Temp-compensating charger: DP Paramode?

[Crank]

I started a long and informative thread on the subject of house battery selection for my 20' 94 Roadtrek Pop. last year. (I like to boondock & hate commercial camp sites, except for one night to dump & shop). I have decided on two Lifeline AGM 100Ah batteries, that I can just squeeze in with some hacking. (I like 12v, because I can use one as a chassis battery in an emergency, and a dud 6v leaves me with a 6v I have no use for.) Alternatives which will fit my space are one or two Trojan 12v 140 Ah T1275-AGMs or 2 Lifeline 6v GPL-4CT (no hacking needed).

(In case anyone wonders, I don't know my daily power consumption: I have switched to LED, and the only other uses I foresee are propane refrigerator control, fantastic Fan and some computer time plus the usual parasitic losses (doubt I'll use the furnace & fan).

The discussion turned to how to charge them, as my old, single step 32amp Magnatek 6300 is unsuitable. I have an Onan, but don't want to use it unless necessary (hence 2 batteries). I won't do solar.

The battery charging parameters need to be correct and temperature-compensated (essential to AGM): I could not find that combination after a lot of looking last year.

I thought I had hit gold when someone suggested a configurable inverter/charger, but they are complex, expensive and not really what I need. Another issue is that I think I need a higher charge rate than 32 amps which presumably means I have to replace the whole unit, which is not that much more expensive than a slide-in upgrade.

While mulling over the problem I just found that Progressive Dynamics (PD) now makes a multistage converter/charger with a Charge Wiz and integrated temperature compensation. I believe it also has an optional button to put it into Boost Mode. It has exactly the correct charging parameters for the Lifeline AGMs: the 55amp model, called the 4455TC ParaMode seems just right for Lifelines. Around $175. (The charge parameters are not quite as good for the Trojan, lacking a high enough finish charge: completely charged batteries are important!)

I am interested to know if anyone has had experience with this or an equivalent unit. I ran across a couple of highly charged () discussions on this topic, but I concluded the fiercest critics had never owned one (seem familiar? PD has come a long way from the Magnateks they inherited.) It seems that while not perfect perhaps, it is the closest thing to perfect I am going to find.

Also, I have been unable to find any installation instructions for this unit, and don't know if it comes with any: maybe it will be obvious. I'll be on the phone on Monday with Parallax and Bestconverter seeking answers, but I hope to find unbiased information here.

Thank you for your thoughts.

[booster]

Yep, very little information on that unit anywhere I could find either.

The basics they talk about that it does a full 4 hour boost each time plugged in. This is typical of most PD chargers, but the one Marko has doesn't do that as far as I know. His seemed to be checking voltage at the start to see if it should float or bulk, like many other brands do. I would definitely check on that part.

It says with "alternate wiring" you can activate the boost mode if you want, which is typical of many of the PD chargers. Some, again Marko's I think, don't seem to stay in the mode changes, just show it for a short time, which doesn't do you a lot of good for monitoring and controlling your charging manually. Another thing you should find out, and also if you can go to boost or float from each other, and have it stay there until a longer time out like 4 hours. You will need to go both ways. I don't remember off hand if you have a battery monitor or not.

The temperature compensation seems to be pretty typical, except that their maximum voltage is at 14.4v, so you will get very little compensation to the higher voltage/colder temperature side. Probably just .1 volt. For comparison, our temp compensation is running + .3v in our 60 degree F garage, so you would be quite low on voltage for cold temperature charging.

Hopefully, you will be able to get some installer or OEM manuals for the unit.

Has anyone said if this is just a different labelled PD charger? If so, the PD manual might work.

[Crank]

Thanks for the extra questions you add, Booster.

I don't know what Marco has: maybe he will chip in.

I think one can always go back to boost if necessary, simply by disconnecting and reconnecting. You think 4 hr at Boost will be insufficient?

I don't have a monitor yet - I'm waiting until I know what else I will buy in order to optimize the choice: most recommended the Trimetric.

You are of course correct that the temp. comp. is lacking much below 70F. But I don't know of any alternative - this is the first unit of its type I have found that has ANY compensation: do you have a suggestion?

