Charger for top balance

[Rossman]

At some point in the not too distant future my cells will arrive from China and I will need to top balance them before putting them into service.

Which is a better charger (price not a factor):

Hammatek 30V 10A benchtop charger (from amazon.ca, which doesn't have all the dr. meter supplies amazon.com has)
or
iCharger X8 (or other icharger)

Thoughts?

 

[time2roll]

The Hammatek is probably fine for the classic parallel balance. Although I like the idea of the hobby charger that connects and balances each cell independently. I have not used one of these... just seen a few posts. Need to feed it with DC is the only issue as it may require a power supply for that.

 

[Bud Martin]

BTW, get some 10ga wire and ringlugs too since the cables and the clips that come with the power supply are not good enough for the job.

 

[MisterSandals]

Although I like the idea of the hobby charger that connects and balances each cell independently. I have not used one of these... just seen a few posts. Need to feed it with DC is the only issue as it may require a power supply for that

I use a hobby charger for top balancing. I have enough cells to make a couple 12V batteries. I charge 1 12V battery with solar and then disassemble it to all parallel. Then i charge the 2nd 12V battery with solar and while doing this, use it as a power source for the hobby charger to top balance "battery 1" all in parallel. I then repeat the process for parallel top balancing battery 2 (put in parallel). Works great.

I do not own a grid powered bench top charger.

 

[Rossman]

The reason I liked the iCharger is because it can charge at higher than 10A. (30A or 40A depending on model). As I will have 64 280Ah cells I dont want it to take a wild amount of time to commission them

 

[Just John]

The reason I liked the iCharger is because it can charge at higher than 10A. (30A or 40A depending on model). As I will have 64 280Ah cells I dont want it to take a wild amount of time to commission them

The icharger is nice, but what are you using to power the charger?

 

[Horsefly]

Early on I tried using a hobby charger (iSDT Q8) to top balance my first set of cells. I discovered that this particular charger would get cells up to the set voltage and then immediately stop. It may not be a big deal, but for top balancing I prefer to hold the top voltage until the current has dropped off to nearly nothing. There didn't seem any way to get the hobby charger - or at least this hobby charger - to do that.

As others have pointed out, in order to have the hobby charger do the charging you need a power supply into it. Seems like you might as well just have the power supply set to 3.65V and do the top balance with it.

 

[Rossman]

The icharger is nice, but what are you using to power the charger?

A power supply?

Seems like you might as well just have the power supply set to 3.65V and do the top balance with it.

The power supply doesn't output the correct voltage

 

[Horsefly]

Hammatek 30V 10A benchtop charger

Isn't this the one you were talking about?

 

[Rossman]

Isn't this the one you were talking about?

I mean.....yes? But I think you misunderstood my question. It was about two potential options for top balancing:

Option 1) Hammatek 10A benchtop power supply (max 10amps output for charging)

Option 2) Power supply (unrelated to option 1) -> iCharger X8 (max 30amps output for charging)

 

[Just John]

Option 2) Power supply (unrelated to option 1) -> iCharger X8 (max 30amps output for charging)

What power supply do you use for a 30 amp output?
In other words, iCharger for $99 + "what"?

 

[Rossman]

What power supply do you use for a 30 amp output?
In other words, iCharger for $99 + "what"?

30A @ 3.6V is only about a hundred watts. I've got a few old DC power supplies that would do the job, why?

 

[Horsefly]

Using your iCharger is probably fine, but I would opt for a bench power supply, set it to 3.65V, connect to all the cells in parallel, and be patient.

The iCharger may actually take longer anyway. It will try and charge the pack, and will attempt to passively balance the cells that get up above the 3.65V set-point, or at least my iSDT Q8 did. Once the first cell got to 3.65V it took forever for the others to catch up.

Putting all the cells in parallel and doing a top-balance takes the unknown "smarts" of the iCharger out of the equation.

 

[WindWizard]

I prefer to use my time other than top balancing cells. I just connect them up with a BMS. Connect the panels to the charge controller and the charge controller to the Cells and then let them do their thing. Once one of the Cells starts to go into imbalance, then I connect an automotive light and take it down to the lowest Cell in the group. It works great and does not require a great deal of time and you do not need to connect all of the Cells in parallel and then remove them all. You just connect your system up and use it. No power supply expense. I do use a cheap automotive supply that I hook up to a single Cell to bring that one up if it is really out. Once the Cells get to 3.5V then you need to watch what is going on. It really works very well.

