Batteries, chargers, profiles etc

[booster]

Lately we have been seeing quite a bit more interest and questions related to batteries, both type and brand, and chargers of all kinds. I think this is very a very good thing because a lot of the information floating around the internet is less than stellar, IMO, and information from the manufacturers is often extremely biased and full of claims that aren't not exactly true, again IMO. We have seen, many times in the past and now, statements made about how well a certain charger worked for people and how perfectly it charged batteries. I think comparing their observations to the charging profiles would be very beneficial for all of us.



I will put a few charger profiles and a couple of Lifeline charging instruction statements for reference. The chargers are ones that I am familiar with and have been mentioned in other discussions. It would be desirable for anyone who has a charger manual that gives detailed charging profiles and instructions to put a scan of them in a post so we can get more of cross section of brands and styles. Same for batteries.



This thread is meant to be in addition to the currently running battery selection one and petco's charger recommendation one as a place to collect information and discuss it without garbaging up the other discussions.



There likely will be lots of personal opinions on much of this stuff, which is great, and I would also encourage anyone who has battery monitor data to back up opinions to post the monitor data and monitor settings, as that can be critical for others to repeat the results.


Here are the Lifeline battery charging instructions for their AGM batteries. The don't show a profile chart in the manual any more.







Here are add on instructions to maximize battery life for deep discharge situations.






Here is the Magnum ARC50 remote charging profile when set to using a final stage of float. Note the options available in the note in the center of the graph for the transition to float. This is the critical piece of the charging profile for long battery life. All of the options are fully setable, and using amps is the preferred method IMO, and will meet the above Lifeline charging requirements completely.

[booster]

One of the chargers mentioned in the other discussions, and very often in the past, is a Progressive Dynamics charger with a Charge Wizard pendant.


Here is the charging profile for the Charge Wizard. Note the 4 hour, non adjustable, absorption time, as this is what can make a charger over or under charge batteries. The PD chargers also don't have temp compensation, so these are voltages you will get even at high and low temp where a volt or more difference could be required to protect and charge the batteries. The big plus is that if you watch what the charger is doing via a battery monitor, you can force it into whatever charge stage you want, preventing over or under charging.




Another unit mentioned recently was the Zamp digital display solar controller. Here is the charging profile from the Zamp manual.





Here is what Zamp says about the transition from absorption to float. Note only two amp settings at .5 and 1.0 amp, which is very low, and also only 4 hours of maximum absorption time which appears to be non settable. While controlling by amps is the best, you need to be able to set the correct amps in the charger and allow it enough time to get there, which I don't think would happen with the Zamp. The Zamp can have temp compensation, a plus.

[booster]

Here are a couple of battery charge profiles from the Trojan battery manual.


This is for their true deep cycle batteries, which are pretty much the standard choice for lots of folks. The list charge rate at a desired 10-13% of capacity for wet cells. Note the fairly high charge voltage and the "full" battery current of 1-3% of capacity. They also show a "mini equalization" stage at the end of every cycle, which is becoming more common with manufacturers, even for AGM batteries.








Here is the AGM curve for the Trojan versions, which seems to be similar to most of the the charger voltages for AGMs. The recommended charge current for them is 20% of capacity. Note the "full" charge current of c/200 or .5% of capacity, which is the same as the Lifelines.






As you will find for nearly all battery manufacturer desired profiles, there is no mention of charge times, except that it will vary with how deep the discharge is. The desired charge cycle is controlled only by voltage and amps.

[booster]

Here is what IOTA says about the charge profile they get with their optional "Charge control module" which is an addon like the Charge Wizard for PD.

BULK STAGE
- During this state, the charger will operate either at Full Current output or Constant Voltage output
depending on the discharged state of the battery. A discharged battery will dictate the voltage and force the charger into constant-current operation. As the battery charges, the charger transitions to a constant-voltage operation.This BULK STAGE will continue for either 225 minutes or until the battery voltage reaches the “High Trigger” value (whichever occurs first). At this point, the BULK STAGE will operate for another 15 minutes before switching to the
ABSORPTION STAGE.


ABSORPTION STAGE
- This state is limited to 240 minutes (4 hours) during which the charger will operate either at Full Current output or Constant Voltage output depending on the discharged state of the battery. During Full Current output, the charger is providing its full current rating and will slowly increase the battery voltage to the “Absorption
Stage” voltage. At the end of the 240 minutes, the charger will revert to the FLOAT STAGE.


