My battery soc

Re: My battery soc

I think you need to collate two things to see if they match, Volts per cell and the SG level. At 48 volts or 2v per cell and a SG level per cell it'd be around 60% soc.

http://support.rollsbattery.com/support/articles/430-corrective-equalization-

This a Industrial Battery chart with 1.280 electrolyte as you have. This one is easy to read ( 10% resolution ), again you can Google 100's of them.

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Re: My battery soc

There is your answer, listen to GB and do your thing. You and Coot seem to have a plan, if it doesn't work out then, I guess you'll have to try something else. I know what I'd be doing, but you don't need my $.02.

Re: My battery soc

I agree, I don't see that much of a problem. I believe with the HBX Mode activated, I can't see how you could ever drop to 45V if it was set correctly. With a Grid connection and some massaged settings it should take care of itself. That is what Grid-Zero is about, but you have to get the settings right. You can always lower them at the expense of the battery if you consider it expendable. A lot would probably correct it's self overtime with the proper absorbs and cycling.


I have watched Industrial Battery service techs, what I saw them do is take a piece on masking tape and mark the 6 lowest cells SG level and then hammer it at 62v on a 48v battery for as long as it takes. They would check the SG every 30 minutes on those cells and look for a rise, as long as they were getting a rise they would keep on going. Yes, you need to monitor the temperatures and keep them below 115f - 125f. Even the Rolls - Surrette white paper recommends 3 hours after no rise as a stopping point on the lowest cell. This battery has 25" ? tall cells and at least .250 thick plates and will take a lot before you could cause any damage. Part of the issue here is the fact the these batteries have almost No electrolyte reserve and that has to be taken into account on any SG readings you take if you have to keep adding water. Any hard sulfate is really hard to break up and cleaning of the pores is even harder. Soft Sulfate on the other hand is easy on a daily basis to remove.

I am sure it is possible to have a cell that will never come up. There are two ways to look at it, either live with it, raise the electrolyte concentration or drill it out and insert a new cell. If the voltage is good on it, ignore it. If it's shorted, then it's got be removed and replaced.


I did have issues that I created for myself because I didn't realize the amount of cycles that it would form the plates ( 100 Cycles ) because I lacked the experience with new Industrial batteries. Even though I recognized that something loony was going on right away because I had Voltage but I couldn't get the SG level to match.

Another thing already mentioned is that having a variable output power supply is almost a necessity to work on these voltage range cells.

Re: My battery soc

gww1 wrote: »

Would something like this work in the outback ac breaker box?

Glen, It will measure the Ah of the AC current, but not the current flowing out of your battery(the DC waste in the inverter will not be included). Shunt based monitors can do this, they don't inhibit flow, much more than your 4/0 wire.

Do you have a shunt in your DC wiring now? Most(all) Epanels have one, do you have a DC breaker box?

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Here's an image I pulled of a trimetric setup, The thingy there with the multiple thin bars is the shunt, the thin 22 gauge(?) wires are from the monitor measuring across the shunt, the large wire is from the battery bank on one side and to the DC Bus on the other.

Here is the shunt in my Epanel, which has the neg bus bar attached;
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Re: My battery soc

Photowhit wrote: »

gww, Hang in there we have a chance for sun Sunday, I've been gone the last 2 almost 3 days and my 24v battery was at 25v as grey skies went to dusk, don't know if the fridge had just kicked off, but it's the only thing running. We have a chance Sunday then 2 more grey days, that might make a week with no visible shape in the sky!, I'll have to call people out of area and ask them is the sun still exists... Bright enough today I'm out of bulk, but when it's rained a couple hours on the zero chance of rain day it leads to depression...lol.

