Forklift battery help and system ideas please

Stone MasonStone Mason Registered Users Posts: 16
Hi all, great to find out about this forum... i need a bit of help/inspiration for my system.

Ok first off, got some 2nd hand forklift batteries today... i have not hooked them up yet as i need some input of my system design.

I do need some info on maintenance of forklift batteries, they are 2v cells, bloody heavy and i have not given them a charge and are resting at 12.6v
I have read that people equalize the 2v cells... what is this? how do you do it on a pure off grid situation.

Now i will explain my existing system and my plans.

I live in a house bus off grid in Nelson New Zealand.
I have currently 1x120w panel and 3x40w or so home build panels... am building many more though.

Also have a 500w 24v EC turbines wind turbine running at 12v.
http://www.ecindustry.com/product/Clean%20Energy/Wind/wind-product-Horizontal%20Axis%20Wind%20Turbines.html
I am in a very low wind area and the max i have seen it at is just over 2a output at 12v :grr

These are currently hooked up to 2x 220ah batteries and a 30a BP solar controller.

I have a dump load connected to the turbine side so when the batteries get to 13.5v it dumps to another battery bank of 3x 105ah 2nd hand batteries which are in my garage for lighting.
This seems to keep them topped up as the batteries resting voltage is 12.6v but drain to 12.4 very fast (do the job intended though). i plan to re-design this system so will be going.

I have 3 inverters, 60w, 600w, 1500w pure sine... i rarely use them as i have nearly everything in 12v, 12v T.V dvd combo, 12v plug for laptop, 12v stereo, 12v LED lighting, 12v pump, 12v cell phone charger etc
I only ever use a inverter if i need to use my printer or something which is almost never.

Ok so that is my current system... i want to know how you guys think i should add my extra forklift battery and panels.

From what i have found with my current system is on a sunny day the batteries start floating at about 1PM... solar puts out 12-16amps in full sun and then by 1PM only about 2amps is going to the batteries as they are floating.

Would you guys suggest as i am adding more panels and do not want to connect the battery banks together just having a completely separate system? ... well 3 systems.

Please let me know if you think this plan will be good...

System 1.
240w+ or so PV and 30a controller 440ah batteries.

System 2.
Another 240w+ or so PV 20a controller and forklift batteries.

System 3. 120w PV 500w turbine 10a controller and 3x 105ah batteries with a voltage switch to run my 12v fridge... draws 4.5A max.

On the output side of system 1&2 will have a switch to switch between systems before my fuse board etc.

I think this is a good way to let my batteries get a good charge letting them be able to float for a week or so and will switch between systems each alternate week...

What do you all think of this?

Thanks in advance for your help.

Comments

  • Stone MasonStone Mason Registered Users Posts: 16
    Re: Forklift battery help and system ideas please

    Oh, i will post some pix of my system etc, my internet plan is only 2gig and bloody expensive for mobile broadband in New Zealand so have to go to the library to upload pix.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Forklift battery help and system ideas please

    Welcome to the forum.

    Do you have a capacity rating for your forklift battery? Without an Amp hour figure (which may be difficult to find for the RE standard '20 hour' rate as that is not its intended use) it is difficult to plan the use and recharge.

    Equalization is the process of pushing the battery Voltage higher than normal charging and holding it there. It helps negate sulphation and thus keep the Specific Gravity of the cells equal. Hence the name.

    You'll want to check out the Battery FAQ's: http://www.windsun.com/Batteries/Battery_FAQ.htm

    Some people on the forum do run forklift batteries and should be able to give valuable insight.

    My personal evaluation is that you've got quite a mixture of equipment which is not likely to perform optimally because of its diverse nature.
  • Stone MasonStone Mason Registered Users Posts: 16
    Re: Forklift battery help and system ideas please

    On the forklift batteries it has the following markings.

    Century Yuasa
    Tubular plate
    2005a 6047

    The size is:
    H400mm L155mm W155mm

    Its hard to estimate my power demands for workings... being self employed sometimes i cant be bothered working so i play online poker all day : )

    Also panel wattage is different in NZ from rated as we have brighter sun or something... here in Nelson we have the most sunshine hours in NZ also.

    What is the norm for people running two different battery banks for 1 system? a battery isolator?

