Recommended Chargers, Inverter/Chargers

[peteco]

There has been a lot of discussion about the best way to charge a battery and chargers. Of course it depends on what power sources are being used (120v shore, solar, generator, alternator...) and the batteries themselves (lead acid, AGM, Lithium...) A recent discussion here that got into the charging side of the battery discussion:

http://www.classbforum.com/forums/f2...html#post83239

I presently have a basic setup: two 6-volt lead acid batteries with Tripplite 750 inverter/charger in my 2006 Roadtrek. This setup has met my needs for the past 8 years but I plan someday to upgrade the system.

So I am suggesting, if possible, we try to gather in this thread our collective thoughts on the charging aspect. Please include the specific charging units you have used or are familiar enough with to recommend. Battery monitoring systems that you have experience with would also be helpful.

[markopolo]

I'll bring forward much of what I posted in the other topic:

Booster has described the best battery charging process before. My understanding of it is:

Note: Adequately sized, temperature compensated charger required.

1. Constant Current phase. The charger output is maximum amps (programmed for a particular battery banks requirements) until a voltage set-point (again programmed) is reached. This phase can be thought of as the rapid charge recovery phase and should get the batteries to about 90% SOC as quickly and safely as possible.

2. Once the programmed voltage set-point is reached the transition to Constant Voltage held at the chosen set-point until battery charge acceptance drops to around .005C (C = capacity) for new AGM batteries for example. There will be different requirements and opinions as to what rate of acceptance should be set. This is the phase that gets the battery fully charged. This phase will take longer than the previous phase even though it only accomplishes the final 10% of charging.

3. Once acceptance drops to that chosen set-point then transition to a programmed Float Voltage for maintenance / storage phase occurs.

You can see there is no place for a timer in the process. Voltage and current measurements determine the transition points. The best chargers respond dynamically to the requirements of the battery bank ensuring an expeditious and accurate return to a full state of charge.

One way to think of this is Good, Better, Best.

Good would be a multistage timer based charger.

Better would add temperature compensation and a variable timer based on what happened during the previous phase.

Best would be the charge process described in phases #1, #2 & #3 above.

The series of Tripp-Lite Inverter/Charger that Peteco has would fall in the category of Good or Adequate in my opinion. I would take care of two batteries adequately and get a good lifespan from the batteries.

The Progressive Dynamics unit and similar would also fall into that category (IMO).

If the end user is aware of the shortcomings of units in that category then they can be compensated for.

[hbn7hj]

I use a Xantrex Truechage 2 for lead acid. 40 amp is adequate for two 6 volt batteries, 60 amp model is available. Max voltage is 14.4 volts, it will not overcharge and it has an equalizing setting. You can mount it on a vertical surface due to it's flat profile.

The best charger I have is the Kisae 1230 DC to DC charger. Just a 30 amp charger but a lot of programmable flexiblty. It does not use AC power but hooking one to your engine alternator and your solar panels is what it was designed for. We use it for charging lead acid from lithium.

[markopolo]

I'll mention the Samlex EVO series as inverter/chargers that would be in the top of the Better category. They don't quite make it into the Best category (in my opinion) because they still use a timer system. The timer is not a set amount of time though.

As part of the Adaptive Charging Algorithm, a software timer will measure the time taken from the instant the unit enters the Charging Mode untill the instant the battery voltage reaches 0.3V below the programmed Absorption Voltage, then registers this time as Bulk Charge Time To and computes the Absorption Time T1 as 10 times the Bulk Charge Time To in the internal “T1 Timer” i.e. T1 = To x 10.

Examples:

If you set the Absorption Voltage to 14.4V and it takes 45 minutes to get the battery bank to 14.1V in the Bulk Charge stage then the Absorption Stage at 14.4V will last 7.5 hours.

If you set the Absorption Voltage to 14.4V and it takes 5 minutes to get the battery bank to 14.1V in the Bulk Charge stage then the Absorption Stage at 14.4V will last 50 minutes.

All the other features are great and the settings are programmable via the remote panel. It has generator input and generator autostart. You can tie in an auxiliary DC charge source of up to 50A current.

It logs the following data to an SD card: Date, Time, Gen status, Gen freq, Gen volt, Grid status, Grid freq, Grid volt, Input current, Input VA, Input watt, Output freq, Output volt, Output current, Output VA, Output watt, Battery volt, Battery current, External current, Battery temperature, Transformer temperature, Bus bar temperature, Heat sink temperature, Fan speed, Mode, Error code, Charge stage, Event

I think that a key to success with this unit is choosing the best charging amperage (bulk charge current) as that greatly affects the “T1 Timer". Looking at the spreadsheet logs after few test cycles should show when you've got the setup right.

