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In article <d95655fb-7655-4156-a1b7-44ae2f89379co@googlegroups.com>,
Tabby <tabbypurr> wrote:
On Friday, 28 August 2020 19:50:55 UTC+1, Chris wrote:
On 08/27/20 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after
fitting new batteries the available range is down to below 10%. I\'m not
clear what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v
output. Single stage charging only. It has always been promptly charged
after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6& 13.8v.
Charged each battery independantly to 15.2v, which took maybe half an
hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v& 12.8v. I
expected to see lower.
What\'s going on here?
NT
The data sheets for the better brands of the gel cell types have
a graph showing expected life vs number of charge / recharge
cycles. Typical design life for ups float applications can be as much
as 10 years, but under regular cycling, can be << 5 years.
The deeper the discharge, the more detrimental the effect.
Carts must hammer batteries pretty hard, especially if they skimp on
a/h capacity to keep costs down. 38ah doesn\'t sound like much for
what must be a 1/2 to 1hp motor, at 24 v, 1hp ~= 30 amp, then you
have the much higher startup current. You get what you pay for, but
Yuasa at least have different optimised types depending on type of
service.
I would put in bigger batteries, say 100 ah might work a lot better...
Chris
2x 100Ah adds a ton of weight. Range is not a problem, depth of
discharge is usually fine, just occasionally pushed. Looks like it
mainly needs a reasonably decent charger.
Where did I get the idea that car batteries, golf cart batteries
and marine boat batteries all have fundamentally different designs?
Where did I hear that golf cart batteries can be routinely discharged
to about 10.5 volt, which would kill a car battery?
At least you should not head any generic advice about handling
batteries, i.e. advise that doesnot address the specific battery you have.
You may assume that golf cart batteries are okay for golf carts.
1hp? Dunno but I doubt it. The onboard breaker is 30A.
NT
Groetjes Albert
On Friday, 28 August 2020 01:30:59 UTC+1, Flyguy wrote:
On Thursday, August 27, 2020 at 4:51:35 AM UTC-7, Martin Brown wrote:
On 27/08/2020 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I\'m not clear what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6 & 13.8v. Charged each battery independantly to 15.2v, which took maybe half an hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v & 12.8v. I expected to see lower.
What\'s going on here?
Battery abuse. The cheap charger has knackered both of your batteries.
Recharging lead acid cells for maximum longevity requires some form of
thermal compensation of the voltage per cell during charging. eg
https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
Too much over voltage and they gas. Incorrect treatment on top up and
they sulphate or corrode internally either way you do damage to them.
The weakest cell in a chain fails first and the others then wreck it.
--
Regards,
Martin Brown
Temperature compensation during charging is vital to maintaining the health of a battery, and they are available:
http://www.chargingchargers.com/chargers/golf-cart/48-volt-yamaha-18.html
You must have a REALLY old cart, being 24V.
It\'s 48v, 115v and $459, no use on 3 counts. The ones nearer what I\'m looking for lack temp compensation.
NT
On Friday, August 28, 2020 at 7:23:27 PM UTC-7, Tabby wrote:
On Friday, 28 August 2020 01:30:59 UTC+1, Flyguy wrote:
On Thursday, August 27, 2020 at 4:51:35 AM UTC-7, Martin Brown wrote:
On 27/08/2020 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I\'m not clear what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6 & 13.8v. Charged each battery independantly to 15.2v, which took maybe half an hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v & 12.8v. I expected to see lower.
What\'s going on here?
Battery abuse. The cheap charger has knackered both of your batteries.
Recharging lead acid cells for maximum longevity requires some form of
thermal compensation of the voltage per cell during charging. eg
https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
Too much over voltage and they gas. Incorrect treatment on top up and
they sulphate or corrode internally either way you do damage to them.
The weakest cell in a chain fails first and the others then wreck it.
--
Regards,
Martin Brown
Temperature compensation during charging is vital to maintaining the health of a battery, and they are available:
http://www.chargingchargers.com/chargers/golf-cart/48-volt-yamaha-18.html
You must have a REALLY old cart, being 24V.
