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View Full Version : New "safer" LiPo's + "older" charger?


stanger89
08-25-2005, 05:59 PM
With the ever growing number of "safer" LiPo's out there (Polyquest PCM guard, Kokam BalancePro, etc). I'm beginning to wonder how those are going to work with my Astro 109. I realize they will charge fine "the old way" but is there any way to make use of the balanced charging taps on these new packs and my 109?

I believe the Polyquest's have an "adapter" (PCM Guard) that adapts a normal charger to use the balance taps. Is there anything similar for the BalancePro setup? Would the Polyquest PCM Guard work on a Kokam BalancePro pack (with appropriate plug modification)?

Red Scholefield
08-25-2005, 08:29 PM
With the ever growing number of "safer" LiPo's out there (Polyquest PCM guard, Kokam BalancePro, etc). I'm beginning to wonder how those are going to work with my Astro 109. I realize they will charge fine "the old way" but is there any way to make use of the balanced charging taps on these new packs and my 109?

I believe the Polyquest's have an "adapter" (PCM Guard) that adapts a normal charger to use the balance taps. Is there anything similar for the BalancePro setup? Would the Polyquest PCM Guard work on a Kokam BalancePro pack (with appropriate plug modification)?

It should work with any pack as long as you have the wiring correct. If you make up a connector to get to any one of the cells then your Astro 109 can be used to charge the individual cells when they get out of balance.

The Polyquest PCM Guard just keeps you from charging the pack further if ANY cell reaches 4.2 volts. It does not balance the pack and can leave other cells undercharged until you take the steps to charge them individually.

There will be at least one charge system on the market soon that will actually balance the cells in a pack as long as it has access to all the individual cell interconnections. There are no chargers that can balance a pack without this using only two wire connection.

stanger89
08-26-2005, 03:42 AM
Ooh, thanks for the reply. I had never really looked into how the PCM Guard worked, but suffice to say, that's not what I thought. Is the Kokam BalancePro the system you speak of, or is it something else?

mikenlapaz
08-27-2005, 02:04 AM
but is there any way to make use of the balanced charging taps on these new packs and my 109?


Recently built some Li Ion packs (3S 11.1V) to test some batteries. I ended up using a male 'Molex' (type found attached to PSU) male on the pac. Brought #1 lead to Pos term, #2 to first bat 'link', #3 to second bat 'link', #4 to the lead to Pos terminal.
The female Molex got the sides cut off, used the two center connectors and the wires ended with two banana plugs which fit the charger outlets.

This allows to monitor/ and balance cycle charge each of the 3 cells independantly. The majority of time it can be charged thru the Dean Ultra output plug and #12 wiring.

Carlos
08-27-2005, 02:44 AM
Attached is a pickie of the liPo packs which I have added JST connectors to so I can balance the cells individually but one at a time.
To balance the packs (every 5-10 charges)
Using a Swallow charger, Charge the packs at 1C til the charge rate drops to around 300mA then I disconnect the pack from the charger , reset the charger to 3.7V and charge each cell, via the JST connectors I have added to the cells (ONE AT A TIME) until the cells are charged.
The pack on the left is a TANIC PACK which has Female JST connectors already mounted into the pack.
http://static.rcgroups.com/gallery/data/500/49949100_2347.jpg

OH don't mess with LiPo's as this may happen.
It used to be a 1200mA Etec cell.
http://www.archeli.com.au/cpg133/albums/userpics/10147/normal_lipo%20fire%20comp.jpg

mikenlapaz
08-28-2005, 08:17 AM
Carlos, like the charge routine of doing the bulk of charge into all cells first.

I'm sure there is a story to go with the second pic of the burned case. Think maybe you menant to id it as LiIon .

Carlos
08-28-2005, 12:59 PM
G'Day Mike.
The second photo is/was a LIPo cell.
The story.
The + tag on the cell had broken off rendering the cell usless. I figured I would dispose of the cell.
I rembered the kokam instructions saying place a cut in the LiPo outer wraping and place the cell in salt water. But what I didn't remember was to DISCHARGE the cell first. No damage to anything as I was quick enough to through the cell outside the shed when it started hissing. Don't think I will be putting LiPo's in any of my fuel helis to power the rec after seeing that cell go up in smoke.

Reddog
09-11-2005, 07:52 PM
Red, I was told a while back that topping off a LiPo, that had been setting a while, would damage it. I use a Triton. Is there any truth to that? Dick

Azarr
09-11-2005, 10:42 PM
Astro Bob is working on a balancer as an add on for the 109 and supposedly will have adaptors available to fit the many different connectors being used by the pack manufacturers.

I would expect to see them at the NEAT Fair next week, since Bob will be there.

Azarr
www.ecubedrc.com (http://www.ecubedrc.com)

Red Scholefield
09-11-2005, 11:13 PM
Red, I was told a while back that topping off a LiPo, that had been setting a while, would damage it. I use a Triton. Is there any truth to that? Dick

It amazes me that their are so many Lithium experts when we have only had the technolgy for a few years.:cool: If the voltage limit is where it is suppose to be I don't see how you could damage a pack by topping it off if the voltage has dropped a bit. "Setting a while" could be several weeks or months. If it has only be setting for a day or so then topping off wouldn't be necessary anyway.

Red Scholefield
09-11-2005, 11:17 PM
Astro Bob is working on a balancer as an add on for the 109 and supposedly will have adaptors available to fit the many different connectors being used by the pack manufacturers.

I would expect to see them at the NEAT Fair next week, since Bob will be there.

Azarr
www.ecubedrc.com (http://www.ecubedrc.com)

Looks like their are going to be a lot of options for balancing presented to the hobby. FMA Skyvolt system looks good for larger applications. I like the viewer you can download to show the progress, how much charge input and status of the individual cells.

One thing, don't let anyone tell you they have a balancing charger if there are not provisions for addressing each cell individually. Lots of us have been adding our own taps so we can measure each cell and charge individually if they appear out of balance.

Reddog
09-12-2005, 12:42 AM
It amazes me that their are so many Lithium experts when we have only had the technolgy for a few years.:cool: If the voltage limit is where it is suppose to be I don't see how you could damage a pack by topping it off if the voltage has dropped a bit. "Setting a while" could be several weeks or months. If it has only be setting for a day or so then topping off wouldn't be necessary anyway.

Thanks, Red!
That's what I thought!
Dick

Azarr
09-12-2005, 01:57 AM
Looks like their are going to be a lot of options for balancing presented to the hobby. FMA Skyvolt system looks good for larger applications. I like the viewer you can download to show the progress, how much charge input and status of the individual cells.

One thing, don't let anyone tell you they have a balancing charger if there are not provisions for addressing each cell individually. Lots of us have been adding our own taps so we can measure each cell and charge individually if they appear out of balance.

Which is one of the reasons I've been using the Tanic's for a while now. With most manufacturer's jumping on the bandwagon I wouldn't buy a pack without taps unless it was a very small pack for indoor where weight may be a concern.

Fred Marks was showing his system at the Pyramid in Memphis in April and it looks outstanding, glad to see them hitting the market.

Azarr
www.ecubedrc.com (http://www.ecubedrc.com)