The bulk charge current for the EVO-2212 is programmable from 0 to 100A DC and the EVO-3012 is programmable from 0 to 130A.

[booster]

A lot depends on how much you want, or are willing, to spend for charging equipment. On the higher end, and from our personal experience, the Magnum MS2000 with the ARC50 remote, shunt, and better temp sensor is tough to to beat. For two six volt batteries it would be overkill on capacity for wet cells, but the output can be turned down far enough, I think, as you would want about 30 amps max to take good care of wet cells. It would be oversize for AGM batteries also, but depending on the brand not very much. Lifeline is now recommending .4C charge rate, especially if the discharge is 50% or more. For 220ah of six volt batteries that would be 88 amps for the 100 amp Magnum so only minor turn down. We have found only one irritating thing in the way it works, and luckily there is an easy work around for it in use. When you plug into shore power it checks battery voltage to determine if a a charge cycle is needed, which is what nearly all "smart" chargers do. Unfortunately, voltage is a horrible indication of SOC near the high end, especially if you have just been driving and have surface charge showing, which will put it directly to float. This can keep it from doing a full charge to amps based fully charged like you want for long battery life. Any charger that is doing amps based charging should always run a charge cycle when plugged in for the above reasons. The direct to float is to prevent overcharging on top of full or near full batteries with timer based chargers, but if the unit is amps based it doesn't matter because if the batteries are already full as it will run a minute or two, see the low amps and go to float. If it doesn't see the low amps, it will complete the charge. I just look at the remote whenever we plug in, and if it goes to float I can easily push a couple of buttons to manually start a charge cycle. One nice feature of the ARC50 remote is that it includes a battery monitor so you don't need a separate one.



In the midrange pricing, IIRC correctly there are a few chargers that transition to float based on amps, but they only have a few choices for the amps and any coach loads will mess up the transition because the amps are measured inside the charger, not at a shunt measuring only battery amps. The Zamp appears to do it that way, maybe Samlex, and I am sure some others. Blue Sea has a charger that is 40 amps and has settable amps, but again the loads will mess it up because of internal measuring. The Blue Sea is a 3 bank setup so the loads can be moved to another bank to get around the issue with a relay and some creative wiring. We ran our Blue Sea that way for quite a while successfully.



Also midrange would be the Progressive Dynamics chargers with the optional pendant. When coupled with a battery monitor, you can get very good charging with them but you have to select the stages manually to do it off of the pendant. The PD chargers are the only midprice units that I know of that allow charging stage forcing. Their major shortfall is no temperature compensation.


Most of the others out there are pretty similar timer based models and would similar to Tripplite. As Marko mentioned, you may get lucky and have your batteries, charger size, and use patterns line up well and get good life from your batteries, or you could wind up with quite short life if things don't line up well. A battery monitor is a necessity for most folks with this type of charger, IMO, unless they are willing to take what they get for battery life (might be good or bad) and don't want to mess with knowing SOC or doing any upgrades.


Another thing to point out, I think, is that you are much more likely to overcharge you batteries with van alternator than from any of the smart shore chargers. I think a lot failed from overcharge batteries get blamed on the shore chargers, but are really from the alternator charging. This is another good reason to have a battery monitor, especially if you can see it while driving or have someone check it periodically. You will be able to see the amps going to the batteries so you know when they get full and you should shut off the alternator charging to the coach. A manual override charge relay works well for the disconnect. Blue Sea makes a very nice on in both manual only and combo manual and auto modes.

[markopolo]

I think Booster's full setup is described here: http://www.classbforum.com/forums/f8...rade-4007.html

The Magnum MS2000 100A + ME-BMK + ME-ARC50 combo would definitely be in the category of Best inverter/chargers (in my opinion).

[GeorgeRa]

The choice of PWM (Pulse Width Modulation) or MPPT (Maximum Power Point Tracking) is important regarding solar charge controllers in addition to charging intelligence addressed above. PWM controllers are still less expensive but MPPTs are coming down in price. With higher voltage panels MPPT is practically a must, but with lower voltage panels in some situation like for example low light conditions MPPT controller will harvest more.
I use Mornigstar 45 TS MPPT solar charge controller and Magnum MMS 1012/ME-ARC and am contemplating about adding Kisae DC-DC 1230 for engine alternator charging. So, potentially 3 devices to charge batteries, I wander if a different combo wouldn’t be better for AGM batteries, PV/Shore/Alternator charger and a standalone inverter or all together in one unit.

https://www.youtube.com/watch?time_c...&v=K7NWpxxEB9o

[booster]

