Best 48 Volt Charger

[Sunking]

Sunking, I included a terrible example and you focused on it, even to the point of basing your comments on a solar charging instead of AC chargers..

It does not make any difference if it is Solar or AC charging. You do not control charging amps directly.

Look I know what you are asking for. Fact is unless you are willing to spend alot of money, you cannot have it, nor do you need it. You simply do not understand how a battery charges, or the physics that control it.

It is real simple. You control Charge Current by buying the AC charger with the current and voltage you want from what is available, and for Solar it is controlled by Panel Wattage with respect top controller capacity. It is a FIXED value. You do not control it. Example if you buy a 48 volt 15 amp charger, that is exactly what you get. That charger will charge at 15 amps until the battery voltage reaches the voltage set point in the charger.

Same for solar with a slight twist. Charge Current is determined by the available panel wattage and battery voltage. You do not control it. Example if you have 1000 watts and a 48 volt battery, assuming the controller is designed for it will have 1000 watts / 48 volts = 21 amps. If that is too much, you lower the panel wattage. If it is not not enough, you have to add more panel wattage.

It would be nice to have a Charger like you want. But it does not exist. As close as your going to get is a Hobby Charger made for Radio Control Planes, Helicopters, and Trucks. But there are some catches like the highest voltage is going to be 36 volts at the highest current around 40 amps. Those kind of chargers will charge a single cell AA battery at 1.5 volts @ 10 ma up to 36 volts @ 40 amps and everything in between. The second catch is you must have a DC Power Supply of the right voltage and current capacity. Example Revoletric make a Charger called PL8. It will charge any battery up to 8S LiPo or 33 volts @ 40 Amp. To use it to full capacity requires a 1400 watt DC power supply operating at 24 volts up to 50 amps. You are looking at $500 investment and still not have 48 volts.

However you are not going to find many if any AC chargers that will do 48/24/12 with both adjustable voltage set points and current control. Two reason. No demand for it, and it would be very expensive. You have sen it already. Example the Iota is a great charger and they make 1 flavor for 48 volt batteries fixed at 13 amps. Only thing you can adjust is the voltage to make adjustments from Gel to FLA. There is no current control, it is fixed at 13 amps. Can be used on as small as a 40 AH AGM up to 160 AH FLA and everything in between.

If your battery is so small it can only handle 5 amps of charge current, you do not buy a 10 amp charge. You buy a 5 amp or less. I think you keep get hung up on Marketing Terms and Sales Buz Phrases like 3-Stage and 4 STAGE.. Batteries do not need 3 or 4 stages. 3 and 4 stage chargers are OK if have all the time in the world and use an AC charger. It is not the best charging algorithm, just the most expensive, and not fast.

Optimum and most efficient battery charging is charging as fastest rate and highest voltage the manufacture recommends, , usually C/8 to C/6, with a Constant Current/Constant Voltage (CC/CV) until charging current tapers off to 3% of C, then terminate. So if that happens to be a Trojan 100 AH battery you want charge at 17 amps (C/6). to 14.83 volts until current tapers off to 3 amps, then terminate. Can you charge at a slower rate like C/12? Yes sir you can, it wil just take a lot longer and use more total energy. Go below C/12 and you risk never getting the battery fully charged.

The Elcon charger wil not do what you want. There is no charger to do what you want because there is no need for one. No one is going to make a charger that no one wants or can use. So why would you want to make charging painfully slow when there is nothing to gain?

But I will tell you what. For $2000 I will make you a battery charger that will charge up to 20 amps on 48 volt, up to 40 amps @ 24 volts, and 80 Amps on 12 volts. Real easy I go buy a 48 volt $300 Golf Cart Battery Charger, and add a circuit board to give you 24 and 12 volts at any voltage or current you want. You will have a 1 of a kind charger. You wil be able to charge as small as a 12 volt 1 AH battery up to a 48 volt 240 AH battery.

[Sub]

Hi folk, I really know nothing about the topic, but thought you may be interested to look at this multi voltage, selectable, battery charger I found listed for sale on the New Zealand equivalent of eBay - TradeMe -

http://www.trademe.co.nz/building-re...1392300038.htm

Doesnt say where it is made, and I haven't Googled for info about it. Found the listing while I was searching for a generator for sale. Note that the price is in $NZ which is less than $US. Should probably be available in other countries as well.

[AzRoute66]

Sub, thanks for the input. I love the fact that it has METERS for voltage and amps, and the selector switch for nominal voltages initially looks very promising but in the end it does not provide the flexibility in voltage setpoints that I would like to see. Also, it needs an input voltage/service that is way larger than I would have available. Appreciate the thought.

