How "fast" you can reliably charge your battery.

[CSY Man]

Hmm, oaky Mr. Bill.


Thanks for the input.

Yes, I am considering the gizzmo, that is why I keep asking Mr. Rick why I really need it?

He sure is building a good case for and so are ya...

So, uh yup, I am checking my savings account to see if there is room for a LINK 10, and also checking my electrical panel, any room left after all them analog gauges and all them radios?.

Thanks to all, good feed-back and I am almost convinced..

[Talbot]

I like your philosophy. I also have solar panel, 750w emergency gennie (normally used for winter maintenance), and supposedly ability to hand start engine by decompressing and using a rope, but as I am not charles atlas, I have never tried it!

[CSY Man]

Rope start...?

Hmm, that is something I am not so sure would work on my engine (Perkins 4-108)

Don't have a decompression lever, even if I had one..well, I could take Rambo along for a crusie and ask him to crank the beast.

Bill:

Ya said:

How many amp. hours taken out versus how many put back in.

Well, I have a failry good idea how many amps I take out:
Have a digital hour-meter on the fridge and check the hours on a daily basis:

6 hours running X 6 amps = 36 out...Then to put the same amps back in, multiply by 120 = 43.

Also know how much the anchor light consumes, etc.

My analog amp meter tells how put the alternator is putting out.

Say if it indicates 60 amp, slowly dropping to 0 over a one hour period, that should be about 30 amps back in the batteries.

(Rough estimate, I know, but I am a "loose" kind of guy anyway. )

So, yeah, a Link 10 or equivelant would certainly give me more precision in managing them batteries, but the end result may be the same..

Going to keep an eye on E-Bay however...West Marine says $229.00 plus taxes for the unit, probably half that on E-Bay..Then there won't be much excuse for not putting one in.

[Alan Wheeler]

Hi Rick.
Two questions if I may.
No.1- Battery chemical additives to rejuvinate older batteries. Are they snake oil? or worth the cost??

No2.- What manufacturers of step chargers out there, do you recomend, that do the job correctly. There are so many and I know not all are created equall. But it is sure hard to see the brilliance within the BS on advertising literature.

[CSY Man]

Good question Mr. Alan, I have been wondering about that myself.

Here is a link:

http://www.batteryequaliser.com/index.html

Another wonder gizzmo to prolong life and even restore a battery from bad to good:


http://www.europulse.com/eng/index.shtml

Too good to be true, OR truly good stuff?

[Rick]

In "the industry" it is estimated that about 85% of lead-acid batteries (flooded-construction, AGM, GEL, VRLA, etc.) are killed by permanant sulphation (technically known as sulphatation, an irreversible form of lead sulphate) due to undercharging (which includes standing for long periods short of a full charge).

Most cruisers are short of a full charge regarding proper care and knowledge of their batteries and, I suspect, that the number exceeds 85% killing of the batteries in terms of possible life under repetitive cycling.

It IS known, for example, that if you fail to reach a proper minimum acceptance voltage for a sufficiently long period of time the battery continually degrades and looses capacity on repetitive cycles. Of course there are those who kill their batteries by excessive long-term gassing as well yet those numbers are small by comparison to the undercharged case. Therefore, yes, you are correct as long as you continually monitor your electrolyte level.

For those who are using non flooded-cell constructed batteries where you are not able to replenish lost water I will alter my opinion to say that a monitor such as the Link 10 or Link 1000 is absolutely necessary for the longevity of the batteries (assuming the availability of proper charging sources and regulators as well).

I am plannning to start another string regarding charge acceptance and how to use that as an indication of recovered charge yet such a subject is fraught with pitfalls and I must think how to present it without sending my halyard to the masthead.

