' of charging to impress those waffling on a purchase decision.
Reviews on Amazon by the seriously uninformed mean less than nothing.
If the charger has a maintenance/ float mode, it likely will eventually fully charge a battery if plugged in for long enough. But there better not be any load on the battery or you will find the flashing error code.
I got used to seeing my old Schumacher sc2500a flash the green light, drop to 13.2v, and yet the battery still required 5 amps to hold 13.2v. Fully charged, my buttocks. Other times it would blast right past the mid to high 14's up into the 16's at 15 amps while the battery fizzed like a just opened soft drink.
Screw Automatic smart chargers and the marketers thereof.
Even if the batteries were 70% charged, I'd expect a 130 amp charger, to output 130 amps briefly on those 2 large batteries.
How thick and long is your cabling between charging source and battery bank? This has a huge effect on charging amps. If the cabling is thin, then the voltage potential is less and the amp flow limited.
Also check for warm or hot cable terminations at charging source or battery terminals.
One can certainly start a 39 amp megawatt at a lower voltage to not exceed the Honda 1000 output.
I would not set it below the battery voltage however when starting, though I assume the unit has low voltage protection, unlike my cheapowatt which would emit strange noises like a ticking and whining bomb, when battery voltage was higher than the chosen voltage.
My Meanwell can do 41 amps, and I when I do set it to 13.2v, and hook up a depleted battery at 12.2v, 41 amps do flow, for a few seconds before tapering.
When I crank it upto 14.7v on a rested ~12.2v battery, 41 amps will flow for close to an Hour before tapering begins.
It is quite interesting watching how many amps flow at different applied voltages. The cabling between battery and PSU should be nice and thick. I use a few feet of 8awg through 45 amp anderson powerpoles and get 0.25v drop between voltage at terminals and battery voltage, at 41 amps.
Since the Megawatt's iny voltage pot only has a 270 degree sweep from minimum to maximum voltage, one can take note of the desired end position when in the end of CV stage and the battery is taking few amps and voltage drop is not much of an issue.
Solar is great for mitigating draws, and top charging, but blasting the batteries with higher amps, which mine seem to enjoy, requires other charging sources.
Low and slow does not always cut it, despite the affinity for the word 'trickle' by the general public regarding battery charging.
I thought it was fairly obvious that the casing of these power supplies were used as heatsinks for the transistors.
Since my Meanwell rsp50015 is on my cabinet door, I wanted some stress relief on the input and output power cords so as to not repeatedly stress the circuit board wiring receptacles. I had some aluminum window screen sections left over, and used these to attach the input and output cables. They are just over 1/4" thick and add some small percentage to the heatsinking, and of course allow airflow underneath the unit.
Thanks to Westend, I have lots of large finned heatsinks, I just have not shaped and adhered them to the casing adjacent to the transistors to assist heat removal.
It has to be over 70F and maxed out at 41 amps before my Meanwell's loud and powerful 40MM fan powers up. Otherwise the two quiet Noctua fans work admirably, and the unit does not really get warm providing 20 amps anyway.
I love my MW power supply. So do my batteries.
No Automatic underchargers for me.
Automatic smart chargers need to be tricked into fully charging a battery.
When the lying green light illuminates, disconnect and unplug charger, turn on a load on battery to drop voltage below 12.6v, and restart charger. I had to do this a dozen times on an abused marine battery that was used for powering a trolling motor before I could get Specific gravity up above 1.265. Originally the green light came on at 1.215.
The owner of battery and smart charger simply believed the green light. He had total faith in the green light. His world was shattered when a Hydrometer proved the green light was a simple Liar.
I'm sure he went back to believing the soothing green light as soon as I left. It was simply too far outside the fully automatic mindset that permeates society today.