It\'s 48v, 115v and $459, no use on 3 counts. The ones nearer what I\'m looking for lack temp compensation.
NT
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
On Saturday, 29 August 2020 18:30:03 UTC+1, Flyguy wrote:
On Friday, August 28, 2020 at 7:23:27 PM UTC-7, Tabby wrote:
On Friday, 28 August 2020 01:30:59 UTC+1, Flyguy wrote:
On Thursday, August 27, 2020 at 4:51:35 AM UTC-7, Martin Brown wrote:
On 27/08/2020 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I\'m not clear what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6 & 13.8v. Charged each battery independantly to 15.2v, which took maybe half an hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v & 12.8v. I expected to see lower.
What\'s going on here?
Battery abuse. The cheap charger has knackered both of your batteries.
Recharging lead acid cells for maximum longevity requires some form of
thermal compensation of the voltage per cell during charging. eg
https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
Too much over voltage and they gas. Incorrect treatment on top up and
they sulphate or corrode internally either way you do damage to them.
The weakest cell in a chain fails first and the others then wreck it.
--
Regards,
Martin Brown
Temperature compensation during charging is vital to maintaining the health of a battery, and they are available:
http://www.chargingchargers.com/chargers/golf-cart/48-volt-yamaha-18.html
You must have a REALLY old cart, being 24V.
It\'s 48v, 115v and $459, no use on 3 counts. The ones nearer what I\'m looking for lack temp compensation.
NT
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
Of course there are. On that page:
1. no V_out data, no temp comp, 110v only
2. adpow: too high V_out for flooded cells
3. $668
4. noco: no 24v AGM mode, no temp comp
5. topac: no V_out data, no temp comp
6. V_out too high & not temp comp
7. noco: $229
8. beeleb: no V_out data, claims unsuited to <40Ah.
9. AIMS: $229
10. Genie $292
11. promariner: no V_out data, no temp comp
12. 6/12v only
13. same as 1
14. Promariner: all charge options too high V_out & well north of $200.
15. Promariner: no data
16. Beeleb again
17. LST: no V data, no temp comp
18. Adpow V_out too high, no temp comp, warns that it overcharges
19. V_out too high, no temp comp
20. Beeleb again
21. Renogy: DC input, no temp comp
22. schumacher: not a charger
etc etc etc.
NT
On Saturday, August 29, 2020 at 10:39:31 PM UTC-7, Tabby wrote:
On Saturday, 29 August 2020 18:30:03 UTC+1, Flyguy wrote:
On Friday, August 28, 2020 at 7:23:27 PM UTC-7, Tabby wrote:
On Friday, 28 August 2020 01:30:59 UTC+1, Flyguy wrote:
On Thursday, August 27, 2020 at 4:51:35 AM UTC-7, Martin Brown wrote:
On 27/08/2020 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I\'m not clear what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6 & 13.8v. Charged each battery independantly to 15.2v, which took maybe half an hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v & 12.8v. I expected to see lower.
What\'s going on here?
Battery abuse. The cheap charger has knackered both of your batteries.
Recharging lead acid cells for maximum longevity requires some form of
thermal compensation of the voltage per cell during charging. eg
https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
Too much over voltage and they gas. Incorrect treatment on top up and
they sulphate or corrode internally either way you do damage to them.
The weakest cell in a chain fails first and the others then wreck it.
--
Regards,
Martin Brown
Temperature compensation during charging is vital to maintaining the health of a battery, and they are available:
http://www.chargingchargers.com/chargers/golf-cart/48-volt-yamaha-18.html
You must have a REALLY old cart, being 24V.
It\'s 48v, 115v and $459, no use on 3 counts. The ones nearer what I\'m looking for lack temp compensation.
NT
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
Of course there are. On that page:
1. no V_out data, no temp comp, 110v only
2. adpow: too high V_out for flooded cells
3. $668
4. noco: no 24v AGM mode, no temp comp
5. topac: no V_out data, no temp comp
6. V_out too high & not temp comp
7. noco: $229
8. beeleb: no V_out data, claims unsuited to <40Ah.
