Leon 12

Your right there, a glorified voltmeter... Performed charge and after hitting 100% on Smartgauge, it took four hours to reach tail current of 4.75 amps,then a further 2 hours equalization charge and finally all specific gravities read 12.85...... 19.2 ah taken out over night....tv etc. Smartgauge 87% .... the voltage read 12.63 on the Bmv and 12.65 on the Smartgauge. The Smartgauge dropped 3% in 0.4 ah..Come on that's unreal.

As a newbie any information is good from an understanding point of view and to determine how things work. Not that you take all info as gospel but give you insight into looking after equipment. All of us were at some point in the same boat excuse the pun. Since joining this forum I have changed the way I charge my batteries,looked at my maintainence schedule and hopefully leads to a good lifespan of an expensive purchase.

The surest way to ruin batteries within a year or two is to keep them at a low state of charge (SOC) for weeks at a time. Active battery material will crystallize, covering the plates, which will become permanently inert. We call this “sulfation.” Ideally, batteries should receive a 100 percent full charge about once a week for good longevity, and more frequently is better. If this takes a full day of backup charging with a generator, do it! Use your monitoring system to know when full SOC is reached. If you don’t have an amp-hour meter, watch for the voltage to reach maximum and the charge current to drop to a low level. This means the batteries are unable to accept much more energy, and are accepting only a “finish” charge. In winter, some people run their backup generator for an hour a day—just enough to prevent the system from shutting down. Bad idea! It may be better to run it for ten hours, once a week, or whatever it takes to fully charge the batteries, instead of partially charging them more frequently. Finish-charging a battery bank with an engine generator is an inefficient use of fuel, and results in extremely long generator run times. As a result, generators are typically shut down once the absorption charging stage is finished. But at this point in the charging process, the battery bank will only be at about 85 percent SOC. Since regular, full battery charging is important for battery longevity, make sure that your RE sources are topping off the battery bank after the generator has done the bulk of the charging. Relying on your PV system to provide the finish charge may be difficult during winter months. Another option is to set the inverter–charger to equalizing mode (see below) during generator charging about once a month to ensure that the battery bank is getting fully recharged. The extreme of undercharging is called “overdischarging.” Voltage should never, and I mean never, be drawn below about 11 V (for a 12 V system), or 22 V (24 V system), etc. System controls and inverters usually include a “low voltage disconnect” (LVD) function. If you have DC loads connected directly to the batteries without LVD, you are asking for trouble. It’s better to lose power than to squeeze out another watt-hour and damage your batteries. Metering is vital here, because if you wait for the inverter to shut down or the lights to go dim, it’s already too late—batteries will likely have lost a portion of their capacity and life expectancy. Finally, flooded batteries need to be equalized at least four times a year. Exactly how often depends on several factors, including the size of the battery bank in relation to your charging sources and the average depth of discharge during cycling. During normal battery discharging/charging, the individual cells of each battery will stray from a common and consistent cell voltage. Equalization can be thought of as a controlled overcharge of the battery bank that serves to both equalize cell voltage, and provide an aggressive and necessary mixing of the battery electrolyte. Equalization charging can be done with your PV system if your array is large enough, or with an engine generator or the grid. Most PV charge controllers and inverter­­­­–­chargers have battery equalization functions.

The ideal battery bank also is the simplest, consisting of a single series string of cells that are sized for the job. This design minimizes maintenance and the possibility of random manufacturing defects. Suppose you require a 700‑amp-hour (AH) bank. You can approximate that with a single string of 700 AH industrial-size batteries, or two parallel strings of 350 AH (L-16 style) batteries, or three strings of 220 AH (golf cart) batteries. The diagram below shows these three variations. A common blunder is to buy the smaller batteries because that approach is less expensive up front. The problem is that when current splits between parallel strings, it’s never exactly equal. Often, a slightly weak cell or terminal corrosion will cause a whole battery string to receive less charge. It will degrade and fail long before other parallel strings. And because partial replacement aggravates inequalities, the only practical solution is to replace the entire battery bank. One way to reduce or avoid parallel battery strings is to use the highest DC voltage standard that is practical. The same batteries that would form two strings at 24 V can be wired all in one string for a 48 V system (now a common standard). The quantity of energy storage is the same, but the layout is simpler and the current at critical junctures is cut in half. If you must have multiple battery strings, avoid stacking cable lugs at the battery terminals to make parallel connections. Instead, bring wires separately from each string to two bus bars outside the battery box. This reduces corrosion potential and helps create electrical symmetry.

