First Top Charge

Bubble-bubble-bubble

This will tell you where you are at, fast and easy. The time consumed in top charging vs bubbling or not is easy to manage. Use a watch or a clock. Top charging should be effortless, not a chore.

sjturbo wrote:
Thanks niner! That is what I was doing during the Top Charge, (turning it off to read the battery voltage). It just sounded like something else.

You need to let the battery sit for a while, like 24 hours, to get rid of the surface charge voltage, which will give you an artificially high voltage reading, usually right after recharging a battery to near full 100% capacity. So don't rely on that voltage meter sitting on top of your Mega Watt for what the current battery voltage is, if you just turned the Mega Watt off. As I said before, it is only a rough barometer reading, voltage. It bounces around quite a lot. Use that voltage meter on the Mega Watt only for setting the charge voltage on the Mega Watt, when the Mega Watt is disconnected from the batteries, and the switch to the Mega Watt is turned on. You may want 14.8 V at times, and you may want 15.0V or maybe even perhaps a bit more than that. Spreading slightly over 15.0V occaisionally on all the batteries you have, with their amperage capacity, would be nothing more than a stirring charge to mix things up, if you've been in storage, or are not using the batteries daily.

With some time, practice, and logging V while camping or living off the grid, the voltage reading on the Mega Watt might provide you with some insight, you'll notice what is to be expected, what is normal, and what is abnormal.

Thanks niner! That is what I was doing during the Top Charge, (turning it off to read the battery voltage). It just sounded like something else.

sjturbo wrote:
I just ordered the Freas, looking forward to being able to read through good glass. One of the many puzzles I have not been able to answer is when charging with the Mega Watt how do I need to wire in the volt/amp meter so it is reading what the battery charge is vs the Mega Watt output? I have the meter tied to the shunt on the negative output of the supply now. So how should I have it?
Thanks.

If you shut the Mega Watt off, but leave it attached to the batteries... it will continue to only give you a voltage reading, to the 1/10th of a volt, until you disconnect the Mega Watt cables from the battery terminals. Voltage readings will sag or drop based on amount of load applied currently to the battery, or if there is a surplus surface charge if no load is on the battery, the voltage could read higher. That voltage meter is only a barometer for the voltage of your battery and state of charge. The only thing absolute is what your specific gravity is, per battery. Forget what the voltage is for final determination for state of charge.

MEXICOWANDERER wrote:
The Mega is plenty big enough. I mused this for a bit and came up with an idea. Apply the Mega. 15.0 volts. This time disregard the amperage. Instead monitor the acid in all cells. When all cells are bubbling slightly note the time elapsed between start to finish. This can easily eat a couple of hours, so don't worry. Just ensure you are starting from a level of battery charge that is easily repeatable. That way you can top charge with a timer. I'm soooooo lazy I use an interval timer, but one with a battery backup (I further cheat and use a cheap 12 volt voltage regulator and timer and suck power off the 24 volt bank - not likely to run out of memory). A weatherproof timer is inexpensive and you will look for a lawn sprinkler TYPE timer, which is called an INTERVAL TIMER. While I'm doing important things like reading, snoring, or staring out across the sea the timer and charger is doing it's thing. Not important whether your timer is AC or DC, but it is important that it not lose it's mind (timing cycle) because of a power outage.

Let those batteries bubble a little. If one cell is reluctant, find out why. Usually it is a sign of sulfation. Do an equalization. Then try it again down the road. Bubbling the start of which is an incredibly underused tool in battery management. Use it to VERIFY your perception of state of charge.

APART: I would love to see - it would be my reward to see declarations here "Gee I followed this stuff, it was simple, and it apparently doubled the lifespan of my batteries". Then I will have accomplished my goal. Vamos A Ver.

The increase of sophistication of these threads puts a smile on my face - thanks guys, for the time being, that is reward enough :)

Oh come on Mex... I have two H-1 dated 1275's that were deemed in need of recycling by December 2013, thrashed hard for their 500 recharge cycles in golf carts here in So Cal, where they play golf all year round in shorts, every day of the week, every day of the year, rain permitting. They were two years old and pounded on daily when I got ahold of them.

Is squeezing another useful year out of both of them, still with no major signs of quitting, using your technique, considered reward? Let's see how far they go, they are working for me, not me working for them, so that is a win-win. If I get one more year out of them, is that considering their life being doubled by you? There's your sign, I am sure I can get another year out of them, so consider it a success, your advice has worked for me, so far. A good top charge adds so much more capacity to my batteries, the first week or so of camping, not much sag.

Now then... my reward will be you managing to score something simple like spare new batteries and portable chargers for you Galaxy S2 SGH-I777 AT&T smartphone I gifted you while you are down there in Old Mexico. You have your work cut out for you.