 

[Rossman]

Using your iCharger is probably fine, but I would opt for a bench power supply, set it to 3.65V, connect to all the cells in parallel, and be patient.

The iCharger may actually take longer anyway. It will try and charge the pack, and will attempt to passively balance the cells that get up above the 3.65V set-point, or at least my iSDT Q8 did. Once the first cell got to 3.65V it took forever for the others to catch up.

Putting all the cells in parallel and doing a top-balance takes the unknown "smarts" of the iCharger out of the equation.

The point of using the iCharger is simply to get 30A charging rate - not the balancing features. The batteries would be connected in parallel like you would do with a benchtop supply - just would get to charge at 30A instead of 10A. Seems worthwhile to me to reduce time by a factor of three, especially with 64 cells.

If there were inexpensive benchtop supplies that could charge at higher than 10A, that'd be great, but I have yet to find one.

I prefer to use my time other than top balancing cells. I just connect them up with a BMS. Connect the panels to the charge controller and the charge controller to the Cells and then let them do their thing. Once one of the Cells starts to go into imbalance, then I connect an automotive light and take it down to the lowest Cell in the group. It works great and does not require a great deal of time and you do not need to connect all of the Cells in parallel and then remove them all. You just connect your system up and use it. No power supply expense. I do use a cheap automotive supply that I hook up to a single Cell to bring that one up if it is really out. Once the Cells get to 3.5V then you need to watch what is going on. It really works very well.

I really like this approach, but due to how my equipment room is set up and the size of my packs it would be difficult to do, unfortunately

 

[Just John]

30A @ 3.6V is only about a hundred watts. I've got a few old DC power supplies that would do the job, why?

Because for the iCharger X8, power input is 9v to 49v. Can it be used to do a single cell? Certainly anyone wanting to do more than a single cell at a time (thus justifying spending $99 + "whatever" versus $55) will need more than any old power supply. Especially if you want the 30 amp capability. For about $200 I can get a Riden, much more versatile, although only capable of 24 amps. The Riden will also allow you to set tail current, so is likely to do a much better job when top balancing. I've looked at the iCharger X8, the only reason I didn't get one was the inability to find a suitable power supply. Nice charger, but requires a power supply to be useful, or just buy the power supply.

I've used this:

15 Volt Variable Output Switch Mode 40 Amp DC Power Supply

www.circuitspecialists.com

And really like my Ridens:

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But most people would be better off buying a cheap (~$55) power supply like this:

Amazon.com

Or just add an active balancer and use your solar charge controller:

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I have all of the above, so my question about what 1100 watt power supply you used still stands. I'd like to purchase one and try it out.

 

[RobertGreen]

The way I went about it was to assemble a 16s pack, charge using a mains charger until one of the cells hit the high voltage disconnect limit (I had set it to 3.65)
Then I reconfigured the pack so that all the cells were in parallel and top balanced them using a 30V/10A bench power supply as is commonly shown in top balance tutorials like the one in the resource section of this site. It ended up taking about 12 hours to bring all the cells into top balance.

The next time that I do this, I'm just going to assemble into a 16s pack, charge normally until one cell reaches its limit, then I will connect the lab supply to each cell individually, one by one... Without reconfiguring the pack into parallel! I figure they will take about the same amount of hours to charge this way, but it might be less hassle for me to not have to disassemble/reconfigure the pack twice.

 

[Capt Bill]

I liked the iCharger is because it can charge at higher than 10A. (30A or 40A depending on model).

I am looking for 30 AMP plus CHARGER that can charge a single 3.2v LiFePO4 cell, or set of cells/ and if I am lucky; also charge up to 30 volts for a 24v battery bank. Any web links available for that "iCharger" ... on something similar ??? :+) Bill

 

[Rossman]

I am looking for 30 AMP plus CHARGER that can charge a single 3.2v LiFePO4 cell, or set of cells/ and if I am lucky; also charge up to 30 volts for a 24v battery bank. Any web links available for that "iCharger" ... on something similar ??? :+) Bill

Progressive RC sells the iChargers and a variety of others. As previously mentioned in the thread, if you want an iCharger, you also need to get a power supply that will drive it.

 

[Just John]

I am looking for 30 AMP plus CHARGER that can charge a single 3.2v LiFePO4 cell, or set of cells/ and if I am lucky; also charge up to 30 volts for a 24v battery bank. Any web links available for that "iCharger" ... on something similar ??? :+) Bill

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About $210, but only does 24 amps. Including the 1000-watt power supply.