What does it cost to charge the batteries on my electric forklift?

Sorry I have not posted a blog in some time. I have just been busy with sales training, presentations, traditional work stuff and honestly took some time to focus on some life stuff. However, now I am back and will be sharing a short blog today about how to calculate how much you spend per month in electricity to charge your forklift batteries.

If you are like most companies, your electric bill is not broken out into office bill, plant bill, battery room bill, etc. So when you ask a client about their electricity use, they normally have that confused deer in the headlight look. It's like I just started speaking German to them and they speak french. However, if you can go in there confidently and share with them your knowledge of batteries, chargers and what it cost to charge (1) battery, you will be that much further along than the other guy!

So where do we start? Well first you have to obtain some simple info: (1) How many battery's do they use per truck? (2) What is the amp hour of the battery? (3) How many volts is the battery? (4) How many shifts do they have or how many times per day they change the battery? (5) How many days per year they work?

OK, so for this example lets say they have a 36V battery, 1000 ah, 3 shift operation & they change the battery every shift and they work 360 days per year. So to determine the amount of electricity they use per truck per year, here is what you do: Take the battery voltage x amp hours = Total Watts... so 36v x 1000 ah = 36,000 watts. Then you take your watts divide it by 1000 = kw... So 36,000 / 1000 = 36 kw. IS that it? NOPE!! Now we have to figure out battery charger efficiency. What is that? Basically it tells you how much power goes into the battery after it comes out of the wall and goes through the charger. Another way of looking at it is out of every dollar you spend how much of it is lost and how much is used. I will post another blog about charger efficiency tomorrow. So now that we have our kw, we need to divide that number by the charger efficiency. I normally use .65 - .75 or 65 - 75% efficient. Lets use 75% efficient. So take 36 divided by .75 = 48kw. Since you have to put more power in the battery due to energy loss, you have to put 48kw in to get the battery back above 80% charge.

So now what? Well if you live in TN where I am at, we use .095 cents per kw hour. So take 48 x .095 = $4.56 So the cost to charge (1) battery out of the (3) battery's for the truck in the example is $4.56 So the cost to charge (3) battery's x 360 days = $4,924.80 So (1) truck, in a (3) shift operation cost $4,924.80 per year in electricity. So if you have 25 electric trucks with the above listed specs, it will cost you $123,120.00 per year to charge them. That is operating cost, money you will never get back. This is why alternative power sources, fuel cells, high frequency, are so attractive to companies. The less they are dependent upon the electric company, the better off they are.

I hope this gives you a better understanding about how to figure up battery costs and how to apply it to your customers fleet. Most customers do not know what they spend each year in electricity. Now you know how to help them figure it out!

Do We Really Spend That Much?

Before I ask the question, I will tell you the answer is YES! Here is the question now. In a business that is dependent upon electric material handling products for their day to day activities, are labor and electricity? Now that you know the answer, let me dive into this a little bit.

The average time to change a battery is 20 - 25 minutes plus 3 - 5 minutes to get to the battery changing area. So on the low end, in a 2 shift operation, you are looking at 46 minutes of battery changing time. So if your forklift operator makes $20.00 per hour, you have a 2 shift operation working 360 days per year, you are spending roughly $165,000.00 just in labor.

Now a quick look at the electricity. The cost to charge 2 batteries every year on a 2 shift, 360 day operation with just 30 electric walkie riders is a little under 60k per year. So labor and electricity is about $220,000.00 per year. This is what I like to call "Unrecoverable". Money you will never see. This blog is just to get you thinking. I will write more later about how I calculate these numbers so you will be able to look at your fleet and begin analyzing your finances.