Regards,

[booster]

Originally Posted by Crank

Thanks for the extra questions you add, Booster.

I don't know what Marco has: maybe he will chip in.

I think one can always go back to boost if necessary, simply by disconnecting and reconnecting. You think 4 hr at Boost will be insufficient?

I don't have a monitor yet - I'm waiting until I know what else I will buy in order to optimize the choice: most recommended the Trimetric.

You are of course correct that the temp. comp. is lacking much below 70F. But I don't know of any alternative - this is the first unit of its type I have found that has ANY compensation: do you have a suggestion?

Regards,

I hope Marko jumps in also, he had done a bunch of working with his to see what would put it in and out of boost and float.

The 4 hours can, and probably will, be too much sometimes and too little other times. Even though the bulk charge will pretty much always take you up to about 80% before the absorption states, the absorption time to full will vary with the depth of discharge you had. When I tested ours, going all the way to totally full at about .2% of capacity in amps, it could vary by nearly 4 hours. That is why it is important to be able to force the charger both ways, to absorption and float.

The temp comp thing is really odd, I think, as a lot of chargers have it in them, including some fairly low cost ones, but none allow forcing of charge stage like PD does on at least some of their chargers. Put on top of this that PD has traditionally not had temp comp and you get a catch 22 when it comes to two of the most important parts of accurate charging and couldn't get them both at the same time in a reasonably priced charger.

You may be stuck on the cold weather compensation, but at least it is to the side of lesser hurt to the batteries. High voltage at high temps is said to be the worst case, and you will be compensated there.

[markopolo]

Parallax Power Supply makes the 4455TC ParaMode with TempAssure. Parallax Power Supply - 4455TC Deckmount Converter

I don't know if they are connected in anyway to Progressive Dynamics, Inc. RV and Motorhome Power Converters from Progressive

I also don't know if Progressive Dynamics has any units with temperature compensation.

I have a PD4045 all in one, AC panel & DC panel and 45 amp converter. It has the built in charge wizard but no option to add manual control pendant.

I seem to have figured out how to force the boost cycle to start - http://www.classbforum.com/forums/f5...html#post37242 - but it might have something to do with the way solar (or something else) is wired in my rig.

I say that because I can't force a different PD4045 on my bench to do the same consistently. I suspect it might check resistance or run a similar test in addition to checking voltage prior to setting the starting voltage.

Randy at Best Converter would be a good person to call.

I couldn't find much info on the Parallax 4455TC ParaMode either. Take a look at the faqs: Parallax Power Supply - FAQs

My preference in this price range would be a unit that has clear specifications. The PD unit I have has three voltages: 14.4V, 13.6V & 13.2V. I like that combo and it seems to work very well with/for my mixed bag of batteries.

I plan to measure how long boost mode lasts on the PD4045 in my van to check if it lasts 4 hours. The period boost was said to be for 15 minutes every 21 hours in the manual but is actually closer to 15 minutes every 28 hours. (confirmed several times now)

[booster]

Can't say if the companies are related, but the FAQ sure are eerily alike right down to a lot of the wording. Same writer or plagerism?

[markopolo]

Good observation.

Page 9 of this PDF:

https://d163axztg8am2h.cloudfront.ne...cf40a08c32.pdf

Shows the voltage for the Parallax TempAssure models. It looks like it's around 13.8V max at 70F.

[booster]

They also had another graph that showed a boost mode at mid 14s volts, but that was the only place it was mentioned.

There was a statement about and abundance of options (pendant maybe), but the only one listed was the temp sensor.

Very strange indeed.

[booster]

It appears to go into boost when plugged in as crank mentioned originally and then 4 hours there before float. Apparently jumpers and a pot for voltages. Here is a link to a discussion.

RV.Net Open Roads Forum: Tech Issues: Paramode Converter Voltage Increase-UPDATE_Results

Good Sam Club Open Roads Forum: Tech Issues: Parallax Paramode Converter Broke...No Workie

[markopolo]

The Samlex SEC-1245A 45 Amp 3-Stage Charger and Power Supply might do everything Crank wants:

SEC-1245A 45 Amp 3-Stage Charger and Power Supply

It has great documentation also.