Later,
Rick

[Rick]

First battery additives: Along with the myth of removing the electrolyte and adding new the various battery additives can seem to revitalize a battery's output FOR A SHORT TIME and then you are left with what you had before on the way to being junk. One technical reason for understanding that these desperation moves cannot work ultimately is that in the forming of the positive and negative plates during the manufactruing process, specially formulated pastes are used which, over a time period and charge regimen, form the interface to the electrolyte. Once this interface is destroyed, or damaged it cannot be "redone". This formation is not the lead sulphate or lead ozide formation which is normally reversible under the influence of the paste chemistry formation.

"Fooling" with the electrolyte may temporarily help to remove some permanent sulphation yet, in doing so, usually damages the rest of the normally uniform plate makeup. Obviously one cannot mess with the electrolyte of the non-flooded batteries which, I predict, will largely take over the large percentage of lead-acid applications when used with proper charging and monitoring gear. The newer generation will have a monitor built in to the battery and merely interface to an energy management system.

I have looked at some of the pulse chargers and, in at least one case, discovered no apparent or measureable improvement in the sulphation of the battery. In the case of permanent sulphation (sulphatation) I do not believe that a pulsing charger, even the ones with positive and negative pulses, can remove the crystaline lattice structure. I DO believe, however, that the manufacture of those units confuses heavy sulphation which IS reversable with permanent sulphatation.

Along with my skepticism (bordering on the edge cynical) as to the veracity of such wonderful claims of pulse chargers I have a theory that any such claimed recovery of sulphation as to compared with a charger set up to closely approach Amp-hour charging will result in the same or less Amp-hour recovery. You do not see such comparisons. I am open minded as to the possiblilty that the inclusion of some type of pulsing in conjunction with a Amp-hour type charging system may recover some small percentage of lost capacity normally attributed to premature aging if such a phenomenon can be carefully separated in the overal picture of potential capacity.

BTW, please don't confuse Amps, Amp-hours, and kilo-Watt-hours. Some people use all three interchangeably without noting the differences. Historically battery users used Amp-hours as a capacity measurement because battery monitors capable of measuring kilo-Watt-hours (true energy) did not exist. Modern proper battery monitors actually monitor Watt-hours internally displaying Amp-hours as a default for the traditionalists. When you say that you used so many "Amps" you are missing something capable of differentiating instantaneous current (Amps) from current-time accumulation (Amp-hours) and expression of true energy (current multiplied by time multiplied by voltage).

Because voltage is missing from an Amp-hour measurement a comparison between different battery types may be misleading. For example, a flooded-cell battery often has a charged voltage of 12.7 Volts and a particular AGM may have a charged voltage of 13 Volts. Both may "measure out" at the same Amp-hour value yet when multiplied by a higher voltage over the discharge period the AGM may exhibit a higher value of Watt-hours than the flooded battery. Therefore, a bilge pump will pump a shorter period of time for the same amount of water discharged when using that AGM than when using the flooded-cell battery when both tests are begun from a full state.

Don't misinterpret this, I am not saying that all GEL or AGM batteries are bettery than flooded-cell constructed batteries. I tested one AGM which was absolutely dismal in both measured Amp-hour and Watt-hour delivery. Similarly the debate between AGM and Gel batteries is meaningless without declaring a specific battery brand and model to compare. Some are good, some are excellent and others lousey.

Regards,
Rick Young

[Rick]

Sorry for the omission of Law in "Amp-hour charging".

[Rick]

The best 3-step alternator regulators are ones which allow you to set the absorption, float, and time-to-float independently. I am, naturally, prejudiced towards my own designs, like the Alpha, the Link 1000 (when used with an inverter/charger), and others. These products are now "long of tooth" and new ideas should have driven the market towards better replacements.

Some units do not ostensibly allow you to directly set the voltages and one must decipher the instructions so as to fool the control unit by setting other battery types and temperatures to get the desired voltages, if possible...look at the manuals to decide if you can do this. If, for example, you want a higher acceptance voltage you might be able to "set" a temperature of 50 deg. F to get a higher value that using a temperature sensor or a 70 deg F setting.