FLOAT STAGE
- This charge state holds the batteries at Constant Voltage for a period not longer than seven days. During this state, the charger not only floats the batteries, but it can also provide load current up to its maximum rating for other loads without depleting the battery capacity. The FLOAT STAGE will end when either the battery voltage drops below the “Low Trigger” point or at the end of seven days when the IQ4-X initiates an equalization stage to remove sulfate layers from the battery plates. In either situation, the unit exits the FLOAT STAGE and enters the BULK STAGE.

This seems to indicate that the IOTA uses the very common 4 hours, unsettable, of fixed, timer based, absorption time. What this meas is that that if you batteries were below about 20% discharged they will be undercharged by some amount, and if they were full when you plugged in (like from driving or solar) they will overcharged at full voltage for 4 hours.


Both of these conditions is bad for you batteries, and depending on your use patterns could shorten their life a lot.



A typical bad stacking of events might be that you are on shore power all night and then off the get breakfast. You come back and plug in and it chargers your full batteries for 4 hours of overcharge. You then go off for hike and come back and plug in and get another 4 hours of overcharge. Then you drive to the dump station and again plug in when you return and get another 4 hours of charging. By then you got 12 hours of full charge voltage overcharging time on your full batteries in just one day. Especially AGMs will not like that, wet cells will use more water but survive a bit better. This is very similar to the Progressive Dynamics profile but with no manual over ride available.


It is possible they check for full batteries before starting the charge, but I didn't see anything about that, or might have missed it. If they did do that, you would eliminate the overcharging situations in most cases, but would be trading that improvement for having more undercharging events.

[booster]

Here is copy of a statement for the EVO-RC-Plus smart remote for some of the Samlex inverter chargers.

ABSORP EXIT AMPS (Table 4.3, Screen No. 20)
Parameter “ABSORP EXIT AMPS” is used to set the value of the charging current at which the charger will exit the Absorption Stage and transition to Float Stage when the following "CHARGING PROFILE" option is selected.
• 2=3 Stage Type 2
Programmable range is 0 – 20A. Default value is 4A.

This would indicate that the charger is measuring the amps out of the charger and can be set to end the absorption stage based on amps, which is a good thing. The problem comes in that it is also measuring any and all coach 12v loads that are running, which can severely mess up when the charger transitions to float. 220ah of AGM batteries would be at 1.1 amps to get the .5%C that Lifeline wants, so even having light on would mess things up. If you have solar at the same time, the charger will see lower than the amps it should and stop early, if you have just loads on the charger might never go to float until the absorption timer runs out.


This is an inherent issue with any charger that measures the amps internally, and Samlex even mentions that using their "adaptive" automatic timer based algorithm will get messed up if loads are on while charging.



The Blue Sea chargers have a similar issue, as they to measure the float transition amps internally.


I would think that any charger with an algorithm that checks the bulk charging time to calculate the absorption time without measuring the amps would have the same issues if any loads are on. In the real use world, this would make the more sophisticated algorithm chargers very in accurate in an RV unless you had multiple battery banks that you could charge one at a time with the loads on the other bank.


This all shows the importance of measuring only the amps to the battery if you are going for the best in charging control. If there isn't a shunt to do that measuring, it gets very difficult to do. I did manage to do get the loads isolated on our Blue Sea charger when we had it, but that setup will only work on a multibank charger that measures the amps separately to each bank, and I think Blue Sea is the only one that does that.

[booster]

It appears some of my attachments disappeared into cyberspace, these are from the first two posts.


The Lifeline profile text explaination







Here is the deep discharge adder for Lifeline





Here is the Charge Wizard profile





The Zamp profile





If anything else is missing, let me know, as the originals did show here on my desktop, but not laptop, but do now show.

[markopolo]

Thanks for the info on the new Samlex remote. I saw it on their site but it seemed to only meant for use with the new F series. The manual shows that it can be be used with other EVO models.

The “ABSORP EXIT AMPS” is a nice addition as long as the user is aware of the issue with loads and or inputs that Booster points out. It appears that you have to choose either the ending amps or the adaptive profile. Maybe the next iteration will let you choose both so you still have the protection of the timeout forcing the exit from absorption stage.