[booster]

The Samlex definitely has the temp control and battery settings that Crank wants, although the charger profile and options are certainly "unique" based on the manual in the link.

Absorption set at 4 or 8 hours, and stated as timer based, but reading elsewhere would indicate it might not be timer only and those may be the maximum times. They show a bulk/absorption transition at 80% of charger capacity and a float transition at 10% of charger capacity. This is similar to what the Xantrex Truecharge did for control, as was discussed in another thread. Samlex has similar warnings about the charger staying in absorption too long if there are loads being run off the charger at the same time as the batteries are charging and recommend using a special setting that basically moves the absorption voltage to the same as the float voltage. That would prevent the over absorption time issues, but would not get the batteries recovered well at all. We are very well aware of the issue of loads on a charger based amp transition, as that is how our Blue Sea worked. This seems to be a trend in the latest charger designs as they are gravitating toward amp controlled charging. It is also easier and cheaper than using a shunt based system to read the amps right at the batteries. Unfortunately, it has some issues as we have seen, so I don't know if it is all that much better than timers or not. My guess would be that if you could set the transition amps, and not have them fixed for all applications like the Xantrex and Samlex are, you would have an advantage over timers as because you could allow for any loads you might have on to some degree, and actually get the right amps for your specific battery bank. Without the amps being settable, it gets tough to be even close to be a good match to any given system.

There also appears to be no way to force it to float or absorption, and it isn't clear if it always goes to absorption at plug in, or if it checks voltage first. The fact that they transition on amps would make it likely that they do a full charge every time. To get it to stay in absorption you would have to put a 5+ amp load on it from the coach to stay above the 10% transition threshold.

The other issue to be aware of may or may not be a problem, but is worth considering. This is "two bank" charger, but in reality it is just an "isolated bank" charger. All they do is put diodes in the output lines so the batteries can't crosscharge when they are not on the charger. For charging, both batteries share the output of the charger and all the setpoints that go with that, so you really don't charge them any different than with a single bank charger. Of course there is on glitch in this, and that is the diodes, which give a voltage drop that is based on current amount. The Samlex says they kick up the power supply setting by enough to cover the drop at full load (.2-.3 volts of drop). This would also mean that when the current drops, the voltage is going to go up by a % of the .2-.3v, which could give you high charge voltage if the 10% cutout doen't come soon enough because of load or a big battery bank. The Blue Sea had the same issue, but they had the voltage right at setpoint in the charger, so you saw a decrease of voltage at full load, and setpoint at low currents. You would never know it, though, because the displayed the voltage from before the diodes. You only saw it if you measured voltage at the outputs with a meter.

It looks like the charger makers are trying to come up with ways to get the charging more accurate by using amps, but really have trouble doing it in a lower cost unit that doesn't have user input setpoints and a shunt.

[Crank]

Wow, you guys have been busy making interesting observations and suggestions, while I have been struggling to formulate an apology for the muddle I created by confusing PD and Parallex.

You are quite correct Marco, I was indeed writing about Parallax Power Supply who makes the 4455TC ParaMode with TempAssure. Parallax Power Supply - 4455TC Deckmount Converter

I apologize for writing Progressive Dynamics (PD). I had been looking at products from both companies. There is no declared relationship between them. PD does not mention temp compensation as far as I know. I think the PD uses the charge Wiz, not the Parallax.

Wherever I wrote PD above, please think Parallax, which is what I meant to refer to!!! Anyway, I think we have moved beyone either of them.

I did look at the Samlex, but did not have time and the wisdom to consider its pros and cons: thanks for the analysis Booster!

I have just found another interesting charger, the Xantrex TrueCharge2. It seems a bit like the Samlex, but more advanced. On the Bestconverter site, click on "Selecting the correct size charger" to access more data on it. (the multibank provision has no interest to me, especially as all the batteries must be the same type if using 2 or more banks.