9. AIMS: $229
10. Genie $292
11. promariner: no V_out data, no temp comp
12. 6/12v only
13. same as 1
14. Promariner: all charge options too high V_out & well north of $200.
15. Promariner: no data
16. Beeleb again
17. LST: no V data, no temp comp
18. Adpow V_out too high, no temp comp, warns that it overcharges
19. V_out too high, no temp comp
20. Beeleb again
21. Renogy: DC input, no temp comp
22. schumacher: not a charger
etc etc etc.
NT
Not sure what you mean by \"no V_out data\"
On Saturday, 29 August 2020 01:38:09 UTC+1, Chris wrote:
On 08/28/20 23:21, Sjouke Burry wrote:
On 28.08.20 20:50, Chris wrote:
On 08/27/20 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting
new batteries the available range is down to below 10%. I\'m not clear
what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v
output. Single stage charging only. It has always been promptly
charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6& 13.8v.
Charged each battery independantly to 15.2v, which took maybe half an
hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v& 12.8v. I
expected to see lower.
What\'s going on here?
NT
The data sheets for the better brands of the gel cell types have
a graph showing expected life vs number of charge / recharge
cycles. Typical design life for ups float applications can be as much
as 10 years, but under regular cycling, can be<< 5 years.
The deeper the discharge, the more detrimental the effect.
Carts must hammer batteries pretty hard, especially if they skimp on
a/h capacity to keep costs down. 38ah doesn\'t sound like much for
what must be a 1/2 to 1hp motor, at 24 v, 1hp ~= 30 amp, then you
have the much higher startup current. You get what you pay for, but
Yuasa at least have different optimised types depending on type of
service.
I would put in bigger batteries, say 100 ah might work a lot better...
Chris
And dont forget to buy a high quality computerized charger.
A cheap bad one wil sulfide the batteries in notime.
Fully charged terminal voltage is critical as well, typically 2.3
volts per cell max, but the data sheets will have voltage vs
temperature curves. Overcharging increases gassing which should
normally be minimal. The UPS people have years of experience of
that, as opposed to consumer electronics product, where the charger
often looks like an afterthought...
Chris
AIUI gassing is not an option for AGM. That rules out most chargers on offer. UPSes have a terrible record of battery abuse.
I might have to take the idea of making a charger seriously, I\'ve never found one that does what\'s needed. Not that it\'s difficult, 240v 24v multistage AGM charging with temp comp.
NT
On 08/29/20 03:34, Tabby wrote:
On Saturday, 29 August 2020 01:38:09 UTC+1, Chris wrote:
On 08/28/20 23:21, Sjouke Burry wrote:
On 28.08.20 20:50, Chris wrote:
On 08/27/20 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting
new batteries the available range is down to below 10%. I\'m not clear
what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v
output. Single stage charging only. It has always been promptly
charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6&Â 13.8v.
Charged each battery independantly to 15.2v, which took maybe half an
hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v&Â 12.8v. I
expected to see lower.
What\'s going on here?
NT
The data sheets for the better brands of the gel cell types have
a graph showing expected life vs number of charge / recharge
cycles. Typical design life for ups float applications can be as much
as 10 years, but under regular cycling, can be<<Â 5 years.
The deeper the discharge, the more detrimental the effect.
Carts must hammer batteries pretty hard, especially if they skimp on
a/h capacity to keep costs down. 38ah doesn\'t sound like much for
what must be a 1/2 to 1hp motor, at 24 v, 1hp ~= 30 amp, then you
have the much higher startup current. You get what you pay for, but
Yuasa at least have different optimised types depending on type of
service.
I would put in bigger batteries, say 100 ah might work a lot better...
Chris
And dont forget to buy a high quality computerized charger.
A cheap bad one wil sulfide the batteries in notime.
Fully charged terminal voltage is critical as well, typically 2.3
volts per cell max, but the data sheets will have voltage vs
temperature curves. Overcharging increases gassing which should
normally be minimal. The UPS people have years of experience of
that, as opposed to consumer electronics product, where the charger
often looks like an afterthought...