The Balmar regulators are, in general, good even if difficult to set up or change. I do not recommend using their powder-coated alternators because the inherent cooling ability of coarse casted aluminum is superior... just like the motorcycle cooling fins on the engine cylinders. There are some who have been ignorant enough to paint their cylinders with black paint (or polish them) thereby filling in the effective surface area of the aluminum and they suffered heating problems in slow traffic and hot days. Lestek or Hehr (and others) make the same output units with better cooling capability (and probably less money).

I even use an Alpha regulator (named differently by Heart Interface and Xantrex if they are still shipping them) to control the voltage on my starting battery (using the stock alternator altered for external field control) with the float and accept voltages set to the same value for better voltage control than with an internal alternator regulator. With a good installation a voltage setting can be controlled within +/- 20 milli-Volts.

Automatic battery voltage control should be bettery than 50 milli-Volts and, therefore, any measurement system (control or monitor) needs to have around a 20 mV resolution or better. Many of the inverter/chargers do not have this, especially those using 8 Bit A/D converters and, as a result, the charge voltage varies +/- 100 mV or more causing a widely varying battery charge current.

3-step chargers: There are now a lot of these on the market and there are many good ones. I prefer those used in conjunction with a battery monitor thereby giving better automatic control for your specific battery. My favorite combination is the Link 1000 used with an external battery temperature sensor and the old "black" Heart Interface Freedom inverter/charger. The larger units like the 2kW and 2500W units have REAL internal transfer switches better rated to transfer the full 30 Amps of shore power without concern about relay contact overheating. The newer products in that line have what I call "wimpy" relays mounted on the PCB. The later model Trace units are good. Check the Outback Engineering inverter/chargers are good because virtually the entire Trace Engineering team has reformed over there to make more good products.

We are seeing good high frequency "switcher" products on the market which have great weight and size advantages over the old "line-frequency" inverter/chargers. In addition, some of them convert energy from the entire sine-wave of a generator waveform which does not require a derating of the generator power when attempting to utilizing all of the generator power for battery charging. Affordable line-frequency chargers extract their energy from only the peaks of a line source thereby distorting the waveform and causing a significant power factor degradation which limits the ideal amount of current available from a shore power breaker to maximize power use aboard, limited as it is already.

[Alan Wheeler]

Allo I can say is WOW!!!!!.
Rick, do you have any web address for Outback Engineering ????
I would like to check out what they have available.
Thanks heaps,

[GordMay]

OutBack Power Systems
19009 62nd Ave NE
Arlington, WA 98223
Tel: (360) 435-6030 ~ Fax: (360) 435-6019
http://www.outbackpower.com/

BTW:
Their basic (Cabin, RV, or Boat with solar) wiring diagram at http://www.outbackpower.com/pdfs_wir...IN-RV-BOAT.pdf
shows (4) 6-Volt Batteries (series-parallel), with the load connected to the positive & negative of the same series bank. Should'nt the load be connected to the positive of one series bank and the negative to the other series bank?

Thanks for all the good info' ~ you're giving us lots to digest ...

[Rick]

Gord's absolutely correct! The idea when cabling to a battery bank is to "look" at the load leads from each individual battery in the bank and "see" the same length of cable (total positive and negative lengths) so that the parasitic resistance of the cables are the SAME for each battery. This is most easily done by using symmetry in penciling out the leads before running the cables.

Once I was sent to a truck manufacturer using Trace power inverters and a series-parallel combination of batteries. The problem was that the inverter was shutting down under loads around 100 to 120A dc and some of the batteries would gas and others not when charging. With the inverter running I could measure with my DVM a significant difference in each battery terminal voltage. By merely rearranging the cabling so that each battery ran its load through the same effective length of cable the problem was solved and everything operated normally.