This Xantrex charger appears to have much better defined and sophisticated charge controls, temperature compensation and is highly configurable. Twice the cost, but perhaps worth it, especially if you are trying to protect a couple of AGM batteries.So far, after spending most of the time reading, I have not found any faults, but did find a couple of strong positive reviews. I have a few questions to answer yet and hope to call the company tomorrow. Also I don't have Booster's analytic capabilities.

It is going to take me a while to absorb and understand this flood of new information, so I may be quiet for a few days (which won't mean I'm not paying attention to any new posts. Thoughts on the Xatrex TrueCharge2 will be of great interest.

Crank

[booster]

I actually have a Truecharge2 that is a few years old, and I just looked at the new ones a little while ago because I was getting ready to sell it. I wanted to see if they had changed them. It is only 20 amps and I got it as a bench charger. At the time it was about all I could find that would equalize, and I needed that on the bench charger. I am now going to switch to using the Blue Sea I took out of the Roadtrek for on the bench because of the setable transition amps. There is another thread where someone is looking at a Truechage also.

Without going into a lot of detail, the Truecharge2 is controlled a lot like the Samlex, and does the transition to float at 10% of the CHARGER capacity, not the batteries, and the amps are not setable. The shortcomings of this setup are described in the Samlex post.

If you go with the 60 amp version or the Truecharge2, you are getting into the $500+ and probably $30 for temp sensor, range, so you other options do open up. I would make one suggestion to consider the Blue Sea 40 amp charger, at that price point. You would be giving up 20 amps of charging speed, so that may be out for you right there. I have seen recently an add for the Blue Sea at $509, but don't know if that is still a good price. Mine came with a temp sensor included so you would save that if they still do. You don't need a remote as it has a very nice screen on the charger. It would also give you full adjustability of charge voltages, time, and transition amps. The amp measurement is internal like the Samlex and Xantrex, but you can adjust the amps to allow for loads. It also closer to a real 3 bank charger rather than just diode isolated like the Samlex and Xantrex, so with a relay you can eliminate the load problem completely by using a different bank for the loads and have charge accuracy equal to the Magnums. IMO, at the same or similar price, the 40 amp Blue Sea would do a better job than any of the other 60 amp chargers you have looked at.

If you decided to go with a Blue Sea, I think I still have the 12v relay and time delay I used to put the loads on a separate bank, which worked very well with no operator input needed. They are just sitting here, so you could have them. They are very easy to wire in.

[Crank]

Thanks for the Blue Sea suggestion and offer of parts, Booster. I’m not familiar with that brand. It is next in line to read up on.

I think we need to narrow down the Amp rating and other characteristics of the charger that would best meet my needs.

I will have 2 100 Ah Lifeline batteries in one bank (plenty for my little van – I have no large DC loads) & no need of multiple battery banks.

Xantrax Truecharge-2 has a 20 and a 40 amp charger, and 200 Ah delineates choice of these two ranges. They warn about having too high an amperage charger because of battery overheating, so logically I would have to get the 20a model. I don’t know if this is a general concern. (More amps means faster charging, especially useful for a generator, which I have). They also say that use of a generator without a pure sine wave can cause overheating problems, but I have also seen comments from owners that their generator works fine with it). So perhaps these two warnings are CYA only.

Just now I looked at the Samlex SEC-1245A in a blue case listed on Bestconverter: it is in the stores but I don’t find it listed on the Samlex site. They list a UL series, e.g. SEC-1230UL (12v, 30a), a 15a, 50a & 80a, all in a yellow case, sometimes referred to as Samlex Solar). So what is the difference with the SEC-1245A? As far as I can tell, the 1245A only supports 2 battery banks and has a “half power” mode. (Discontinued?)

None appear to have temperature compensation, which is essential for AGM. If so, that eliminates Samlex, I think.

Next, I need to study the Blue Sea series.

Regards, Crank

[booster]

I think that Xantrex is putting tight limits on battery bank size because they don't want to get too big a mismatch on the float transition, which is fixed at a % of the charger size. If you have temp compensation, overheating shouldn't be an issue, even at 60 amps.