AFAIK, that 50a shunt is only good for monitoring the mega watt's amp output. If you're looking to monitor the battery bank, you may need to use a 500a shunt. They usually have 3/8" bolts, so you would just connect a short heavy cable from bank neg to one shunt post/bolt, and ALL other negs to the other shunt post. All other negs would include all loads, as well as the charger's neg cable. This way everything, in or out, will be monitored.

Page 7 of this manual shows how it's done with a Trimetric. Page 8 explains the wiring from shunt to meter:

http://www.bogartengineering.com/sites/default/files/docs/TM-2025Install%20Instructions9-12.pdf

Can you post a link to the meter and shunt you have now?

thanks

I just ordered the Freas, looking forward to being able to read through good glass. One of the many puzzles I have not been able to answer is when charging with the Mega Watt how do I need to wire in the volt/amp meter so it is reading what the battery charge is vs the Mega Watt output? I have the meter tied to the shunt on the negative output of the supply now. So how should I have it?
Thanks.

Jrnymn7,

That is because from the onset I knew the battery was the boss of the game. Diplomas, degrees, and an entire inventory of toys amounted to squat. The battery was and is king of it's own hill and you either play by it's rules or get the hell off the hill.

Out of all the phrases, all of the comments I ever made, my customers made my engineers made there is one that stands out "Why the hell doesn't...?" Electrochemical devices gain personalities. Some are good, some are bad, some are, well, to be frank...seemingly haunted. Trouble in paradise happens when a designer declares "This will make the battery do..." Boy have I got news for them "Let's do this and see what the battery does..." is the correct attitude. Use the number "10" to describe the number of different designs, then multiply by another 10 to gain an appreciation of the different ways a cell can age, then multiply that by ten to assume the number of ways a battery can be maintained and used. The sum is going to be predictable? On paper? Shirley you jest! Actually the number of permutations far outstrips the pitiful numbers written above.

However the owner who bothers to learn just a bit about the "personality" of his electrochemical experiment can indeed predict and calculate to a definite point what to expect. By controlling voltage and time, suddenly the unknown becomes not only wide open, but it becomes easy, furthering the knowledge by learning trends & tendencies of the battery, then makes battery management so easy, it's almost funny.

Jesus, tells me "You write every day three hours, then go visit the batteries ten minutes, some days not at all?" Truer words were never spoken. Just completed a solar still for mineral free water. Imagine a shallow bowl six feet in diameter. Lined with shiny side aluminum foil. Four inches up reposes 50' of three-eight's inch copper tubing painted flat black. Two window panes cover the coil. Suction is out of a 5 gallon black can. It yields about half a gallon a day, and the spiral needs to be blown down (drained). I use 60ppm "purified" water as feedstock. When I accumulate ten gallons it will be hauled to the gen shed and be set up shoulder high. There are 2 coils, one heating, one condensing.

in closing this little ditty may I remark that I follow each and thread, each comment, every observation, every chart. Time to go - the girls are here and I have only three days left before I have to head back to Baja California. What's on the menu? About 10 lbs of lobster, cold macaroni salad, salsa pico de gallo on tostadas, and cantaloupe agua fresca. At least I got to bring the kids one load of gifts! Thank god for Volaris 99 dollar flights!

sjturbo wrote:
Menna661, Tell me about your batt Bank. As you may have read it took me about 11hr to get my bank to 14.8v. I realize that #4ga ,may have something to do with it but 11hr seems like a long time even with that gauge. What is your starting voltage and how long does your Mega Watt stay at a high amperage? My voltage/amperage started out at 15v/33A. Amperage dropped to the 3-5A range quickly.
So tell me jrnymn7, Is your PS a Turnigy 1080Watt? How do you Top Charge?

I don't use mine for regular charging unless it's from higher SOC's where I don't care about high amps, I use my Iota converter (well....when it was working) or my Black & Decker portable for that. I also don't top charge much cause my float V is good. Mine is used primarily for floating and the occasional de-stratification charge (tall batteries...something you guys don't have to worry much about). For the de-strat charge, I start out with 14.8V and let it run for 15 mins. Typically starts out at 24A and tapers from there.

EDIT: I did do a short boondocker this past weekend. When got home batts were down about 14Ah. Started charge at 14.7V. Amps went up to 36.4 and hung out there for a few minutes then tapered to 29.

Mex,

What I have noticed is no-one comes on the forum complaining about good battery management techniques, like the ones you recommend, resulting in under performing batteries. Otoh, there is no shortage of threads regarding the use of converters resulting in under performance. That, to me, speaks volumes!