If you run solar through the Samlex aux DC inputs I think it might be sufficiently aware of the input to factor it into the the charge profile.

[booster]

We lived with the load affecting the transition amps of quite a while before I modified the Blue Sea charger to move the load so it didn't mess it up, and while I would say it is better than no amp control, you only have a couple of options of how to handle it. It gets particularly hard if you have a separator and power going to the starting battery if you don't have an isolated multibank charger.


* You can add increase the setting enough to always allow the charger to go to float when you hit the load plus what the batteries are using, it will not let the batteries get all the way full a lot of the time.


* If you have a battery monitor that is measuring the battery amps, you can just check it occasionally and see when the amps to to the transition amps plus you minimum load like detectors. When you get there, shut off the other loads for a couple of minutes and the charger should go to float.


* Only plug into shore power at night when you can more easily have a consistent load that you can allow for.


All will work to varying degrees, with the last two being better than the first, but all won't be perfect.



Because of the absoption timers that look like you can piggyback onto the amps shutoff, you at least get out of absorption eventually, and it has temp compensation, so for those reasons would probably be a bit better than running a Progressive Dynamics unit manually off a monitor. Option 2 would be similar to the PD, but with less hassle, I think, but not a lot. The temp comp is a big deal in the difference between the two units.

[markopolo]

How did you move the load for the Blue Sea charger?

Looks like there are 5 profiles for the Samlex now. Two are for lithium. The other three are:

0. Adaptive
1. Set absorb time
2. Set ending amps

I can get the updated firmware for my unit. I think ending amps is the way to go for storage at home. I'm not sure what's better for in use charging. I have to think about it. You can save settings to SD card so it's fairly easy to have a few profiles ready to load.

How does the Magnum setup accomplish accomplish ending amps charging without loads affecting it?

[booster]

The Blue Sea charger has been mentioned a few times, as it does measure and control the float transition from amps, measured internally, but it has a separate amp reading and setting for each of it's 3 banks.


You can make the Blue Sea accurately charge from the amps to the coach batteries only if you are willing to do a bit of extra wiring and add a time delay relay circuit (I used a solid state timer relay and powered a bigger capacity relay coil with it).


To do the setup:


* Wire the coach batteries to bank 1 and the normally closed contacts on the large capacity relay.


* Wire the "in" of the time delay relay and the normally open contacts of the big relay to bank 3 on the charger.


* Wire the "load" of the time delay relay to the coil + on the big relay


* Wire the common of the big relay to coach distribution panel and starting battery separator (if you want both way charging and have an automatic separator).


* Wire the big relay coil - to ground.


The way it should work when you use it


* When on batteries the charger is off the battery power goes through the normally closed relay contacts to the coach. Neither of the relays is activated.


* When you plug into shore power,


1. The charger does a check to see if it sees a battery, and if it does (it will see the coach batteries connected to it) it will initiate charging for all 3 banks whether they have anything on them or not.


2. Once the time delay relay times out, it will activate the coil of the large relay and switch the coach batteries to the loads off, and switch on the output of bank 3 to the loads to run them.



The coach batteries are isolated on bank 1 at this point, so you can have the float transition amps set to exactly what you want and get exact full with no overcharge.


When you shut unplug shore power, the charger goes off, the relays deactivate and you are back running on the batteries.


This only works with the Blue Sea because it has the correct set of features on it and will maintain the right voltage on all 3 banks if just one of the banks has a battery in the circuit.


You need the time delay because when the charger does it's initiation check it will fault out for the test signal going through a big relay coil. The solid state, low power, time delay relay does not run any current until it times out, so it allows the charger to get though the startup tests.

[booster]

Here is some information on a Xantrex Freedom pure sine wave inverter charger. It appears some things have changed on them from older models.

Here is their generic profile diagram





And here is a chart showing that they do use amps for the transition to float.







The unit does appear to have a custom profile capability so you could set any charge voltages and you want, plus the normal supplied profiles.


Best guess fro the profile is that the 5 hours shown for absorption is the maximum timer setting, as they indicate in the chart that they transition based on amps and I didn't see that you could turn off the amps and use only timer. 5 hours is a bit too short to get totally full charge but probably good because the loads will mess up the amps measuring.

