New Lead Acid Batteries; Charge & Monitor Upgrade?

[markopolo-ClassB]

I thought B4 controls the max charging current: 45 amps (high setting) or 11 amps (low setting).

Yes, it does that. I was wondering if it additionally affects the set point for the transition from absorption to float. I think exiting absorption at 10A as shown in your chart is premature. I thought that it is possible that the low setting might have a lower set point for the transition from absorption to float. 2A or even 5A would be better than 10A IMO.

 

[peteco]

I just measured the alternator charge numbers. The batteries (house and chassis, on an isolator) are essentially fully charged after being hooked up to the Tripplite for a day.

At engine start / after a couple minutes:
- Alternator: 24 amps / 23 amps
- Chassis Bat: 20.5 amps/20 amps
- House bat: 3.5 amps / 3 amps

Engine speed caused charge amps to go up only about am amp or less.

Voltage: 14.2v

I don't recall what the alternator voltage drops to after driving for a while. I seem to recall the Scangauge in the high 13v range. I will check that next time I drive it.

 

[SteveJ-ClassB]

This meter does measure total power used, the number on the lower right is watt hours. I use two of these to measure in and out. Hokey? Yes. But they do serve my needs just fine in a low budget way.

 

[booster]

I just measured the alternator charge numbers. The batteries (house and chassis, on an isolator) are essentially fully charged after being hooked up to the Tripplite for a day.

At engine start / after a couple minutes:
- Alternator: 24 amps / 23 amps
- Chassis Bat: 20.5 amps/20 amps
- House bat: 3.5 amps / 3 amps

Engine speed caused charge amps to go up only about am amp or less.

Voltage: 14.2v

I don't recall what the alternator voltage drops to after driving for a while. I seem to recall the Scangauge in the high 13v range. I will check that next time I drive it.

If the house batteries were taking 20+amps, and it continued more than a couple of minutes over 10 amps, it would very likely indicate that the

tripplite did not have the batteries full. I would expect two wet cells to accept somewhere under 3 amps or so when new and totally full


Good information to know.

 

[peteco]

If the house batteries were taking 20+amps, and it continued more than a couple of minutes over 10 amps, it would very likely indicate that the

tripplite did not have the batteries full. I would expect two wet cells to accept somewhere under 3 amps or so when new and totally full

Good information to know.

So the 2 new house 6 volt batteries were accepting what would be expected. I was surprised the chassis battery was taking 20 amps, as I would have thought it too was fully charged from the Tripplite through the isolator.

 

[peteco]

I just measured the alternator charge numbers. The batteries (house and chassis, on an isolator) are essentially fully charged after being hooked up to the Tripplite for a day.

At engine start / after a couple minutes:
- Alternator: 24 amps / 23 amps
- Chassis Bat: 20.5 amps/20 amps
- House bat: 3.5 amps / 3 amps

Engine speed caused charge amps to go up only about am amp or less.

Voltage: 14.2v

I don't recall what the alternator voltage drops to after driving for a while. I seem to recall the Scangauge in the high 13v range. I will check that next time I drive it.

I forgot to ask, would the two 6-volt house batteries be getting overcharged by the alternator if it was supplying a charge at about 13.7 volts over several hours of driving? If so, then I should install a disconnect switch for the isolator.

 

[markopolo-ClassB]

I wouldn't be too concerned about 13.7V over several hours of driving.

Any chance of you testing the Low setting B4 switch and recording the amp flow at 14.4V? It would be nice to know if it affects the transition from absorption to float. It might end up being a zero cost way to make sure the batteries periodically get a full charge. If it drops from 14.4V at 10A like your other test then you could quit the experiment. If it holds 14.4V for longer then it would be worth continuing the test to see at what amp flow the change to 13.5V happens.

 

[booster]

I forgot to ask, would the two 6-volt house batteries be getting overcharged by the alternator if it was supplying a charge at about 13.7 volts over several hours of driving? If so, then I should install a disconnect switch for the isolator.

13.7v is not ideal but is below the gassing point in most wet cells so not all that bad and will top off batteries faster than a 13.2v float. I think it might be best to watch what the alternator does over time, as our 07 Chevy would almost never get below 14.0v, mostly hovering in the 14.3-14.6v range. When I mentioned this at the time, it appeared to be quite common in the Chevies except in ones that had replacement alternators which most seemed to run in the 13.8v range. You have an isolator, so you may also be that high but losing .7v in the isolator, which is normal. If you switched to a separator, you would then be too high like we were. The downside of the isolator dropping voltages is that the batteries will not get completely charged at the desired voltage of 14.4v and the charging will be slower.



A manual over ride disconnect separator gives a nice system as long as you can see the amps to the batteries or SOC. You get full charge voltage to get right to full and then you shut the charging off. It does mean you have to have your battery monitor where you can see it while driving or have someone check it periodically.

 

[peteco]

You have an isolator, so you may also be that high but losing .7v in the isolator, which is normal. If you switched to a separator, you would then be too high like we were. The downside of the isolator dropping voltages is that the batteries will not get completely charged at the desired voltage of 14.4v and the charging will be slower.