    Also how would one equalize a battery on a off grid situation?
    I have read you need a special battery charger... but how would you run it when the battery you are equalizing is your power source?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Forklift battery help and system ideas please

    In NZ I bet the difference is the derating of panel nameplate. Normally you could expect an average of 77% of the nameplate on the controller output. But up at my elevation it's more like 80-82%. You probably have this same advantage. Otherwise, insolation is the same everywhere. It's the local atmospheric conditions that make the variations (including high or low temps, pollution, et cetera).

    One common solution to using separate banks for one inverter is a battery switch like this:
    http://www.solar-electric.com/basw1300amp.html
    Although it has to be switched manually. With separate charging of each bank this becomes less of a problem.

    Equalizing off grid is usually done by bulking up the battery first with a generator, then switching the charge controller to EQ. Not all charge controllers have this function.

    I do not know the specs for the forklift battery you name. Perhaps someone else here does.
  • Stone MasonStone Mason Registered Users Posts: 16
    Re: Forklift battery help and system ideas please

    Yea, i was watching one of those sort of switches here:
    http://www.trademe.co.nz/Browse/Listing.aspx?id=373386556

    So are you suggesting having 2 seperate systems (2 charge controllers) and using the switch to switch outputs of each controller.
    Or are you suggesting having 1 system and a battery isolater?:
    http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Batteries-chargers/auction-375127877.htm

    Hmmm if i did the 2nd option i would have to connect the loads directly off the batteries rather than the output from the charge controller... this would not be a probelem but just cannot keep an eye on usage or use the handy switch on the controller to turn the system off.
    By searching the intronet for battery specs the only simillar ones are 330ah... what do you think? is that for each 2v cell? so 330x6=1980ah?
    Seems pretty big! cant be right : (
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Forklift battery help and system ideas please

    For different batteries (of any type) it's best each have its own array and charge controller. This is because the charging of even similar banks won't be identical. Unless you put them together as one bank to begin with (all the same battery type and age) they'll have different needs for charging. With dissimilar batteries it is a must. For instance you can't parallel a 12 Volt 100 Amp hour battery with two 6 Volt 225 Amp hour batteries - you either over charge the 100 by putting 22 Amps to it or under charge the 225's by limiting the current to 10 Amps. Makes for short-lived batteries.

    If you have one bank all of a type with its own set of panels and controller, it will be kept charged according to its needs. Another bank of different batteries (capacity, age, not Voltage) kept charged can then be switched in/out to supply the same inverter. In a pinch you can hook them both together.

    Battery isolators would not be the best choice, even though automatic. They're designed to recharge two batteries from one source, as in a RV where the alternator primarily charges the starting battery then switches in the 'house' battery to keep it up.

    Depending on what your actual output needs are, you could have fully independent systems. For example, one small 12 Volt system supplying lighting power. Another (possibly higher Voltage) to run critical things like the refrigerator. That would mean if someone left the lights on the refrigerator system wouldn't go dead at 2 AM.

    As for the 2 Volt cells ... there are some that are roughly 1000 Amp hours each. Yes, you read that right. But when you put six of them in series to make 12 Volts you have 1000 Amp hours at 12 Volts; series connections mean Voltage goes up but Amps remain the same. Parallel connections it's the other way 'round.
  • SCharlesSCharles Solar Expert Posts: 123 ✭✭
    Re: Forklift battery help and system ideas please

    We only have one bank, but that one is a set of forklift batteries. Ours are an 1875 amp hr. set that have been in use for a bit over 20 years, running our house [purchased new]. We recharge them from PV only, no generator. Our array is now around 2000 w. but was only 900 w. for the first 14 yr. of the battery life [I was ignorant that this would be considered too small, but we've been ok all along]. We are up at 8500 ft MSL, so perhaps we have gotten by with a bit smaller array that others could, I don't know. But we do not use anything but PV to provide electricity and battery charging.

    I sized our bank to have a maximum of somewhere around 20% discharge before recharging. Or that was my estimate way back when. Twenty yr. later, we do use more electricity but almost all of the additional is used during sunlight hours.