There appear to be only two settings for the transition to float amps at 2 and 5 amps. While better than some others that us fixed values or % of capacity, these are still pretty high for smaller battery banks and AGMs. You would need about 400 ah of Lifelines for the 2 amps to be on spec and 1000ah for 5 amps. Wet cells would match better as the 2 amps could be OK for 100-200ah of wet batteries.

As with most of the other chargers that use amps to transition, the Xantrex is measuring the amps inside the charger, no shunt, so any loads or solar are going to mess it up badly, just like with so many of the other chargers.

The unit also does does not appear to have a temp compensation option, which is a big downside.

[booster]

This is for the Aims LF series pure sine wave inverter chargers.


Here is their charge profile





And here is the profile description.





This is a charger that is using a "calculated absorption time" to determine how long to stay in absorption before going to float. They chose to use 10X the amount of time it takes to get from charge starting to .3v under absorption voltage, starting that time when bulk ends after going up the last .3v. They have minimum of 1 hour and a max of 10 hours. Based on what I have seen in our systems, I think it may only be close to correct at a particular charger output size to battery bank size ratio plus only within a quite small range of depth of discharge. Loads will have some affect o the accuracy, but not as much as with the units that use amps measured in the charger to go to float. My guess would be it would be more likely to undercharge than overcharge, which is generally the way most chargers work because battery damage is slower rather than faster as it would be from overcharging.


The unit does appear to have temp compensation avialable.

[markopolo]

The Aims unit appears to lack custom programming. You're stuck choosing between the various pairings of absorb & float voltages. Basically that means you have to pick a battery that fits one of the profiles. You'd think one of the pairings would be 14.4V & 13.2V or 14.4V & 13.4V but sadly those are not options in the manual.

-------------------------

The Xantrex Freedom SW does appear to come with a temperature probe included in the package. If you choose to not use the probe then you can alternately choose a setting of cold, warm or hot.

Setting the battery bank size to zero disables the exit current function.
Absorption time can be set from 1 to 8 hours.

Exit current at 2% of battery bank capacity can likely be manipulated by setting the bank size to get the exit amps you desire rather than the actual capacity of the bank.

--------------------------------

lot's of good info in this topic

[booster]

Originally Posted by markopolo

The Xantrex Freedom SW does appear to come with a temperature probe included in the package. If you choose to not use the probe then you can alternately choose a setting of cold, warm or hot.

Setting the battery bank size to zero disables the exit current function.
Absorption time can be set from 1 to 8 hours.

Exit current at 2% of battery bank capacity can likely be manipulated by setting the bank size to get the exit amps you desire rather than the actual capacity of the bank.


I just went back and looked at the Freedom XC series and that had the 3 stage temp compensation, which is kind of not very good. It showed the transition amps at 10% of what the charging current was set at with a 2 amps minimum. Didn't see any battery bank size setting on it.


--------------------------------

lot's of good info in this topic

I think we must be looking at different models somehow, or I am just going crosseyed from reading to many pdf manuals


http://www.xantrex.com/documents/Inv...Rev-C)_ENG.pdf


I couldn't find any information on the temp sensing, bank size setting, or the 2% of capacity, only the charts posted. I need to go back and look again at the install manual, but if IIRC it referred back to the operation manual for the settings.


Went back again and checked the Freedom SW with the SCP remote on it, and then I found the specs you gave, with programmable by degree temp comp. By manipulating the bank size it does appear you could get most any transition amp setting you would like. It appears it would, however, be measured in the charger unless there is a way to tie it to a Xantrex battery monitor, which would make sense and give a much more usable setup so the loads wouldn't mess it up.

[markopolo]

That's the lighter duty unit (IMO).

I was looking at this one: Inverter Charger | Freedom SW Inverter/Charger | Xantrex

[booster]

Originally Posted by markopolo

That's the lighter duty unit (IMO).

I was looking at this one: Inverter Charger | Freedom SW Inverter/Charger | Xantrex

You typed faster than I did !

[markopolo]

Thanks again Booster for posting about the new Samlex EVO charge profiles. I updated the inverter/charger firmware and also the remote unit firmware today.

The newer remote has a display of 4 lines of 20 characters each and my older remote has a display of 2 lines of 16 characters each but the new remote firmware works fine on it. I gained the 5 new charge profile options.