How Can You Squeeze More Years (Cycles) Out of Your Battery Bank? This starts with the design. Minimize the number of strings of batteries by using higher Ah 6V or 2V batteries. Having fewer strings can help distribute the charge equally across the battery bank. Make sure your battery connections are at opposite corners of the battery bank. This will also help equalize the charge and discharge distribution across the battery bank. The last tip involves rotating your batteries within the series strings can help with more evenly distributed charges between cells. Use this opportunity once a year for your Saturday exercise routine and not only will you be in better shape, but you will save some money by extending the life of your battery bank. (Ok, we threw in the exercise part in to see if you were paying attention.)

Multiple parallel battery strings are only good up to a certain point. 1 string is ideal. 2 strings are okay. 3 strings are tolerable. More than 3 strings is just BEGGING for trouble! Tiny resistance differences between strings are unavoidable, and electrons being the supremely lazy things they are will always try to take the route of least resistance. With 2 or 3 strings battery string imbalances can usually be kept within control. But with more than 3 strings it’s inevitable that some strings will end up doing all the work, and some will do next to nothing. Neither condition is good for battery life expectancy.

That is what I'm looking at also but will stick with the 60 amp as I can't push to get two. I also have a 675ah battery bank. Trojan recommends 10 to 13% of bank capacity.

Update on battery capacity......... Performed charge today. The smartgauge read C69 and had consumed 79 ah according to the BMV that was a 20 ah change from the previous drop to C69 on the smartgauge. The voltage was still 12.45..... So it held ok. I charged withe normal setting first for 30 minutes then changed to the equalization setting for a further two and a half hours. So what that means in terms of capacity I have no idea. If it takes 3 hours to charge from 31% DOD then what will 50% take?? The sterling ultra charge is the way to go 60 amp which has a user setting so I can input the correct trojan settings also it has a temperature connection so it will compensate high or low temps.

On the Trojan website there is a note. maximum parallel strings 3 just where it shows you wiring config.

Someone mentioned using the equalization charge 15.5 volts. Does it still build up to 15.5 volts or is it instant.? Would it be wise just to use the charge setting on the sterling?

8 t 105, I have six and I think from what Trojan says anything over three strings its not as good. Series Parallel wiring. I might be wrong.

smartgauge hit a steady 82% but had used 38 ah which in comparison is 15 ah more than the same stage before charging 2 days ago. looks promising and given time I will see a marked improvement.

I find the bmv to be more accurate voltage wise, the SG just goes 12.55,12.60,1255,1260. Whilst the BMV gives a nice 12.67 or whatever it is. The tracer is always higher rounding up to the next ie...12.60. I understand that more ah have to be replaced than used so now when it goes into float early I just turn the charger off and on again and it continues at absorbtion stage. After doing the charge and equalization it is already showing signs of improvement. I will let the smartgauge run down to 69% and see how many amp hours were used....last time it was 58.5. Voltage held true and good which im chuffed at too.

hi Rowland, removed all connections and cleaned followed by making sure all connections were good. When it comes to any equipment regardless of the purpose you shouldn't have to second guess it. if I buy a kettle and it don't boil at 100c then its not doing its job. The smartgauage website needs to be updated to these shortcomings. The BMV may fall sWort over time but at least it can give you more relevant info. I understand that over time it falls out but the smartgauge falls out before which to me is worse. what I need is info of going in. when I drop to 12.26 volts I recharge. people at Trojan said I could go to 12.00 volts but I don't want to run genny for 5 hours plus.....

Many thanks. Any help is so thankful. I will pop some pictures of what I have done to the boat on here.

On equalization mode it kept a steady 15.5 volts and 10 amps, would it still tail off as in normal charge mode.

Would that be ok to do so? Made me gulp Hi nick, because of the nature of the Trojans with increasing capacity until its achieved I have no way of inputing the ah in the settings of the victron, I am gestimating the capacity. Which is pretty futile.

I have altered the tracer to compensate for temp and what trojan states but until I can find a suitable charger, one that I can input charge voltages I am kinda stuck. The sterling inverter charger on lead acid setting is 14.813.3 and 15.5 in equalization mode. Are there any other brands that let you use a user setting?