IMO, 40 amps would be fine as it is 1/5 of you battery bank capacity. Lifeline likes to have at least that much for 50% or more recharges, so good to go.

When you read about the Blue Sea, the description of the float transition by amps is a bit short and cryptic. They call it "ending" amps, but it is the same as return amps, tail amps, float transition amps, as everyone uses different terms. It is totally setable, as are all the charging voltages, which none of the others have that you are looking at.

Can't speak to the dirty generator power, as our Onan actually was very good in that respect.

[Crank]

That's encouraging news about Xantrex. I just assumed that the Onan output would be square wave: not too many generators clean up the waveform. I have no way of checking it. So the 40a Xantrex may be a good candidate after all.

Looking back at your post # 11, I see you stated that Samlex DOES have temp. Compensation. I was just unable to find it in the specifications - I looked several times: no mention of a probe either.

I'm looking forward to reading about Blue Sea when I am a little fresher - thanks for the translations in advance.

Crank

[Crank]

Booster, were you referring to the Blue Sea P12 40a and 360 Panel P12 Battery Charger LED Remote?

I'll need the remote because the charger will not be accessible. Do I need a voltmeter across the batteries (with a shunt, I think?) – there is no direct, accurate charge voltage read-out, is there?)

About $574 + $114 - marine grade construction and protection, independent control of multiple battery banks. A very impressive unit and has excellent, clear installation instructions, which means a lot to me. I’d rather pay more for a fully automated system than less for one I have to keep monitoring and adjusting. “Install, adjust and forget” would be my preference (except for watching SoC): I don’t go camping to eternally fiddle with adjustments.

You wrote “with a relay you can eliminate the load problem completely by using a different bank for the loads and have charge accuracy equal to the Magnums.” I don’t follow this: are you suggesting two banks of 1 battery each? Or are you saying that one circuit would handle the power for all loads during charging, while another handles charging the battery bank?

Is any additional precaution required against overcharging from the engine alternator? Should the monitor be located where I can see it from the cockpit, partly with a view to shutting off power from the isolator if the batteries start to overcharge?

(A lot of new concepts have been thrown at me during the last week, and while I’m learning, there are some things I can’t quite wrap my mind around yet). But I (and surely others) are enormously grateful for the time you and Marco have spend sharing your experience and wisdom. Some more time and more will become clear to me.

Crank

[booster]

Originally Posted by Crank

Booster, were you referring to the Blue Sea P12 40a and 360 Panel P12 Battery Charger LED Remote?

I'll need the remote because the charger will not be accessible. Do I need a voltmeter across the batteries (with a shunt, I think?) – there is no direct, accurate charge voltage read-out, is there?)

About $574 + $114 - marine grade construction and protection, independent control of multiple battery banks. A very impressive unit and has excellent, clear installation instructions, which means a lot to me. I’d rather pay more for a fully automated system than less for one I have to keep monitoring and adjusting. “Install, adjust and forget” would be my preference (except for watching SoC): I don’t go camping to eternally fiddle with adjustments.

You wrote “with a relay you can eliminate the load problem completely by using a different bank for the loads and have charge accuracy equal to the Magnums.” I don’t follow this: are you suggesting two banks of 1 battery each? Or are you saying that one circuit would handle the power for all loads during charging, while another handles charging the battery bank?

Is any additional precaution required against overcharging from the engine alternator? Should the monitor be located where I can see it from the cockpit, partly with a view to shutting off power from the isolator if the batteries start to overcharge?

(A lot of new concepts have been thrown at me during the last week, and while I’m learning, there are some things I can’t quite wrap my mind around yet). But I (and surely others) are enormously grateful for the time you and Marco have spend sharing your experience and wisdom. Some more time and more will become clear to me.

Crank

It is too bad the charger won't be easily accessible, as it has much better information on its screen than the LEDs on the remote.

To monitor SOC, amps, and voltage remote from the charger, you will still need a battery monitor like the Trimetric, as none of the chargers have a built in monitor until you get into the Magnum type level. The monitor will require a shunt, that you can get with the monitor kit.

