charging forklift battery

Re: charging forklift battery

I don't think you have too small an array for a 420 ah battery, but I do think you will be too small for an 800Ah battery. 1000watt array at 24 volts(nom) should put out roughly 25 amps an hour w/PSM controller and perhaps as much as 30 with a MPPT (very rough off the top of my head) so about equal on a sunny day to your max draw.

I've been looking into/planning for, a fork lift battery. I too will have a 24 volt system. I'll have @2000watt array supplying the battery.

Most forklift batteries want to be equalized more often than other FLA batteries.

I have looked into this and batteries do appear to be cover as part of a solar system and hence qualifies for the 30% tax credit. NAWS is great and sells a couple Crown forklift batteries Here.

This is likely too big for me (and you) I've found that GB Industries sells direct with shipping in the lower 48. I have a link to the price list from last fall Here. Please note this may be an archived page, I only see a price request on their site currently. Also price does not include a lift bed truck (+$150 for me) an Taxes they do business in most states. Also the lift bed just gets the battery on the ground, not necissarily installed. I have access to a backhoe...

I like the idea of getting a 30% discount on perhaps the last battery I'll need and I'm sure someone will come to their senses and quit this anti "green" credit. I'm just a poor capitalist:D

Monitors Please feel free to Edit if you need to just wanted to pass along info and ideas.

Re: charging forklift battery

Do you reset your Trimetric after each equalizing?

It may be that you've lost some capacity and that your fully charged and the trimetric doesn't realize that your battery bank has reduced capacity... Without checking the Specific Gravity (SG) of the batteries, you might well have created more problems by trying to add charge to a fully charged battery bank.

Just a thought, I realized I'm more of a touchy-feely user and have a trimetric around somewhere but haven't hooked it back up, since taking it done when changing out an inverter. Even Cheap L16's should last 5 years, but perhaps your just due...

My guess is your just letting the charge controller do an equalizing charge each month, this is a maintanance type of equalizing. perhaps you have a single cell getting really bad and need to do a charge based on SG, check out the battery FAQ's here (someone will likely be along to provide a link shortly...

Regaurdless you might well get another year or 2 out of dieing batteries, as they slowly loose capacity.

Re: charging forklift battery

Sorry, you are correct about Trojan batteries, here's a link. Please note this is just the recomended charging rate and on solar it would be rarely exactly there.

Indeed these are guidelines, they also suggest not storing batteries below 32 degrees, while I've never seen that this will cause damage only a reduction of capacity down to the acid's freezing point, typically well below zero. My 5+year old golfcart batteries survived -13 and -10 degree nights this winter and have always been stored outside. As these batteries are beyond their expected life...

I did/do know they (Trojan) recomend only doing an equalizing charge when the SG is well out of specs, While Rolls suggests at least every 6 months. In the past a charge rate of c12 or 1/12th of the capacity of the battery was a desired standard. Indeed my 4 golf cart batteries were charged from roughly 220 watt array for the first year of their life. (12v with 2x2 batteries now 24v string)

It would depend on usage, I would suspect the unmonitored(we haven't heard how eqauizing was done yet) would mix the electrolite for any "undercharging" it also appear the capacity has been monitored closely. Though perhaps the equalizing messes with their special mats?

The sun will shine tomorrow, homemade pizza for lunch in the toaster oven, and brownies while the ovens hot, I can't wait. We've had a week of poor charging/sun.

Re: charging forklift battery

Cariboocoot wrote: »

And of course "storing" is not the same as "using" at 32F or less. I've never had any trouble with batteries left in our -40 Winters because they were in an insulated box and kept charged.

But one of the things we too often forget is that the net charge rate is what goes in to the battery minus what is drawn out at the same time. None of us shut down our systems while they charge, so even with "ideal" targets the actual charge rate will be a tad lower. That's why I don't like to see systems with a potential for only the minimum 5% rate.

I wish I could say I agree with this Marc, but I really never have and can prove it!
First of all people can shut down their systems to charge ( search mode) and many do by not using energy during charge time. It is the winter dance! There are other things in life beside racking up KWH.

The 5% rule is as wrong as is the the 10% rule if it is not in context. If you are not deeply discharging then you do not need that amount of charge. It is the way that offgrid systems grow over time. The point where this goes wrong is when folks use more than they can charge pn a regular basis. It takes discipline but it is easily done.