It seems that the base loads in this RV are around 1.6A for detectors and bi-directional relay etc. Because of that, I set exit amps at 4A for the approx 440Ah battery bank. I'll monitor & adjust as needed.

Also gained by the new remote firmware is the option to set the inverter/charger to charge only. That's a useful option when plugged into grid power for an extended period. That option disables the inverter so loads like the fridge, electric heat or air conditioner won't automatically transfer to the inverter if the grid goes down or the pedestal breaker trips. It's a good option to enable when you are away from the RV and don't want those loads to draw on the battery bank.

[booster]

That's good that the latest updates work well on your older model Samlex, too many companies don't seem to care about that. I like the Samlex stuff, as they seem to be very good products at a good price point compared to many others.


This has been a very interesting research adventure for me, as I haven't done a similar one in several years, back when I was trying to decide on an inverter/charger for the 440ah AGM conversion project.


What I seem to be seeing is that there still are quite a few straight timer models like the PD and Tripplite at the lower end of the scale, but they look to be disappearing from the middle and upper middle range products. The middle used to have lots of products that touted their "revolutionary, proprietary, algorithms that always charged everything wonderfully, but those do seem to be fading out and are being replaced by various versions of chargers that do the float transition based on amps, but with internal to the charger measuring of the amps. When I got our Blue Sea charger 7 or so years ago, I think it may have been about the only one around that did that kind of transition with internal amp measuring. At the time, none of us here even knew that amps was the way to go, and there was a long discussion as how and why it was good or bad. It is odd to me that none of the amp based chargers even have the option to measure the battery amps instead of internal, as that solves all of the load and solar based inaccuracy of the internal measurement.


Hopefully, when we do this all again in a few years they will have gone the next step to external measurement. These days, you don't really even need a shunt to do, so you can save all the big cable wiring on the negative only and twisted pair signal wires and go with a simple inductive loop on either the positive or negative battery cable.


As I mentioned earlier, I am surprised that Xantrex hasn't done something with tying their shunt based battery monitor to their amp based chargers, as they already have their Xanbus system for the other parts done.

[markopolo]

I'm thinking that ending amps would be the way to go when charging lithium batteries when you want to get them full. It's not critical that they get full but there may be times where having maximum capacity available is desired.

-----------

I'm guessing the reason you'd want to hold the absorption voltage beyond when the current flow drops to the chosen exit point would be be so that all batteries in the bank get very close to being equally charged.

I need one more new option in future firmware -> Exit Amps Hold time!

I might run a couple of adaptive algorithm charge cycles throughout the year just to ensure that balancing occurs.

[booster]

Originally Posted by markopolo

I'm thinking that ending amps would be the way to go when charging lithium batteries when you want to get them full. It's not critical that they get full but there may be times where having maximum capacity available is desired.

-----------

I'm guessing the reason you'd want to hold the absorption voltage beyond when the current flow drops to the chosen exit point would be be so that all batteries in the bank get very close to being equally charged.

I need one more new option in future firmware -> Exit Amps Hold time!

I might run a couple of adaptive algorithm charge cycles throughout the year just to ensure that balancing occurs.

Early on in the lithium charging shakeout of how to charge them there was a bunch of chatter from the manufactures about charging to ending amps IIRC. They then changed to wanting to keep some head space at the top of charge for longer life. Since they were stopping either at the knee in the charge curve where voltage started to rise quickly, or in the steep slope of voltage and current change I think they just found that voltage was easier to build equipment for. I doesn't really matter much where you stop, it appears, as long as they aren't totally full, as being partially discharged is OK for lithium.


I don't think that the Magnum has a setting for the hold time at ending amps, but if you have a Trimetric battery monitor I am pretty sure it does but they call it something else. As part of the "proving" programming to trigger the fully charge light on the Trimetric you put in a minimum and minimum amps setting that have to be met at the same time. They do it that way to take out the "noise' of voltage and current small variations that always happen in the real world, mostly from turning stuff on and off or the sun going behind clouds for solar. I am sure all of the chargers that use amps have a time required also, but it doesn't seem to be settable on many, if any. It is pretty easy to do manually with a some of chargers like a PD with Pendant or ones that have multiple profiles that include a fixed voltage one, but you have to make sure you don't forget it.