    These forklift batteries can really last a long time.
  • keyturbocarskeyturbocars Solar Expert Posts: 375 ✭✭
    Re: Forklift battery help and system ideas please

    SCharles, Over 20 years! That is impressive! How often do you equalize the battery bank? How has battery maintenance been over the years (watering)?
  • SCharlesSCharles Solar Expert Posts: 123 ✭✭
    Re: Forklift battery help and system ideas please

    Maintenance has been nothing more than adding distilled water, which I check about twice a year as experience with these batteries has shown more frequent checks are not necessary. I have never had to add more than a cup or two of water to any one cell.

    I didn't equalize for many years. I didn't know about it. I thought I did, but later found out [partly through reading forums such as this one and some books and articles such as found in Home Power magazine and etc.] that what I was doing was just bringing up an overcharge situation for a couple hours, maybe once a year. Once I realized how much more was involved, I did equalize but only, again, about once a year.

    Additionally, I did the usual cleaning up of the battery tops that one does with any lead acid battery.

    I have been using HydroCaps since the batteries were new. That is likely why my water usage has been so minimal. A gallon of distilled lasts me over a year.

    There was one incident where the old controller I had then malfunctioned. The mechanical shut-off to the batteries, like the solenoids used in cars for the starter, locked in the closed position. I never figured out why. I had to open the contacts and clean them up with emery paper, then they never locked shut again. However, while they were locked up, I didn't realize it for a while and the batteries were above the recommended voltage for some time. I don't know how long. I discovered the problem when I kept smelling hot plastic, which turned out to be the HydroCaps melting. They were all destroyed, the caps, and had to be replaced along with more water than usual. However, I could detect no damage to the batteries, amazingly enough. But it was scary and I ultimately installed some new Outback charge controllers.

    When I purchased the batteries, the dealer [who usually sells to warehouse and etc. for forklift use] told me that the usual habit of users was to run the battery banks virtually dead during a work shift and then stick them on a powerful charger which would go all night, or another 8 hours. So, take the batteries down low and rapidly bring them back up. They use 14.2 volts as a final level, he said. The average lifespan of the batteries, used this way, according to his experience of selling the users new sets, was about 6 to 7 years. At least, that's what he told me. He was afraid I would be unhappy with the batteries used in a PV system since I would not be sticking them on a high-powered rapid charge system.

    But I have been very pleased, obviously. I did not equalize them properly for fifteen years and had the one incident with the controller and still the batteries have lasted and lasted and are still working. They are not as good as new, of course, but they are still working. They are installed inside our house so they are not subject to much of a temperature swing and are never cold or hot. Nor do they suffer any mechanical wear from being on a moving vehicle. So I am quite happy with forklift batteries....

    I haven't done any price comparisons for forklift batteries and dedicated, designed-for-solar batteries in some years, but back when I was buying mine, the forklift batteries were less pricey than the solar ones. Don't know whether that is still the case. Plus, I could get them locally and not have to truck in from somewhere far away. However, the forklift batteries are so heavy and difficult to move around, one must consider that when deciding to go with them. My six cells each weigh 330 pounds and they are brutal to move.
  • keyturbocarskeyturbocars Solar Expert Posts: 375 ✭✭
    Re: Forklift battery help and system ideas please

    Thanks for the details SCharles. I have a set of AGM's and when they are dead, I might consider a forklift battery. It sounds like they have served you very well!!!

    Edward
  • Stone MasonStone Mason Registered Users Posts: 16
    Re: Forklift battery help and system ideas please

    Thanks for the info there mate,
    How do you equalize your batteries? do you have mains power too?

    I have been doing a bit of reading about forklift batteries on battery supplier sites, they basically say the plates are the thickest of all types of batteries... thats why they will last the longest after a thrashing.
    Loads that a forklift would put on them must be pretty massive.

    I gave mine a charge today for about 3 hours from my little generator... hooked to a 17amp 3 stage charger... after 3 hours it was up to 13.2v and after disconnecting and leaving it it dropped back down to 12.6v

    I wanted to see how good it actually is and how fast it will drain.

    Hooked up my garage system, led lights, stereo,60w inverter with battery drill charging and also my 1500w inverter with 750w power drill.

    When i switched it on the battery voltage quickly dropped to 12.51... i ran the drill for about a total of 20min and left all the other stuff on for about 2 hours... when went to switch it off the voltage was at 12.49v... then switched it all off... voltage started climbing back up... after about 1 hour it was back up to 12.6v, indicating that i hadn't even used any power.

