LiFe pack monitoring.
03-15-2013, 11:41 PM
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LiFe pack monitoring.
Anyone got a reliable and accurate method of monitoring onboard LiFe battery pack useage?
The advice with the Smart Alarm is that LiFe readings cannot be relied upon to be accurate because of the nature of the flat discharge curve for this cell chemistry.
Rob.
The advice with the Smart Alarm is that LiFe readings cannot be relied upon to be accurate because of the nature of the flat discharge curve for this cell chemistry.
Rob.
03-16-2013, 01:47 AM
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RE: LiFe pack monitoring.
Watching the number of milliamps used from the pack is one way to do it. There is a load tester out there that claims it can be used on A123 and LiFe cell technology.
Electrodynamics came up with an option to check your batteries before flight: http://www.electrodynam.com/rc/EDR-207/index.shtml
Problem with counting milliamps is that it doesn't account for aging cells and reduced capacity of the battery over time. Always charge with a milliamp counting charger so you know how many milliamps were put back in after a series of flights as well. Taking packs below 80% of their capacity on any chemistry is a proven way to give your packs long life and reduce the risk of reaching the "cliff."
Some don't go below 70% on A123 or LiFe batteries, just to be sure.
Electrodynamics came up with an option to check your batteries before flight: http://www.electrodynam.com/rc/EDR-207/index.shtml
Problem with counting milliamps is that it doesn't account for aging cells and reduced capacity of the battery over time. Always charge with a milliamp counting charger so you know how many milliamps were put back in after a series of flights as well. Taking packs below 80% of their capacity on any chemistry is a proven way to give your packs long life and reduce the risk of reaching the "cliff."
Some don't go below 70% on A123 or LiFe batteries, just to be sure.
03-16-2013, 02:00 AM
#4
RE: LiFe pack monitoring.
Formeco used to make the Kodiak switch that measured the amount of milliamps that passed through it whilst switched on, no longer made unfortunately, but there is an Australian company that makes one now, I am not in the UK at the moment so can't get to one to find out the manufacturer, I will have a look when I get back to blighty.
Mike
Mike
03-16-2013, 10:21 AM
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RE: LiFe pack monitoring.
Andy Lo at electrodynam.com makes a calibrated load voltmeter for A123 or LiFe cells....been using it for 2 years.....it is EDR-207 for $39.95 USD.....no fly less than 3.30vunder load....
TA
TA
03-16-2013, 11:37 AM
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RE: LiFe pack monitoring.
ORIGINAL: BaldEagel
Formeco used to make the Kodiak switch that measured the amount of milliamps that passed through it whilst switched on, no longer made unfortunately, but there is an Australian company that makes one now, I am not in the UK at the moment so can't get to one to find out the manufacturer, I will have a look when I get back to blighty.
Mike
Formeco used to make the Kodiak switch that measured the amount of milliamps that passed through it whilst switched on, no longer made unfortunately, but there is an Australian company that makes one now, I am not in the UK at the moment so can't get to one to find out the manufacturer, I will have a look when I get back to blighty.
Mike
Peter
03-16-2013, 02:28 PM
#8
RE: LiFe pack monitoring.
Oz
That's the one's, I have their ignition switch in one of my petrol ships, works as well as the milliamp hour add up switch.
Link to the switch: http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
Mike
That's the one's, I have their ignition switch in one of my petrol ships, works as well as the milliamp hour add up switch.
Link to the switch: http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
Mike
03-16-2013, 08:56 PM
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RE: LiFe pack monitoring.
The packs I use have 2 leads...one with a deans connector, and one with a standard rx connector. I use an on board voltmeter to monitor the voltage hooked up to the rx lead. The deans plugs from both batteries go into a Smart fly Sport Reg
While the discharge curve is somewhat flat, it does decrease and that is easy to monitor. With two batteries sharing the load, it will not take a catastrophic dive in voltage without some warning. The pilot obviously has the responsibility to check the voltages before and after the flight - that is part of our pre- and post-flight routine.....
Anyways, that is what works for us....