I know you guys have to deal with general rules here but there are always exceptions! I just had a deep cycle die that just turned 19.

Re: charging forklift battery

for the record, the 5-13% rule of thumb is what is being delivered to the battery and not what the pvs provide, for loads may be on during charge that would take a portion of that % away from the battery. those %s are somewhat arbitrary, for somebody at 4.9% may not have to buy more just to be in that range and will vary by install and even battery type. don't forget that the electrolyte needs to be stirred up on many fla types and, even though one may not need to replace much in the way of ah because of not giving a deep draw, the battery will suffer when only giving back a very small % of charge at all times. does it need to be stirring the electrolyte all of the time? no, but it should be stirred up at some occasions and if you have the pvs to do that occasionally then they will be left on to deliver this capability at all times for who would hold back on some of their pvs just to give a small % charge rate due to a small discharge to the battery? simply put, if it's needed you get it and if you have it you'll use it.
there's a lot of ifs, ands, and buts to this, but i would not say the rule of thumb is wrong given it is to be what the battery gets and the only context may be the charge parameters governing the battery because of its type.

Re: charging forklift battery

Photowhit wrote: »

So I have a @2000 watt array, and will purchase @810 Amp Hour 24 volt forklift battery, so 2000 /35 volt = @57 Amps X .65 (largely PWM controller) = 37 Amps or about 4.5%

So I'll run the test for you and report back, hopefully in 20-30 years...

For the record, I can live with 500 watts of panels for 9 months out of the years, it's really only the 6-12 weeks of summer that I use the extra. During that time I also have additional charging hours. I will play though, it will be neat and save propane to run the toaster oven in the evening, though I'll still likely only do this with a sunny day to follow.

A reminder on the forklift charging, we are responding to forklift charging thread... They like to be equalized more often.

Thanks! I thought there were still a few who thought of specifications as a guide to interpreting characteristics and not cheating. I started with 200 watts for several years and have worked my way to near 3000 watts. I never use anywhere near the recommended charge rate because I do not use much energy, unless I want to when the sun is out!

About half of the 45 offgrid folks I am involved with are small and grow over time. The other half are turnkey systems where the moderators advice is valid. Some very beautiful systems in even more beautiful places.

Photowit, I can't run the toaster in the evening until I win the bet for making this bank last 14 years. It is a very, very nice bet BTW, with a very old mentor.

Re: charging forklift battery

Sunny lunch time toast or midnight snack toast (battery toast)?

Ralph

Re: charging forklift battery

Cariboocoot wrote: »

I hate to sound like a broken record, but Trojan does recommend a peak charge rate of 10% for these batteries in order to remix the electrolyte and reduce sulphation.

Marc, I do not want to challenge you, BUT, in my experience, the mixing of electrolyte does not really occur during Bulk, but rather, in Asorb. And, really, then in the later portion of the Asorb cycle, when the cells are most vigerously bubbling.

The C/10 (or greater) charge currents are reputed to open up more of the active plate material, which helps maintain capacity, and IMHO, this does not need to be done in each charge cycle. Probably monthly would suffice quite well.

For battery banks that are lighty-cycled (shallow depth-of-discharge), The bank might not even come close to accepting the maximum available PV charge current, as the charging occurs when the sun has not reached the optimum angle. C/10 might be available at local zenith of the sun, but, the bank was fully charged at a lower current. perhaps hours before the local solar maximum for the day.

EDIT: However, generally, Forklift batteries need higher charge rates than other flooded batteries. Always follow the guidelines specified by the manufacturer of the specific battery.

Just my personal observation, MMV and so on. Vic

Re: charging forklift battery

Hi Marc,

YES, you are correct about Trojan's recommendations. But, here, have often seen the statement about high Bulk currents mixes the electrolyte. In my limited experience, the there appears to be little bubbling aciton in Bulk, but is pronounced in last part of Asorb and quite prominant in EQ. I do believe that the mixing mechanism is the formation of bubbles -- gassing.

That was my point, but it is reallty a bit of a tangent from this topic.

My C/10 charge rate can only come from my largest genreator, which is used every few months to do heavy charging.

Trojan does show 10-13% C20 charge rate for the entire Bulk cycle. And, a bit curiously to me, they show Bulk charges to 90 % SOC, rather than 80% as end of Bulk, noted by some other manufacturers of batteries. It IS always best to follow the advice of the manufacturer of one's specific batteries.

YMMV, Vic