1.277 for trojan batteries at 80 degrees A clever voltmeter..........lol

Surely temp affects gravity....so at 70 degrees it would be 12.75 however at lower temps specific gravity is lower but still fully charged. All specs are at lab conditions not in the real world my hydrometer said deduct 12 points for the temp it's at so that would indicate 12.63 fully charged. Am I wrong with this assumption. Trojan specs are at 80 degrees f. Deducting 0.004 for every 10 degree drop so today it was 10 degrees so at test it would mean 0.028 deduction in reading and that would be 100%.

As others have said above the smartgauge is flawed. If you go by what it says during charge and in reality that is false ie ..out but then it rectifies during discharge then initially it's wrong whatever the final outcome is. No one wants to second guess something that tells them 100%. I am in no way putting smartgauge down but in my opinion it is a flawed piece of kit.

Hello, my batteries are wired in a stereotypical series/parallel configuration with 35mm sq interconnect cables. My history with these batteries is as follows. After purchase they were stored for 2 months. After installation they were connected to shoreline via the inverter charger on float. Also connected via two 100 watt solar panels connected to a tracer 30 amp. My belief is that trojan batteries are at 70% capacity when new and over the next how many cycles they steadily increase to 100% capacity......since moving to my mooring I have only cycled maybe 20 or so times. So they wouldn't even have achieved full capacity. Now the smartgauge must use resistance of some sort to determine capacity and voltage. But how can it not see that Trojans no matter what the voltage is at full return that in capacity. A trojan will develop capacity from new in its own time ie..125 cycles. The Trojans were 100 % and dropped to 79% very quickly...only 23 ah. Then from 79% to 69% it was 60 ah so in that 10% of drop there was a 37 ah drop. Maybe it's my weird logic but if say after 20 cycles I had built a further 9% of capacity that would then tie in with the 79% capacity what the smartgauge was saying. You could throw any amount of charging and equalization but until full capacity is achieved via cycles Trojans will only ever show the capacity they are at at that given point. I performed a 3 hour charge to which the tail ended at 7.34 amps then a 3 hour equalization charge. 8.15 am 42 amps going in at 13.7 volts 8.25 am 48 amps going in at 14.02 v 8.34 am 46 amps going in at 14.4 v 9.15 am 26 amps going in at 14.5 v 9.32 am 19 amps going in at 14.6 v 9.56 am 13.4 going in 14.61 volts 10.15 am 11.4 amps going in at 14.67 v 10.19 am 10.8 amps going in at 14.65 v 10.45 am 8.4 amps going in at 14.70 11.30 am 7.34 amps going in at 14.70 volts Both smartgauge and victron at 100% Equalization performed at 15.5 volts at 10.5 amps Gravity readings at 12.75-80 across batteries. So let me know what you think.

As a novice boater, the smartgauge is an accurate piece of equipment to a degree but its flaws can be detrimental somewhat when you act regarding what it says. Unless you join a forum and discover the true workings you could be always undercharging. From what I have gathered in these last few days there is more to charging than looking at 100% on a readout. My first point of call is a full charge followed by Equalisation of four hours at 15.5 volts........Sterling inverter charger. Then I will replace the inverter charger with the pro ultra 60 amp to which I can input my Trojan settings,it has temp adjustment and an equalisation setting......Also replace the cross leads with 70mmSQ cable to match the rest and hopefully I will have amore acceptable amp hours to work with............ maybe I will use a candle instead to read with.

I have the Honda EU20i so the 60 amp should be ok. When I got to the boat last night the smartgauge read 97% and after 23 ah useage over the night ....tv pumps etc, it read 84% So that equates to only 100ah roughly in a bank of 675ah available from the readings. The voltage held good 12.85 when I got in last night (5.30 pm) to 12.57 this morning at 4 am (when I left for work). My Batteries are series parralled with three strings connecting the batteries 70mmSq cable from inverter charger also 70mm cable connecting the positives/negs on the strings and 35mm sq cable connecting the cross positive to negative. The shunt is in place and the smartgauge is connected on the furthest negative. So wiring is in place correctly. Would sulphation be so aggressive and leave only that amount of amp hours or could it be a wiring or a dodgy smartgauge............ any suggestions please.

Hello, which pro charge for 675 ah bank...the pro charge 50 or 60 any views.