While the discharge curve is somewhat flat, it does decrease and that is easy to monitor. With two batteries sharing the load, it will not take a catastrophic dive in voltage without some warning. The pilot obviously has the responsibility to check the voltages before and after the flight - that is part of our pre- and post-flight routine.....
Anyways, that is what works for us....
03-16-2013, 11:49 PM
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RE: LiFe pack monitoring.
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
03-17-2013, 01:14 AM
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RE: LiFe pack monitoring.
Thanks gents some great suggestions, I particularly like the look of the Booma RC stuff from down under so I think I will be putting an order in.
Rob.
Rob.
03-17-2013, 04:46 AM
#12
RE: LiFe pack monitoring.
ORIGINAL: JohnMac
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
Is the BIC a truly redundant switch? I know it uses two battery inputs, but are there two totally isolated outputs? In other words, could a single circuit failure of the BIC switch kill the battery supply of both batteries simultaneously. Can't seem to find this info.
I notice that the Boomarc Intelliswitch V2 shows it to have 2 x independent high powered digital
switching circuits.
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
03-17-2013, 08:59 AM
#13
RE: LiFe pack monitoring.
Been using the Boomer switch's for about a year now without incident, prior to this I used the Fromeco Kodiak switch again without incident, useful to know how many milli amps used during each flight, prior to this I used bog standard heavy duty Futaba radio switches and just measure how many milli amps I put back in to my batteries from my charger, if I flew more than four times I did a quick charge on site, why do I have to make everything more complicated? is it just a bling thing, or do I need all this information on site? In retrospect I don't think I do, but this will not stop me using these switches and noting down all the information in my flight log to poor over later and analysis in minutia.
Mike
Mike
03-17-2013, 10:38 AM
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RE: LiFe pack monitoring.
ORIGINAL: BaldEagel
Been using the Boomer switch's for about a year now without incident, prior to this I used the Fromeco Kodiak switch again without incident, useful to know how many milli amps used during each flight, prior to this I used bog standard heavy duty Futaba radio switches and just measure how many milli amps I put back in to my batteries from my charger, if I flew more than four times I did a quick charge on site, why do I have to make everything more complicated? is it just a bling thing, or do I need all this information on site? In retrospect I don't think I do, but this will not stop me using these switches and noting down all the information in my flight log to poor over later and analysis in minutia.
Mike
Been using the Boomer switch's for about a year now without incident, prior to this I used the Fromeco Kodiak switch again without incident, useful to know how many milli amps used during each flight, prior to this I used bog standard heavy duty Futaba radio switches and just measure how many milli amps I put back in to my batteries from my charger, if I flew more than four times I did a quick charge on site, why do I have to make everything more complicated? is it just a bling thing, or do I need all this information on site? In retrospect I don't think I do, but this will not stop me using these switches and noting down all the information in my flight log to poor over later and analysis in minutia.
Mike
Rob.
03-17-2013, 12:48 PM
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RE: LiFe pack monitoring.
ORIGINAL: Countryboy
John,
Is the BIC a truly redundant switch? I know it uses two battery inputs, but are there two totally isolated outputs? In other words, could a single circuit failure of the BIC switch kill the battery supply of both batteries simultaneously. Can't seem to find this info.
I notice that the Boomarc Intelliswitch V2 shows it to have 2 x independent high powered digital
switching circuits.
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
ORIGINAL: JohnMac
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
Is the BIC a truly redundant switch? I know it uses two battery inputs, but are there two totally isolated outputs? In other words, could a single circuit failure of the BIC switch kill the battery supply of both batteries simultaneously. Can't seem to find this info.
I notice that the Boomarc Intelliswitch V2 shows it to have 2 x independent high powered digital
switching circuits.
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
John
04-05-2013, 04:46 AM
#16
RE: LiFe pack monitoring.
ORIGINAL: Countryboy
John,
Is the BIC a truly redundant switch? I know it uses two battery inputs, but are there two totally isolated outputs? In other words, could a single circuit failure of the BIC switch kill the battery supply of both batteries simultaneously. Can't seem to find this info.