Sunking, I really do understand how constant current/constant voltage translates into the 3 stage charging profile and how the 'absorb' stage is controlled by the internal resistance of the battery, I also took ECE 101 - Intro to DC circuits when I matriculated at the MIT of the West. I also understand that the underlying notion of where/when/if you enter/bypass the 'absorb' phase is as much of a matter of a time shift than it is anything else. Just for your info, I saw a Trojan reference just today that said C/5 max for FLA and and Rolls reference to a C/4 max for FLA. Apparently mixing in a little carbon in the negative plate makes it act a little bit more like an AGM. ALL OF YOU PEOPLE GO BUY NEW CHARGERS.

[Sunking]

Sub, thanks for the input. I love the fact that it has METERS for voltage and amps, and the selector switch for nominal voltages initially looks very promising but in the end it does not provide the flexibility in voltage setpoints that I would like to see. Also, it needs an input voltage/service that is way larger than I would have available. Appreciate the thought.

Sunking, I really do understand how constant current/constant voltage translates into the 3 stage charging profile and how the 'absorb' stage is controlled by the internal resistance of the battery, I also took ECE 101 - Intro to DC circuits when I matriculated at the MIT of the West. I also understand that the underlying notion of where/when/if you enter/bypass the 'absorb' phase is as much of a matter of a time shift than it is anything else. Just for your info, I saw a Trojan reference just today that said C/5 max for FLA and and Rolls reference to a C/4 max for FLA. Apparently mixing in a little carbon in the negative plate makes it act a little bit more like an AGM. ALL OF YOU PEOPLE GO BUY NEW CHARGERS.

I have always said Trojan and Rolls can be charged faster. All I am telling you is there is no one charger better than the other, and there is no perfect charge rate. In fact there is not one charger made that can tell if the battery is fully charged or not. It is impossible. There is no algorithm you can apply that guarantees a fully charged lead acid battery. There is no one correct charge rate. Anything from C/12 up to the max charge rate the manufacture specifies. What changes is efficiency, gassing, and time. If you want to charge at a low rate of C/12 you spend a lot less time up and above gassing voltage of 2.4 vpc. That means you use less water, but is going to take a lot longer and is less efficient. You have to make a trade-off. If you want to charge efficiently and dissolve as many lead sulfate crystals as possible, you charge at higher rates and above gassing voltage. Again the trade-off is now you use more water.

There is only one way to fully charge a battery, and the manufacture actually tells you how. They just fooled you and call it different names like Equalize, Boost, or Refresh Charge. You apply a Constant Voltage which has many names like Float, Absorb. Equalize, Refresh. Daily Charge and the list of names goes on. The voltage will range from 14.4 to 15 volts and leave it on charge until your Temperature Compensated Battery Hydrometer tells you the battery is fully charged. That is the only way to tell if the battery is fully charged up or not. I can also tell you that works on any 12 volt lead acid battery from as low as 13.8 volts up to 16 volts. Pick any voltage you want, and you can fully charge your battery. Charge at 13.8 volts A C/10, and it will take 24 hours, charge at 14.4 volts @ C/10 and it take 12 to 14 hours, charge at 14.8 volts @ C/10 and get it down to 10 to 12 hours. Take note. Each was C/10 charge rate, what changed was the voltage and made time disappear. The higher voltage was more efficient. it just uses more water.

Here is the bottom line of lead acid batteries. There is a Razor Thin Line when it comes to charging batteries. You have to pick which side you want to be on as you cannot stand on the line. You can choose to undercharge (sulfation slow death) or overcharge (Corrosion and Sudden death). You pick between the two evils, and overcharge is the lessor of the 2 evils. Over charged batteries ruh at higher capacity, less likely to freeze, Resistance aging slows because sulfate is not allowed to collect and harden, and will longer than undercharged batteries.

Think of your car battery. All of them are over charged. They float at 14.2 volts. Everything is great for 3 to 5 years, then one day it won't turn the engine and your battery had a Sudden Death. So you want a fully charged battery, forget all the gimmicks, get a simple CC/CV charger and charge until your hydrometer says stop. Your 3-stage charger cannot do that. That is why Trojan says EQ once a month to fully charge your battery.

I wished I could give you a laundry list of chargers that match what you want. I cannot do that, there are none I know of, and the ones I do know of will not go up to 48 volts. So if you want a 48 volt charger, you have 30 options to pick from. Option 1 is the lowest cost, and option 30 is the highest cost.