Whit I can really associate with the feelings of helplessness a few days of gloomy weather can bring! Spent 3 months waiting for the spring upturn and with it came the longest stretch of cloudy weather I've ever noticed. The months of May, June & July being the months of the lowest sun saw an average of 3 sunny days for every 1 gloomy day, then came August, September and the first half of October. The higher sun stifled by incessant cloudy weather! Since around mid-August I've been seeing an average of 1 clear day per week, 3 gloomy days and 3 sort of mixed days. Looking at satellite images has become my latest depression inducing pastime - staring hopelessly at the southern ocean churning out cold front after cold front and thrusting them north... The clear weather, if any seems to appear at night which adds to the frustration! There has been a recent improvement but it doesn't appear convincing yet. One can only hope the clear weather doesn't wait until the fall-equinox in March before it decides to stick around for a while..........

Re: My battery soc

Not sure if this was mentioned, but after no recent significant charge, the electrolyte will be stratified in the tall forklift cells. That means the SG reading will be lower than actual. That would mean if you took the SG reading to figure out an SOC from an SOC/SG chart, the actual SOC would be higher than what the chart says because the actual SG is higher than the measured SG due to stratification. How much more? Who knows. It would vary anyway, but up to 5%?

On a side note, I've noticed that if I take an SG reading and then squeeze the bulb somewhat forcibly to eject the electrolyte back in the cell to stir it and then take a second SG reading, the second SG reading will almost always be higher than the first reading.

Re: My battery soc

I guess it's not a secret that I don't put to much stock in Battery Monitors. My time goes back through the Heart Interface and all the Link models with shunts ( built in 1991 and still working ) , Trace and all of the Xantrex re badged units and Vitron BMV's. Some of my issues may be in the way my charging schemes work, a full recharge only occurs every 4-5 days, during those days there could be as many as 10 -20 bulk recharges ( 50 - 85 % ). In the old days you used the Peukert Exponent on the discharge and adjusted the back end, now it's the battery charge factor + capacity + voltage +Time + Ending amps ( if you use them ). If I have to still verify the battery level with the SG's and voltage, what have I accomplished. I just have more numbers that have very little meaning in a different metric . It's like using the Float gauge in a tank or a Flow meter to measure fuel use, if your going to keep looking at the Float gauge then the Flow meter is just extra data. With my batteries I have to stop charging as 1.250 SG and by morning they will come up to 1.265 after resting. If I overcharge the them with longer time or amps I'v just hurt myself and the Batteries. With adjusting all the points I can bring them in line so that they come in line with the Battery Monitor, but they don't stay there, either the temperature or the BCE changes, so it's a every week job.

They may work fine for someone that pulls their SOC to 80% and charges back to 100% everyday, but thats not the way I charge.

Another Issue with some, if the new Monitors ( wiz bang jr and Vitron for sure ) that have the circuit board on the shunt is you cannot allow them to be exposed to the Sulfuric acid fumes or allow any acid to be dripped on them or they are history. I recommend that you take a gallon zip lock bag and cut a small slit and allow the battery cable out the top and tape it and all the other wires come in the zip end and seal them the best you can or you'll major erratic readings or they quit functioning. The Trimetric seems to use twisted pair wires and that is a plus in my book.

I guess I feel that it's kind of like the old parable, you give a man a fish, he can feed himself for a day, Teach him to fish, he can feed himself for life. Being in touch with your Batteries and their health and learning to deal with them is part of having them, It all still comes down to SG level and Voltage.

I also have other issues, 90 % of the Inverter / Chargers I deal with have fixed Charging Algorithms, I can fake the 2% Ending amps baked in by raising or lowering the Battery bank capacity, the charging voltage can be adjusted by removing the the Thermistor on the RTS and replacing it with a potentiometer. So the Battery Monitors end up something else to deal with. With all my setups I use two charging sources that puts charging amps in at least C/25 -30% in Bulk, at gassing I drop one source with a Active high VCS and finish absorb with one source at C/10 - 15%. For my customers it's about Fuel consumed vs battery cost, batteries are expendable when you are talking about $200 a day in Fuel costs vs $100. 6 weeks they'v saved the cost of a new set of Batteries.

In your case if it work's for you and you get good data you can use, then it was a good Investment for what you paid for it. It will be interesting to see how it works with your Fork Lift battery and how you charge, keep us informed.