    So this all seems good, i just need to get the weather man to forecast some bloody sun so i can give them a good charge from my solar and see the actual resting voltage, its rainy season here at the moment : (

    So the other systems questions i had have been answered, thanks for that : )
    I will go ahead and order more charge controllers and try to find a suitable voltage switch for my fridge.

    Have you guys got any suggestions for a suitable, affordable equalizer charger?
  • Stone MasonStone Mason Registered Users Posts: 16
    Re: Forklift battery help and system ideas please

    Some pix for you guys...
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Forklift battery help and system ideas please

    Just a little explanation.

    You can equalize from solar alone. You do not need large amounts of power to do an EQ; just enough to completely charge the batteries. The EQ cycle doesn't take a lot of current (like bulk charging); it is controlled elevated Voltage for a fixed period of time to try and correct differing specific gravity readings between cells.

    Are you planning on putting a forklift battery into an RV? Could be a tricky install. They aren't the most manageable things in the world.
  • Stone MasonStone Mason Registered Users Posts: 16
    Re: Forklift battery help and system ideas please
    Just a little explanation.

    You can equalize from solar alone. You do not need large amounts of power to do an EQ; just enough to completely charge the batteries. The EQ cycle doesn't take a lot of current (like bulk charging); it is controlled elevated Voltage for a fixed period of time to try and correct differing specific gravity readings between cells.

    Are you planning on putting a forklift battery into an RV? Could be a tricky install. They aren't the most manageable things in the world.

    Ah ok, it must take a long time to do it with solar as the charge controller would be topping off for weeks to get to a full charge... correct?

    Batteries are already installed, did it yesterday... chopped all the links and made new ones so i could move each cell separately... would have been almost impossible to put them in the lockers without chopping the links.
  • BB.BB. Super Moderators, Administrators Posts: 32,641 admin
    Re: Forklift battery help and system ideas please

    Problem is that you don't want to take weeks to recharge a lead acid battery bank... If it is below ~75% state of charge, the cells are starting to sulphate (lead sulphate crystallizing within hours)--and once the crystals form, that material is never available for recharging again (battery looses capacity).

    So--the idea is to quickly (next day) get the battery recharged >75% state of charge.

    So, depending on how deeply you discharge the battery and how much charging current you have (solar, generator, utility power)--tells you how long it will take to get above ~75% state of charge... Plus, ideally, you want to get >~90% state of charge a couple times a week.

    Given that fork lift batteries are typically large, you need a lot of charging current (and power) to recharge properly recharge forklift batteries...

    Also, forklift batteries tend to have more self discharge than normal deep cycle batteries (and much more than AGM--which are very low self discharge for lead acid chemistry batteries).

    Gets back to the recommend 5% minimum charge rate if at all possible.

    I don't remember you saying what AH rating your forklift bank is--But assuming 1,000 AH cells at 12 volts and 5% minimum rate of charge:
    • 1,000 AH * 0.05 = 50 amp minimum charge
    • 1,000 AH * 14.5 volts charging * 0.05 rate of charge * 1/0.77 solar eff = 942 watts minimum of solar panels recommended
    The recommended rate of charge for solar panels from us is around 5%-13% of AH rating rule of thumb for solar panels. (solar panels are expensive and above ~13% rate of charge, usually less cost effective).

    For AC battery chargers, around 5%-25% rate of charge (AC battery chargers and gensets are less expensive--but watch too large of AC Battery charger+genset--can end up wasting lots of fuel for last 20% of charging from genset).

    Again, just initial rule of thumbs to quickly estimate the size the system. Can always adjust to your specific needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SCharlesSCharles Solar Expert Posts: 123 ✭✭
    Re: Forklift battery help and system ideas please
    Ah ok, it must take a long time to do it with solar as the charge controller would be topping off for weeks to get to a full charge... correct?