The load problem fix is a kind of new thing, I think, as when I proposed it to Blue Sea they hadn't even thought about if it would work.

Currently, you would use one bank of the charger to do everything, including the charging the batteries and running the 12v power to the coach. What you change to is have one bank to the batteries and another bank to the run the coach loads. You do this to prevent the charger from thinking the load amps are going to the battery and messing up the charge accuracy.

When you separate the batteries and load on separate banks, you do create an issue, though, because the batteries and coach need to be connected, when you are not on the charger, to run the coach. That is where the relay that I mentioned comes in. It would be wired to have the batteries connected to the coach when not on shore power, and disconnected from batteries when the charger is running. The relay would control from the charger output. It sounds more complex than it is.

Overcharging from the alternator is something we have discussed many times around here, and it is good that you want to address it, as most don't. The cheapest and easiest, non automatic, system is just to mount your battery monitor in a place where you can see it when you are driving. All you need to do is watch the amps and when it gets to the low amps that indicate full, you shut off the charging from the alternator. If you van doesn't have a switch between the engine and batteries you would have to add one, or a remote controllable separator. The other options of adding smart regulators to the system are quite spendy, and IMO aren't as accurate.

[papab]

Originally Posted by Crank

I will have 2 100 Ah Lifeline batteries in one bank (plenty for my little van – I have no large DC loads) & no need of multiple battery banks.

Xantrax Truecharge-2 has a 20 and a 40 amp charger, and 200 Ah delineates choice of these two ranges. They warn about having too high an amperage charger because of battery overheating, so logically I would have to get the 20a model. I don’t know if this is a general concern. (More amps means faster charging, especially useful for a generator, which I have). They also say that use of a generator without a pure sine wave can cause overheating problems, but I have also seen comments from owners that their generator works fine with it). So perhaps these two warnings are CYA only.

Regards, Crank

I wouldn't worry at all about too much amperage. Lifeline encourages it. The problem with the truecharge is the float transition amps, as Booster has pointed out, it's too high. I bought mine thinking that would be better than a timer transition, but in hindsight I think a timer would be better. Adjustable float transition amps is the right way.

[Crank]

“The charger has much better information on its screen than the LEDs on the remote.“ I CAN put the new charger on a wall somewhere close to the batteries and get rid of the lower section of the Magnetek, using only the distribution panel. Then I can move everything around and make new space for the 2nd battery – good!


One thing I don;t quite understand: the Magnetek positive battery lead goes from the post to a terminal on a small rectangular device mounted on a wood surface. A similar lead then continues on from a second terminal into the generator.


Another wire runs from the second terminal of this device, joining the DC distribution wire harness going into the Magnetek, where it is attached to an unfused terminal. I suppose this must be the charging cable for the batteries and I would wire it into bank 1 of the Blue Sea. But I probably need to upgrade it and the rather puny wire from the mystery device (and maybe the device itself) to carry more current (8WG). The DC batteries will be about 4’ from the power source.

What is this device? I’m guessing a fuse (60a needed for upgrade).


Another, fatter wire runs from the same positive battery terminal through the floor, and surely connects to the isolator/alternator. The Econoline-style engine arrangement should make it easy to bring a loop of that line into the cab where I can add a manual switch.


I infer from the wiring I described that the generator uses the coach battery for a starting/running battery. Right? (My original Onan RV manual says it has a 360 CCA dedicated battery, but if there is one, there is no way to access it. The Onan is also stated to have a 1 amp charge circuit, but that its battery is normally charged by the vehicle.) It can also start without a coach battery if the engine is running.


To implement your ingenious idea of separating the coach load from the charging current I would presumably run a single large DC wire from the Blue Sea terminal designated Bank 2 to the old Magnetek DC section - actually to the same unfused terminal from which I removed the charger line - to serve the existing DC distribution wires, and also wire in the relay you mentioned (I don’t know exactly where).


The last step would be to remove the AC supply from the Magnetek and connect it to the Blue Sea.


(This was a test. How did I do?)


I plan to order all the equipment, cables, etc, when I am satisfied I know how to install the Blue Sea.



Crank