I notice that the Boomarc Intelliswitch V2 shows it to have 2 x independent high powered digital
switching circuits.
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
ORIGINAL: JohnMac
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
Hi Rob,
You may have noticed that I run Emcotec BIC swithes in my jets. I only use a123 batteries. Before each flight as I do my general checks i waggle all the servos at the same time whilst watching the voltage screen for each battery.If I see much deviation from 6.6V I recharge. It is rare for me to see them drop to 6.5v TBH, in any normal days flying.
John
Is the BIC a truly redundant switch? I know it uses two battery inputs, but are there two totally isolated outputs? In other words, could a single circuit failure of the BIC switch kill the battery supply of both batteries simultaneously. Can't seem to find this info.
I notice that the Boomarc Intelliswitch V2 shows it to have 2 x independent high powered digital
switching circuits.
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1
Note that I have been using the BIC and BIC V2 for years and never saw any failure of this product.
http://www.ultimate-jets.net/collect...ec-accessories
04-05-2013, 06:28 AM
#17
RE: LiFe pack monitoring.
I keep it pretty simple with all my system critical batteries where any sort of voltage fluctuation under load may mean a flame out or a brown out.
I do a series of "observation" charges and discharges when I get the packs new. I just did a few over the last couple days with new packs. This more than anything tests the capacity I have in each pack and I do this with my smart chargers that balance individual cells and also measure capacity in and out and can do a charge and discharge while balancing. I'll set a base line for capacity and cell voltages. I'll make a label tag and stick it on the pack with the cell voltages at max charge and the capacity I see plus the date I started using the pack - or just write it on the pack with a sharpie. The volts and capacity will vary over time, as the cells age and be a good way to know when to get new ones. Beginning of the season I do it and the end of the season I'll do it and replace/over stick the label so I know.
Fly the jet, note how many Mah after each flight if it's a new jet. Then stretch the flights to two, three, etc. On my packs I typically limit the flights to never take more than 50 percent off the packs since usually I fly slightly over sized packs and can fly several flights this way. It keeps the flight count down to a reasonable level where I'm never gonna forget how many flights I've had. And at 50 percent, a pack can be field topped off in 10 to 15 minutes while I take on a conversation or two and have a coke break.
I do a series of "observation" charges and discharges when I get the packs new. I just did a few over the last couple days with new packs. This more than anything tests the capacity I have in each pack and I do this with my smart chargers that balance individual cells and also measure capacity in and out and can do a charge and discharge while balancing. I'll set a base line for capacity and cell voltages. I'll make a label tag and stick it on the pack with the cell voltages at max charge and the capacity I see plus the date I started using the pack - or just write it on the pack with a sharpie. The volts and capacity will vary over time, as the cells age and be a good way to know when to get new ones. Beginning of the season I do it and the end of the season I'll do it and replace/over stick the label so I know.
Fly the jet, note how many Mah after each flight if it's a new jet. Then stretch the flights to two, three, etc. On my packs I typically limit the flights to never take more than 50 percent off the packs since usually I fly slightly over sized packs and can fly several flights this way. It keeps the flight count down to a reasonable level where I'm never gonna forget how many flights I've had. And at 50 percent, a pack can be field topped off in 10 to 15 minutes while I take on a conversation or two and have a coke break.
04-05-2013, 06:33 AM
#18
RE: LiFe pack monitoring.
ORIGINAL: Eddie P
I keep it pretty simple with all my system critical batteries where any sort of voltage fluctuation under load may mean a flame out or a brown out.
I do a series of ''observation'' charges and discharges when I get the packs new. I just did a few over the last couple days with new packs. This more than anything tests the capacity I have in each pack and I do this with my smart chargers that balance individual cells and also measure capacity in and out and can do a charge and discharge while balancing. I'll set a base line for capacity and cell voltages. I'll make a label tag and stick it on the pack with the cell voltages at max charge and the capacity I see plus the date I started using the pack - or just write it on the pack with a sharpie. The volts and capacity will vary over time, as the cells age and be a good way to know when to get new ones. Beginning of the season I do it and the end of the season I'll do it and replace/over stick the label so I know.