Even though the cable size may be 2/0 or 4/0 don't think that a significant percentage of current change into a particular battery will not occur over time as its internal resistance fails to "track" similar values in the other batteries carrying more or less of the load percentage. (I'm not saying this very well...just trying to make the point that the non-linear internal resistance of a battery can exacerbate the current sharing problem more than one might think).

Rick

[Donalex]

Have I the honour of communicating with the designer of my Link 1000?
If so thanks for a great piece of kit.
Here is my question.
The unit consumes about 45 mA constantly when in sleep mode.
The minimum resolution of the ammeter is 100 mA.
This means it shows a constant 0.1A discharge 24/7. Over a month it clocks up 17 Ah battery discharge when, in fact only half this is about right. Over 3 months winter non-use it can falsely show considerable loss of Ah which is not actually occurring. I normally reset the Ah cumulative reading but never know if I am deceiving myself.
Would I be better off connecting the 0V return from the meter to the battery side of the 500 amp shunt so that the unit did not read its own power consumption - or is there a better work around?
Regards,
Don A.

[FlyingCloud1937]

I wanted to bump this topic back up due to the many topics recently on battery charge rates.

This is a great topic, and Rick is a wealth of real battery knowledge.

Lloyd

Originally Posted by Rick

This discussion applies to deeply discharged house batteries and not start-only start batteries. A deeply discharged battery is one which is "missing" 10%, or more, of its potential capacity (note that I did not say "rated" because an aged battery will not exhibit a fully charged potential capacity equal to its rated one).

The answer: A charging current equal to the value of the number of Amp-hours missing from the battery will not excessively gas or heat the battery. This is the so-called "Amp-hour Law" which was proposed many years ago in the literature. Now what's interesting about this concept is that a charge curve following this "law" forms what is called the curve of Epsilon, an ever decreasing curve of charge current. What is also interesting is that when using 3-step chargers having an appropriately set absorption voltage and a sufficiently large charge source the resulting curve will almost approximate the Amp-hour law. When precisely following this curve you can safely recharge an 100% discharged battery in 3 1/2 hours with many AGM and GEL cel batteries and closer to 4 hours for flooded batteries. All lead-acid batteries designed to deliver heavy discharge currents (like you need for cruising with a microwave oven, etc) will be capable of folloing this "law".

If you have, for example, a 400 A-hr bank which is discharged 50% then you can safely begin charging at 200A. Immediatly, of course, the current begins to drop to follow the curve. If you have a battery monitor and an adjustable voltage setting for your acceptance charge voltage you can observe the A-hr value missing from the battery and switch to observe the charge current setting the charge voltage until the current equals the missing A-hr value. Guess what? If you do this you might notice that for your system the voltage required to do this initially might be close to 14.7 to 15 Volts for ambient temperatures of about 70 degrees F. If you keep watching you might notice that with some AGM and some GEL batteries you can leave the voltage there and the battery charge acceptance prevents the charge current from greatly exceeding the Amp-hour law. Note that the Amp-hour law does not dictate that the curve should not be exceeded merely that if you want to GUARANTEE no excessive temperature rise or gassing you may follow it.

Obviously 14.7 Volts is higher than the "normal" setting of 14.4 V for 70 deg. F, yet not by much. You WILL notice, however, that a mere 100 milli-volt change can cause huge current changes, which is why a well regulated source is desirable. Why am I telling you this? Because when Ample-Power and Cruising Equipment (They influenced Heart Interface as well) began promulgating the concept of using 3-step charging they picked a first-approximation to this Amp-hour curve which would, in general, be relatively easy to implement yet safe for the batteries. The IMPORTANT result is that capacity lost to a dischargte cycle can be immediately recovered. Charging a deeply discharged battery at voltages always below the recommended acceptance voltages DO NOT result in capacity recovery on a repeated cycle basis and equalization cycles are required to do so. Using higher acceptance voltages resulting in a closer Amp-hour curve CAN recover lost capacity (unless permanent sulphatation has occured).