Option 1 a 1 amp charger.
Option 2 a 2 amp charger
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.
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Option 30 is a 30 amp charger as large as they can make to work on a 120 VAC wall circuit. Voltage Is irrelevant as long as you can adjust it from 54 to 63 volts. You get to decide how many FIXED amps the charger can provide. The larger the amps, the larger and faster you can charge. That is what you must deal with like it or not. If it were me would be a good ole 48 volt 20 amp Golf Cart charger. At 20 amps is good for 50 AH AGM up to 240 AH FLA. Or do something else.

[AzRoute66]

[...] and there is no perfect charge rate.

[AzRoute66 passes peace pipe to Sunking, and squints through the haze.]

Sure there is, an adjustable/settable one.

[AzRoute66 exclaims "AMEN" to everything else Sunking is now saying and has ever said and 96% of what he will say in the future.]

Your 3-stage charger cannot do that.

[AzRoute66 accepts peace pipe back from Sunking, inhales deeply, and mutters...]

"Um, there is no such thing as a three stage charger."

[Sunking]

[AzRoute66 passes peace pipe to Sunking, and squints through the haze.]

Sure there is, an adjustable/settable one.

Good luck finding one. I will not waste any more of my time finding something that does not exist. You can waste your time. Me thinks you cannot see the Forest because the dang Trees block your vision.

[AzRoute66]

Perhaps the forest is blocked by the dang trees, it happens to everybody including me.

But you have used every saw in your inventory, and until something else cuts down that critical tree I'll go on thinking that adjustable/settable is better than fixed, in very tangible and useful ways.

[Sunking]

I'll go on thinking that adjustable/settable is better than fixed, in very tangible and useful ways.

It would be great. Just how many of those $500 to $1000 battery chargers are you going to sale? That is why you are not finding many if any at all. You have to deal with that.

Second it does not buy you much flexibility. An AC charger is limited to 1500 watts maximum power. So you can find up to a 30-Amp Charger at 48 volt battery. You would pay up a bit to get 30 amps. More common is 15 to 20 amps for golf carts or 750 to 1000 watts. So if you bought a 20 amp 48 volt charger, it has limits. The smallest battery it can charge in a day is 80 AH, and the largest is 240 AH. It wil charrge a 48 volt 80 to 240 AH battery. So what does having a Variable 1 to 30 amp current really buy you?

All it buys you is the ability to charge a 48 volt 1 AH to 79 AH battery. Still limited to 240 AH max. Now stop and chop a few trees down. How many 48 volt 1 to 80 AH batteries have you ever seen or heard of? It would be just plain silly to have a low power 48 volt battery system. If you are operating at 48 volt loads, you are not using 4 toy size 12 volt 20 AH batteries in series to give you any meaningful power. You use 48 volts because you use some serious power, and that demands Amp Hours. No sir in real life if you are running 48 volt batteries you will be using at most 6-Volt batteries with no less than 150 to 200 AH. Who in their right mind is going to build a 48 volt 1 to 80 AH system. Does that clear a few trees?

So yeah it would be nice, but the expense, and what little it buys you just does not add up. All it gains you is charging very small 48 volt batteries. That is an oxymoron. 48 volt is not for small stuff. You can buy 12 volt chargers with adjustable current which has a market. If I put a 2,4,8, 16 amp switch, it will charge any toy size battery from 10 AH up to 200 AH which is in the usable range of all 12 volt battery applications. That is simple, cheap, and marketable. When you move up in battery voltage is for more power, not small 12 volt stuff. You are into 100 AH plus range using 6, 4, and 2 volt batteries.

You want something that you really have no need or use for. That is why you cannot find it.

Now if you want. Right now today you can buy a 12 volt 70 amp charger that you can adjust voltage from 2 to 16 volts, and limit current from 1.5 to 70 amps. It will charge any battery from 2 to 12 volts. Infinitely variable. Nothing automatic, all two knobs with two meters. One to set voltage, and one to set current limit. I have one and 10's of thousands of other Ham Radio operators have them. We just float a 12 volt battery to run our radio equipment. Astron make DC Power Supplies and their VS-XXM series has meters, voltage and current limit adjust. You can have a Astron 70M power supply too for $400. It is the best and toughest CV/CC charger money can buy or dream of. It has a on/off switch and two knobs to turn.

Add a Revletric PL8 to that Astron and know you can charge anything up to 36 volts with 40 amps. Still no 48 volts.

[AzRoute66]

Ugh. Saved your best shot for last. There is iron in your words for all to see.

I'll give you a three pointer on that one, if you will acknowledge that Trojan recommends Boost Charging for bringing batteries out of storage at 3% - 5% of C20. That would encompass very specific settings at all ranges below 30 amps.