Originally Posted by GeorgeRa

The choice of PWM (Pulse Width Modulation) or MPPT (Maximum Power Point Tracking) is important regarding solar charge controllers in addition to charging intelligence addressed above. PWM controllers are still less expensive but MPPTs are coming down in price. With higher voltage panels MPPT is practically a must, but with lower voltage panels in some situation like for example low light conditions MPPT controller will harvest more.
I use Mornigstar 45 TS MPPT solar charge controller and Magnum MMS 1012/ME-ARC and am contemplating about adding Kisae DC-DC 1230 for engine alternator charging. So, potentially 3 devices to charge batteries, I wander if a different combo wouldn’t be better for AGM batteries, PV/Shore/Alternator charger and a standalone inverter or all together in one unit.

https://www.youtube.com/watch?time_c...&v=K7NWpxxEB9o

It is interesting to see a 3 source charger, but as with everything there would plus and minus, I think. Minus side would be if it died you lose all charging capability. A plus or minus would be the quality of the charge control. Is the charge control of the 3 way better or worse than standalone versions for getting batteries full without or under charging? If you have a Magnum shore charger and a Blue Sky solar controller it would probably be less precise. On the alternator would it be better or worse than a Balmar smart regulator or a Sterling battery to battery charger? Same comparisons could be done against stand alone pieces in all price ranges.



The current Magnum and Outback chargers both now have integrated solar controllers available IIRC, so that would be the high end way to handle two of the three. For most vehicles, the alternator voltages are close enough to absorption voltages for coach batteries to go direct and just watch a monitor and shut off the coach charging when full.

[cruising7388]

Originally Posted by peteco

There has been a lot of discussion about the best way to charge a battery and chargers. Of course it depends on what power sources are being used (120v shore, solar, generator, alternator...) and the batteries themselves (lead acid, AGM, Lithium...) A recent discussion here that got into the charging side of the battery discussion:

http://www.classbforum.com/forums/f2...html#post83239

I presently have a basic setup: two 6-volt lead acid batteries with Tripplite 750 inverter/charger in my 2006 Roadtrek. This setup has met my needs for the past 8 years but I plan someday to upgrade the system.

So I am suggesting, if possible, we try to gather in this thread our collective thoughts on the charging aspect. Please include the specific charging units you have used or are familiar enough with to recommend. Battery monitoring systems that you have experience with would also be helpful.

A lot of attention is paid to charging protocols but what doesn't seem addressed is how the converter in any particular charger allocates its output between converter 12V loads and the battery charger. Apparently, some chargers assess the coach demand and prioritize it over the battery demand. For example, if the battery charger is capable of delivering 70 amps but the converter demand is 30 amps, the charging will be limited to 40 amps. But if there is little or no coach load demand it will deliver the full 70 amps to the battery if the charging profile demands it.

But they apparently don't all have the capability of making this assessment and adjusting charging output accordingly. The Power inverter/converter provided by Roadtrek doesn't, even on the Etreks. So, what they do to address this is to program the charger limit to about 50% of its maximum charging capability. Our coach has 800ah of lithiums with a 70 amp Powerstar battery charger, but the factory has programmed the charger to a maximum of 36 amps. This might be acceptable for an AGM installation, but for well discharged lithiums, it doesn't cut the mustard.

[booster]

Originally Posted by cruising7388

A lot of attention is paid to charging protocols but what doesn't seem addressed is how the converter in any particular charger allocates its output between converter 12V loads and the battery charger. Apparently, some chargers assess the coach demand and prioritize it over the battery demand. For example, if the battery charger is capable of delivering 70 amps but the converter demand is 30 amps, the charging will be limited to 40 amps. But if there is little or no coach load demand it will deliver the full 70 amps to the battery if the charging profile demands it.

But they apparently don't all have the capability of making this assessment and adjusting charging output accordingly. The Power inverter/converter provided by Roadtrek doesn't, even on the Etreks. So, what they do to address this is to program the charger limit to about 50% of its maximum charging capability. Our coach has 800ah of lithiums with a 70 amp Powerstar battery charger, but the factory has programmed the charger to a maximum of 36 amps. This might be acceptable for an AGM installation, but for well discharged lithiums, it doesn't cut the mustard.

On a Roadtrek system, I thought the in and out of the battery were isolated when charging, with the coach running off the output from the batteries?



To separate the battery charging from the coach loads, the charger would have to have two outputs in a normal setup, with one prioritized over the other. I have never personally seen any such setup, but they may exist. I would guess the only reason to prioritize the coach would be if you had critical stuff that couldn't stand lowered DC voltage.



We have a 100 amp charger with one output. The power goes to whichever place has the highest acceptance of it. If the battery would take 70 amps by itself and the coach 40 amps, the voltage just drops until the amperages go down to a level totally 100 amps. Which loses the most will be dependent on the impedance of the differing destinations.