Chris
AIUI gassing is not an option for AGM. That rules out most chargers on
offer. UPSes have a terrible record of battery abuse.
I might have to take the idea of making a charger seriously, I\'ve
never found one that does what\'s needed. Not that it\'s difficult, 240v
24v multistage AGM charging with temp comp.
NT
Float, or end of charge trickle is critical, as is the voltage.
Normally, ups batteries are float charged at a low current
continuously, but one manufacturer has patented the idea of
disconnecting the float charge until the voltage reaches some
lower level, then topping up, rather than a continuous float
charge current. Apparently, it does improve cell lifetimes, but
no direct experience here.
Not too much trouble to build a charger using such ideas,
perhaps with a micro to manage it all, so long as it\'s not
commercial...
Chris
On 2020/08/30 3:57 p.m., Chris wrote:
On 08/29/20 03:34, Tabby wrote:
On Saturday, 29 August 2020 01:38:09 UTC+1, Chris wrote:
On 08/28/20 23:21, Sjouke Burry wrote:
On 28.08.20 20:50, Chris wrote:
On 08/27/20 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after
fitting
new batteries the available range is down to below 10%. I\'m not
clear
what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v
output. Single stage charging only. It has always been promptly
charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6& 13.8v.
Charged each battery independantly to 15.2v, which took maybe
half an
hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v& 12.8v. I
expected to see lower.
What\'s going on here?
NT
The data sheets for the better brands of the gel cell types have
a graph showing expected life vs number of charge / recharge
cycles. Typical design life for ups float applications can be as much
as 10 years, but under regular cycling, can be<< 5 years.
The deeper the discharge, the more detrimental the effect.
Carts must hammer batteries pretty hard, especially if they skimp on
a/h capacity to keep costs down. 38ah doesn\'t sound like much for
what must be a 1/2 to 1hp motor, at 24 v, 1hp ~= 30 amp, then you
have the much higher startup current. You get what you pay for, but
Yuasa at least have different optimised types depending on type of
service.
I would put in bigger batteries, say 100 ah might work a lot
better...
Chris
And dont forget to buy a high quality computerized charger.
A cheap bad one wil sulfide the batteries in notime.
Fully charged terminal voltage is critical as well, typically 2.3
volts per cell max, but the data sheets will have voltage vs
temperature curves. Overcharging increases gassing which should
normally be minimal. The UPS people have years of experience of
that, as opposed to consumer electronics product, where the charger
often looks like an afterthought...
Chris
AIUI gassing is not an option for AGM. That rules out most chargers
on offer. UPSes have a terrible record of battery abuse.
I might have to take the idea of making a charger seriously, I\'ve
never found one that does what\'s needed. Not that it\'s difficult,
240v 24v multistage AGM charging with temp comp.
NT
Float, or end of charge trickle is critical, as is the voltage.
Normally, ups batteries are float charged at a low current
continuously, but one manufacturer has patented the idea of
disconnecting the float charge until the voltage reaches some
lower level, then topping up, rather than a continuous float
charge current. Apparently, it does improve cell lifetimes, but
no direct experience here.
How could that idea be patented? Seems obvious that many battery
charging systems cut the power when they reach a preset voltage, then
energize again when the voltage falls to a certain point. All I can see
them patenting is the particular electronic process, but automobiles
have been using this since alternators and generators first came out to
charge the battery. I am sure the process predates that application too.
Not too much trouble to build a charger using such ideas,
perhaps with a micro to manage it all, so long as it\'s not
commercial...
Chris
John (I have never applied for a patent, and am unlikely ever to want to!)
ALL those chargers provided \"data\" on output - what DON\'T they provide?On Sunday, 30 August 2020 06:54:02 UTC+1, Flyguy wrote:
On Saturday, August 29, 2020 at 10:39:31 PM UTC-7, Tabby wrote:
On Saturday, 29 August 2020 18:30:03 UTC+1, Flyguy wrote:
On Friday, August 28, 2020 at 7:23:27 PM UTC-7, Tabby wrote:
On Friday, 28 August 2020 01:30:59 UTC+1, Flyguy wrote:
On Thursday, August 27, 2020 at 4:51:35 AM UTC-7, Martin Brown wrote:
On 27/08/2020 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I\'m not clear what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6 & 13.8v. Charged each battery independantly to 15.2v, which took maybe half an hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v & 12.8v. I expected to see lower.