Sorry I mis-spoke here. I have a separator, in fact it is the Blue Sea 7610 I got from you a while ago. It has been working great. Thanks.

I am taking a trip tomorrow and will check the alternator voltage. If the alternator voltages are high I will put in a switch to the separator to disconnect the house batteries from the alternator.

 

[booster]

Sorry I mis-spoke here. I have a separator, in fact it is the Blue Sea 7610 I got from you a while ago. It has been working great. Thanks.

I am taking a trip tomorrow and will check the alternator voltage. If the alternator voltages are high I will put in a switch to the separator to disconnect the house batteries from the alternator.

Sounds like a good plan. The separator would certainly help explain how you get full.

 

[markopolo-ClassB]

It's possible that the Duracell SLIGC115 is basically a Deka GC15. source: https://forum.solar-electric.com/discussion/339311/duracell-branded-6v-info

Charging a GC15 is detailed here: http://www.eastpennmanufacturing.co...Renewable-Energy-Charging-Parameters-1913.pdf

In a 12V setup from the guide linked above:
Absorption: 14.40V – 14.70V
Float: 13.80V – 14.10V

"Charge until change in current < 0.10A per Hr / Max Time: 12Hr"

It would appear that at a minimum you'd have to keep them at 14.4V until acceptance drops to 2A or less. It doesn't look like the Tripp Lite or the alternator can meet the recommendation.

There's no time limit on float so driving at up to 14.1V shouldn't be a problem (temperature compensated of course).

 

[booster]

It's possible that the Duracell SLIGC115 is basically a Deka GC15. source: https://forum.solar-electric.com/discussion/339311/duracell-branded-6v-info

Charging a GC15 is detailed here: http://www.eastpennmanufacturing.co...Renewable-Energy-Charging-Parameters-1913.pdf

In a 12V setup from the guide linked above:
Absorption: 14.40V – 14.70V
Float: 13.80V – 14.10V

"Charge until change in current < 0.10A per Hr / Max Time: 12Hr"

It would appear that at a minimum you'd have to keep them at 14.4V until acceptance drops to 2A or less. It doesn't look like the Tripp Lite or the alternator can meet the recommendation.

There's no time limit on float so driving at up to 14.1V shouldn't be a problem (temperature compensated of course).

This looks like it is one of the new charge complete specs in rate of change of charging amps rather than a fixed amp reading? Change of less than .1 amp per hour. Really tough to do, I think, and I don't think any monitors do it either. I might do it once to see what the amps are at that point and then use that amp amount for cutoff.


We found that anything above about 13.9v would gas our Trojans too much for my liking. The 12v batteries were worse than the GC2 six volt ones by quite a bit. It may have to do with temp as no correction and hot compartment or the ripple on the alternator voltage. You need a remote regulator to get temp comp off the alternator.

 

[booster]

Funny thought concerning a lucky match of use and charging with the Tripplite and alternator.


When we had that, I would find if 50% down the Tripplite would get the batteries to about 85-90% consistently based on specific gravity back then no monitor then, at about 14.4v. If petco gets the same and was at 13.6v off the alternator, or even a bit more up to 13.9v maybe, and drove after coming off a Tripplite charge, he would basically be doing a Charge Wizard charge profile.

Personally, I think I would chose as high as possible without gassing for the alternator to get done as quick as possible as the manufacturers aren't really keen on low voltage finish charging and like to go to finish at 14.4+v and then to low float. The Charge Wizard shows 36 hours to complete the charge.


All in all, I think getting the 14.3+ on the alternator like he probably has and using a cutoff based on amps will be the best, though.

 

[peteco]

It's possible that the Duracell SLIGC115 is basically a Deka GC15. source: https://forum.solar-electric.com/discussion/339311/duracell-branded-6v-info

Charging a GC15 is detailed here: http://www.eastpennmanufacturing.co...Renewable-Energy-Charging-Parameters-1913.pdf

In a 12V setup from the guide linked above:
Absorption: 14.40V – 14.70V
Float: 13.80V – 14.10V

"Charge until change in current < 0.10A per Hr / Max Time: 12Hr"

It would appear that at a minimum you'd have to keep them at 14.4V until acceptance drops to 2A or less. It doesn't look like the Tripp Lite or the alternator can meet the recommendation.

There's no time limit on float so driving at up to 14.1V shouldn't be a problem (temperature compensated of course).

Well, I put the wrong info in this thread for the second time. The batteries I got are the Duracell SLIGC125 (not the SLIGC115). I attached a picture of the spec plate on the battery. These are the Deka GC25 I believe as the specs match.

 

[booster]

Here is a cut and paste from another forum tha looks to be from a Deka manual that I haven.t found.


"The Sam's East Penn made Duracell GC2 is a Deka GC-10 with a Duracell Sticker. The Sam's EGC2 is a Deka GC-15 with a Duracell Sticker.

The recommendations from East Penn, for that battery, in a cycling / off-grid application are. (Note: floats are higher in off-grid than typical golf cart use).