[GeorgeRa]

My Morningstar solar charge controller has a separate output for loads but I wired all loads to the battery bank.

[markopolo]

Originally Posted by cruising7388

A lot of attention is paid to charging protocols but what doesn't seem addressed is how the converter in any particular charger allocates its output between converter 12V loads and the battery charger. Apparently, some chargers assess the coach demand and prioritize it over the battery demand. For example, if the battery charger is capable of delivering 70 amps but the converter demand is 30 amps, the charging will be limited to 40 amps. But if there is little or no coach load demand it will deliver the full 70 amps to the battery if the charging profile demands it. ............................

You'd have to have some 12V circuits completely isolated from the battery for what you describe to even be possible. That would be unusual and seems very unlikely. The words converter and charger are synonymous as they apply to typical setups. Those isolated circuits would not run from the battery when off grid.

Is it possible that you are referring to how an inverter charger apportions grid input (AC) between the pass-through and charger?

[booster]

Originally Posted by markopolo

You'd have to have some 12V circuits completely isolated from the battery for what you describe to even be possible. That would be unusual and seems very unlikely. The words converter and charger are synonymous as they apply to typical setups. Those isolated circuits would not run from the battery when off grid.

Is it possible that you are referring to how an inverter charger apportions grid input (AC) between the pass-through and charger?

I think you are on to something with the last sentence.



Probably referring to AC limiting to the charger section to preserve AC for the coach. Per the Magnum MS2000 manual

Shore Max/Input Amps:This setting ensures the inverter AC loads receive the maximum current available from the utility or generator power. When the total current used to power the AC loads and charge the batteries begins to approach the Shore Maxsetting, the current that was used for charging the batteries will automatically be reduced

[avanti]

Originally Posted by booster

I think you are on to something with the last sentence.

Probably referring to AC limiting to the charger section to preserve AC for the coach. Per the Magnum MS2000 manual

Hmmm...
Well, I guess the logic of the situation is the same for DC as for AC: A dicharged battery looks like any other load on the DC bus, no? So, such a feature could serve to prevent overloading the DC circuits when other large loads were present. So, I'm not sure it wouldn't make some sense in principle. It would be implemented by providing a dedicated "house load" output from the charger. I suspect that the reason that this feature is uncommon is because few rigs have high-load DC devices, so the situation tends not to arise. An exception might be a DC air conditioner.

[booster]

Originally Posted by avanti

Hmmm...
Well, I guess the logic of the situation is the same for DC as for AC: A dicharged battery looks like any other load on the DC bus, no? So, such a feature could serve to prevent overloading the DC circuits when other large loads were present. So, I'm not sure it wouldn't make some sense in principle. It would be implemented by providing a dedicated "house load" output from the charger. I suspect that the reason that this feature is uncommon is because few rigs have high-load DC devices, so the situation tends not to arise. An exception might be a DC air conditioner.

I would agree, plus if it were wired that way it would have to connect the two outputs when not on AC. You also would not have the battery available to help out if you really had a big DC load in the coach for some reason.

[cruising7388]

Originally Posted by booster

I think you are on to something with the last sentence.



Probably referring to AC limiting to the charger section to preserve AC for the coach. Per the Magnum MS2000 manual

I believe this feature was on both the Magnum and the Prosine 2.0 units I had. So it appears that I've described an accurate result but for the wrong reason.

In any event, the Powerstar is bereft of this feature and consequently you end up with a defined maximum charge rate of about half the charger design capacity.

[markopolo]

I just was looking in the Signeer manual that was posted previously on the forum: https://www.sigineer.com/wp-content/...-2017-July.pdf

page 20

It is better to shut everything off after low voltage trip than to leave your load in the risk of fire. Nobody wants to return home, finding house surrounded by fire trucks, and naughty neighborhood kids toasting hot dogs against his house.

That's pretty specific ..........


Sorry to drift off topic.

[hbn7hj]

Dealing with house load:

I guess I have an advantage with the hybrid system. If the house load causes problems I change it to the other battery bank. I always move the load to the lithium bank when charging the lead acid with the DC to DC charger so it can do it's thing properly. The Xantrex is too dumb to know the difference.

[markopolo]

Originally Posted by markopolo

I'll mention the Samlex EVO series as inverter/chargers that would be in the top of the Better category. They don't quite make it into the Best category (in my opinion) because they still use a timer system. The timer is not a set amount of time though. ................................

I have to update that. Booster's post here - http://www.classbforum.com/forums/f2...html#post83368 - led me to firmware upgrades for both the EVO remote and the Samlex EVO unit. You now have the option of several charging profiles including exiting absorption based on amps and that puts the Samlex EVO firmly into the top tier of inverter chargers in my opinion.