What\'s going on here?
Battery abuse. The cheap charger has knackered both of your batteries.
Recharging lead acid cells for maximum longevity requires some form of
thermal compensation of the voltage per cell during charging. eg
https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
Too much over voltage and they gas. Incorrect treatment on top up and
they sulphate or corrode internally either way you do damage to them.
The weakest cell in a chain fails first and the others then wreck it.
--
Regards,
Martin Brown
Temperature compensation during charging is vital to maintaining the health of a battery, and they are available:
http://www.chargingchargers.com/chargers/golf-cart/48-volt-yamaha-18.html
You must have a REALLY old cart, being 24V.
It\'s 48v, 115v and $459, no use on 3 counts. The ones nearer what I\'m looking for lack temp compensation.
NT
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
Of course there are. On that page:
1. no V_out data, no temp comp, 110v only
2. adpow: too high V_out for flooded cells
3. $668
4. noco: no 24v AGM mode, no temp comp
5. topac: no V_out data, no temp comp
6. V_out too high & not temp comp
7. noco: $229
8. beeleb: no V_out data, claims unsuited to <40Ah.
9. AIMS: $229
10. Genie $292
11. promariner: no V_out data, no temp comp
12. 6/12v only
13. same as 1
14. Promariner: all charge options too high V_out & well north of $200.
15. Promariner: no data
16. Beeleb again
17. LST: no V data, no temp comp
18. Adpow V_out too high, no temp comp, warns that it overcharges
19. V_out too high, no temp comp
20. Beeleb again
21. Renogy: DC input, no temp comp
22. schumacher: not a charger
etc etc etc.
NT
Not sure what you mean by \"no V_out data\"
no data on voltage output. Most chargers go too high for SLA. The present charger is causing problems by outputting 2x 13.7v, eveything I\'ve seen on Amazon is worse.
I suspect I\'d need to either build one. I don\'t really want to spend the time though. Or use a bench supply, varying V_out manually between winter & summer.
Beeleb says it is suited for 2 to 200AH.
They probably all are, despite the claims. But not SLA.
NT
On 08/31/20 00:16, John Robertson wrote:
On 2020/08/30 3:57 p.m., Chris wrote:
On 08/29/20 03:34, Tabby wrote:
On Saturday, 29 August 2020 01:38:09 UTC+1, Chris wrote:
On 08/28/20 23:21, Sjouke Burry wrote:
On 28.08.20 20:50, Chris wrote:
On 08/27/20 01:30, Tabby wrote:
Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after
fitting
new batteries the available range is down to below 10%. I\'m not
clear
what\'s gone wrong.
The charger in use has been a cheap chinese one with 2x13.7v=27.4v
output. Single stage charging only. It has always been promptly
charged after use, and never run below 50% charge.
I checked the battery voltages after charge, they were 13.6& 13.8v.
Charged each battery independantly to 15.2v, which took maybe
half an
hour or so. No range improvement.
When apparently flat the batteries read, offload, 12.3v& 12.8v. I
expected to see lower.
What\'s going on here?
NT
The data sheets for the better brands of the gel cell types have
a graph showing expected life vs number of charge / recharge
cycles. Typical design life for ups float applications can be as much
as 10 years, but under regular cycling, can be<< 5 years.
The deeper the discharge, the more detrimental the effect.
Carts must hammer batteries pretty hard, especially if they skimp on
a/h capacity to keep costs down. 38ah doesn\'t sound like much for
what must be a 1/2 to 1hp motor, at 24 v, 1hp ~= 30 amp, then you
have the much higher startup current. You get what you pay for, but
Yuasa at least have different optimised types depending on type of
service.
I would put in bigger batteries, say 100 ah might work a lot
better...
Chris
And dont forget to buy a high quality computerized charger.
A cheap bad one wil sulfide the batteries in notime.