At 12V:

Max Charge Current = 30% or less of Ah capacity (20 hour)

Absorption Voltage = 14.4V - 14.7V
Absorption End Point = Current change over 1 hour period of less than 0.1A
Max Absorption Time = 12 Hours

Float Voltage = 13.8V - 14.1V
Float End Time = No Limit

Equalization = 15.0V to 15.3V
Equalization End Point = Current change over 1 hour period of less than 0.1A
Max Equalization Time = 12 Hours

Temp Compensation = -.018V for every degree °C rise above 25C

Note:

For dock charging you may want to compensate float down to 13.4V to 13.6V the guidance above is for off-grid or deep cycling applications where the batteries are cycled daily.

Stick to the 14.7V end of the absorption range and the batteries will do much better if they are cycled while cruising."


If specs correct, I agree with the comments also. Daily cycling would explain the otherwise too high, IMO, float voltage of up to 14.1v. Trojan has similar different specs for daily cycling with 14.7 absorption and higher float than for non daily use.

 

[markopolo-ClassB]

The 14.1V float does seem extraordinarily high.

Several Deka pdf's mention it re: flooded monoblock batteries:
1. https://www.mkbattery.com/application/files/5315/3333/2574/Deka_Solar_Flooded_Monobloc_Brochure.pdf
2. http://www.eastpennmanufacturing.com/wp-content/uploads/Flooded-Monobloc-Flyer-0919B.pdf
3. https://www.mkbattery.com/application/files/7015/3333/2576/Renewable_Energy_Charging_Parameters.pdf

Then here's one - https://www.mkbattery.com/applicati...eka_Solar_Monoblock_Flooded_I__O_Brochure.pdf - for flooded monoblock that recommends much lower settings:

Absorption Charge:13.98V to 14.28V
Float Charge:13.44V to 13.56V
Equalize:14.64V to 14.82V

 

[booster]

The 14.1V float does seem extraordinarily high.

Several Deka pdf's mention it re: flooded monoblock batteries:
1. https://www.mkbattery.com/application/files/5315/3333/2574/Deka_Solar_Flooded_Monobloc_Brochure.pdf
2. http://www.eastpennmanufacturing.com/wp-content/uploads/Flooded-Monobloc-Flyer-0919B.pdf
3. https://www.mkbattery.com/application/files/7015/3333/2576/Renewable_Energy_Charging_Parameters.pdf

Then here's one - https://www.mkbattery.com/applicati...eka_Solar_Monoblock_Flooded_I__O_Brochure.pdf - for flooded monoblock that recommends much lower settings:

I ran across some MK references also. IIRC they had reduced electrolyte? concentration or some other oddity for special purpose use, and thus had the different charging. I think the manufacturers are still working on balancing complete charging and sulfation reversal against chronic undercharge capacity loss. For their "daily" charge on golf carts Trojan now has gone the step further past the 14.7v absorption to adding a mini equalize at the end of every charge. It has to be tough to have them way down every day and only have maybe 10 hours to get them all charged as well as possible. In the factories, we had the same issues with fork lift batteries, that often got charged 3 times a day by very, very aggressive pulse chargers.

 

[peteco]

Just got back from 5 days on the road. The Scangage showed alternator voltage of 13.5 - 13.7v on others. So that shouldn't lead to an overcharge situation I would think.

 

[markopolo-ClassB]

For new batteries, that seems fine to me as a float voltage while driving.

The previous 9 year old batteries might not have like it. If we think of a new battery as being a 12.8V battery (at rest) and an old battery as maybe being a 12.6V battery (at rest) then it makes sense that lost capacity would affect the charge side of things also.

I think years of undercharging leads to battery capacity loss and at some point, the usual/typical charging voltages become overcharging voltages.

I'm not certain that your setup can fully charge a battery. By full, I mean full as in 1 amp or so going in at 14.4V before switching to float.

 

[booster]

Yep, no real chance of major overcharging while driving, but is too high to be considered float as such and will use water to some extent.


Unfortunately, I would also think there is almost no chance that the batteries would get fully charged at that voltage, especially to the low amp spec Marko gave, so full charging would have to come from somewhere else.


A big question for me is what the old batteries were seeing for actual SOC and capacity. Most of the information that we have gotten from the battery makers would indicate that charging, even for long periods, at the lower voltages would shorten battery life due to capacity walk down. What is not clear to me is what the mechanism is, as I have seen that even when taken to low amps, float charge will continue reducing amps over the next approx 36+ hours. Is it that the low voltages don't have enough potential to convert some of the sulphate? Is it because just the extra time the areas of the battery that are in a discharged state is allowing the sulphate to get harder to remove? Anode or cathode erosions?



I think Progressive Dynamics is the only one that intentionally reduces the voltage to finish the charging with their profile, and they have done it that way for a long time.


The longevity of peteco's old batteries would have to indicate that whatever combination he was doing did not severely hurt the batteries. If there was walkdown, it had to be very slow in accumulating I would think.


Hopefully, peteco will put on a monitor and be able to see the results of how he is charging and using to give some clues, as it sure would be nice to know what made them last so long using the same equipment that others have while getting very short life from their batteries.