    No, my forklift batteries are fully charged back up daily, assuming, of course, a sunny day. This is with PV alone. Now, I do not discharge mine to less than 75-80% capacity. Or, to make that very clear, I sized them not to discharge more than about 20% under normal conditions. [Of course, with some weather situations I cannot help but have them discharge more than that, but not normally.] But they are 1875 amp hr. and still charge up daily. According to the dealer, the usual charge method is, yes, to use a very powerful charger for several hours. But, then, those battery sets are discharged way down during the course of a work shift. Or, they often are. I've worked in situations where guys would drive the forklift til it barely would move or came to a stop, then either crept over to the charging station or towed the lift over with another lift. In a home-PV system, at least in mine, they are never asked to be discharged so low. Which is probably a lot to do with why ours here have lasted two decades. They appear to built very tough and able to last a very long time if not abused.
  • petertearaipetertearai Solar Expert Posts: 469 ✭✭✭✭
    Re: Forklift battery help and system ideas please

    Hi Bill


    Problem is that you don't want to take weeks to recharge a lead acid battery bank... If it is below ~75% state of charge, the cells are starting to sulphate (lead sulphate crystallizing within hours)--and once the crystals form, that material is never available for recharging again (battery looses capacity).

    Question...... Will an Equalization reverse sulphation ?

    Regards Peter
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • BB.BB. Super Moderators, Administrators Posts: 32,641 admin
    Re: Forklift battery help and system ideas please

    Nope--nothing will reverse sulphation (some folks hthink that a desulfator can reverse sulphation--but that is probably not correct).

    For forklift batteries--vigorous charging/equalization can knock the hardened sulphate crystals off the plates and onto the bottom of the battery case--and the batteries can still function because of the extra thick plates forklift batteries start with.

    -Bill

    PS: I am no battery expert--just my limited understanding of the issues.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Forklift battery help and system ideas please

    Oh dear; I'm going to contradict Bill. That probably means the world is coming to an end. :p

    Equalization does indeed knock the sulphor off the plates. But sulphation is plates coated with sulphor, preventing them from working as electrodes (sulphor works as an insulator in this instance). So it does reverse sulphation to a certain extent. The sulphur then remixes with the water, strengthening the acid mix (higher specific gravity) and improving the electrolytic action.

    But it isn't perfect: not all the sulphor can be recovered this way. Some will end up as crystals on the bottom of the battery, along with some of the lead. Plate erosion is inevitable (do not confuse with plate corrosion) as is the loss of use of the "soft lead" packed into the waffle or waveform plates. You can slow down battery degradation, but you can't prevent it. The heavier-duty the battery is to begin with, the longer it lasts. But allow it to sulphate and it can lose capacity very quickly.

    I do agree about the desulfators; no real scientific evidence that they work. Sales are based on a theory of operation only. It would be practically impossible to test this, as you would need several identical batteries subjected to identical charge/discharge over several years. One set without desulfator, one with, and another with the desulfator used to try and recover. Repeat test at least three times to get viable results. Good luck with that.

    Bill will now ban me. Goodbye. It's been fun. :p
  • BB.BB. Super Moderators, Administrators Posts: 32,641 admin
    Re: Forklift battery help and system ideas please

    A bit of symatical difference... You are talking about being able to reverse one of the effects of sulphation (removing the "insulating" crystallized lead sulfate which reduces battery efficiency/ability to produce/absorb current). Which is true.

    However, I was addressing the larger issue that once the lead sulphate has crystallized--there is nothing that can be done to return it to an active form.

    Battery capacity is still lost in the end.

    So--no banning for you today. Punishment will be working forum spam patrol for the obstinate Canadian. :p

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Forklift battery help and system ideas please
    BB. wrote: »
    So--no banning for you today. Punishment will be working forum spam patrol for the obstinate Canadian. :p

    -Bill

    But ... I do that now. :confused:
    Ah well ... "Plus ça change, plus c'est la même chose." :p
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Forklift battery help and system ideas please

    "So--no banning for you today. Punishment will be working forum spam patrol for the obstinate Canadian."

    -Bill

    But ... I do that now. :confused:
    Ah well ... "Plus ça change, plus c'est la même chose." :p

    now that gave me a chuckle.

    hey, bill. you do know he can ban you?:confused::cry::p
  • BB.BB. Super Moderators, Administrators Posts: 32,641 admin
    Re: Forklift battery help and system ideas please
    niel wrote: »
    hey, bill. you do know he can ban you?:confused::cry::p
    Promises, promises....

    -Bill :-)
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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