Fly the jet, note how many Mah after each flight if it's a new jet. Then stretch the flights to two, three, etc. On my packs I typically limit the flights to never take more than 50 percent off the packs since usually I fly slightly over sized packs and can fly several flights this way. It keeps the flight count down to a reasonable level where I'm never gonna forget how many flights I've had. And at 50 percent, a pack can be field topped off in 10 to 15 minutes while I take on a conversation or two and have a coke break.
I keep it pretty simple with all my system critical batteries where any sort of voltage fluctuation under load may mean a flame out or a brown out.
I do a series of ''observation'' charges and discharges when I get the packs new. I just did a few over the last couple days with new packs. This more than anything tests the capacity I have in each pack and I do this with my smart chargers that balance individual cells and also measure capacity in and out and can do a charge and discharge while balancing. I'll set a base line for capacity and cell voltages. I'll make a label tag and stick it on the pack with the cell voltages at max charge and the capacity I see plus the date I started using the pack - or just write it on the pack with a sharpie. The volts and capacity will vary over time, as the cells age and be a good way to know when to get new ones. Beginning of the season I do it and the end of the season I'll do it and replace/over stick the label so I know.
Fly the jet, note how many Mah after each flight if it's a new jet. Then stretch the flights to two, three, etc. On my packs I typically limit the flights to never take more than 50 percent off the packs since usually I fly slightly over sized packs and can fly several flights this way. It keeps the flight count down to a reasonable level where I'm never gonna forget how many flights I've had. And at 50 percent, a pack can be field topped off in 10 to 15 minutes while I take on a conversation or two and have a coke break.
04-05-2013, 07:46 AM
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RE: LiFe pack monitoring.
Have a look at the PowerBox Base Log. It works with both batteries and will give you the amount of capacity in mah remaining and voltage remaining flight after flight until you reset it. Here is the link.
https://duraliteflightsystems.com/in...-from-powerbox
https://duraliteflightsystems.com/in...-from-powerbox
04-05-2013, 09:18 AM
#20
RE: LiFe pack monitoring.
I agree with Eddies approach, and that is what I do with my Lithium Ions.
I think that the idea of LiFe is to eliminate regulators. So, if you start adding things (fancy switches, counters, whatever) you defeat the purpose of going Life. You might as well stick to Lions or lipos which are much lighter
Just my 2cents
I think that the idea of LiFe is to eliminate regulators. So, if you start adding things (fancy switches, counters, whatever) you defeat the purpose of going Life. You might as well stick to Lions or lipos which are much lighter
Just my 2cents
04-05-2013, 10:07 AM
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RE: LiFe pack monitoring.
I dont use LiFe to eliminate regulators because they are still well above the recommended max voltage for a lot of servos, don't ask me how I know [
] I think they are also safer and able to take more abuse than LiPo's.
Rob.
] I think they are also safer and able to take more abuse than LiPo's.Rob.
04-05-2013, 10:33 AM
#22
RE: LiFe pack monitoring.
Personally, if I will still use regulators, I rather use Lions for weight reasons. They can also take a lot of abuse.
The only drawback is that the charging time is slower on Lions
Maybe you can use one of those little line regulators for the specific servo that doesnt take 6.6? those are cheap, and if they fail, it is only that servo what you will lose.
just a thought...
The only drawback is that the charging time is slower on Lions
Maybe you can use one of those little line regulators for the specific servo that doesnt take 6.6? those are cheap, and if they fail, it is only that servo what you will lose.
just a thought...
04-06-2013, 07:06 AM
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RE: LiFe pack monitoring.
I just purchased 2 of Fromeco's A123 packs a Wolverine Switch and a Cricket. The Cricket records the lowest voltage the system sees during a flight; it uses a graduated radial LED light ring to monitor the system voltage. It appears to be a nice little setup.
http://www.fromeco.org/Products/05RCCRIK/
http://www.fromeco.org/Products/05RCCRIK/