Fully charged terminal voltage is critical as well, typically 2.3
volts per cell max, but the data sheets will have voltage vs
temperature curves. Overcharging increases gassing which should
normally be minimal. The UPS people have years of experience of
that, as opposed to consumer electronics product, where the charger
often looks like an afterthought...
Chris
AIUI gassing is not an option for AGM. That rules out most chargers
on offer. UPSes have a terrible record of battery abuse.
I might have to take the idea of making a charger seriously, I\'ve
never found one that does what\'s needed. Not that it\'s difficult,
240v 24v multistage AGM charging with temp comp.
NT
Float, or end of charge trickle is critical, as is the voltage.
Normally, ups batteries are float charged at a low current
continuously, but one manufacturer has patented the idea of
disconnecting the float charge until the voltage reaches some
lower level, then topping up, rather than a continuous float
charge current. Apparently, it does improve cell lifetimes, but
no direct experience here.
How could that idea be patented? Seems obvious that many battery
charging systems cut the power when they reach a preset voltage, then
energize again when the voltage falls to a certain point. All I can see
them patenting is the particular electronic process, but automobiles
have been using this since alternators and generators first came out to
charge the battery. I am sure the process predates that application too.
Not too much trouble to build a charger using such ideas,
perhaps with a micro to manage it all, so long as it\'s not
commercial...
Chris
John (I have never applied for a patent, and am unlikely ever to want to!)
Chargers for ups systems don\'t cut the power, but keep a small current
float, ma, to make up for losses, whereas the idea is to switch off
the charge completely until the voltage has dropped to a defined lower
level, then re charge to the original end of charge level. Apparently,
this does improve cell life and helps to equalise the individual cell
voltages, a serious problem as battery stacks age. No reference,
sorry, but it may have been APC...
Chris
On Sunday, August 30, 2020 at 12:07:24 AM UTC-7, Tabby wrote:
On Sunday, 30 August 2020 06:54:02 UTC+1, Flyguy wrote:
On Saturday, August 29, 2020 at 10:39:31 PM UTC-7, Tabby wrote:
On Saturday, 29 August 2020 18:30:03 UTC+1, Flyguy wrote:
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
Of course there are. On that page:
1. no V_out data, no temp comp, 110v only
2. adpow: too high V_out for flooded cells
3. $668
4. noco: no 24v AGM mode, no temp comp
5. topac: no V_out data, no temp comp
6. V_out too high & not temp comp
7. noco: $229
8. beeleb: no V_out data, claims unsuited to <40Ah.
9. AIMS: $229
10. Genie $292
11. promariner: no V_out data, no temp comp
12. 6/12v only
13. same as 1
14. Promariner: all charge options too high V_out & well north of $200.
15. Promariner: no data
16. Beeleb again
17. LST: no V data, no temp comp
18. Adpow V_out too high, no temp comp, warns that it overcharges
19. V_out too high, no temp comp
20. Beeleb again
21. Renogy: DC input, no temp comp
22. schumacher: not a charger
etc etc etc.
NT
Not sure what you mean by \"no V_out data\"
no data on voltage output. Most chargers go too high for SLA. The present charger is causing problems by outputting 2x 13.7v, eveything I\'ve seen on Amazon is worse.
I suspect I\'d need to either build one. I don\'t really want to spend the time though. Or use a bench supply, varying V_out manually between winter & summer.
Beeleb says it is suited for 2 to 200AH.
They probably all are, despite the claims. But not SLA.
ALL those chargers provided \"data\" on output
We were doing the Re-Float thing you just described in your last post
at OutBack Power Systems in our inverter/charger almost 20 years ago.
Yes, it supposedly does increase battery life if you don\'t need to
Float all the time. It will draw as much current as necessary to
hold the battery and loads, if any, at that voltage.
I wonder how long ago this patent was ? I haven\'t heard of it being
patented. But since patents are only good for 20 years now in the US,
the prior art would be real close in this case.
boB
On Monday, 31 August 2020 05:20:18 UTC+1, Flyguy wrote:
On Sunday, August 30, 2020 at 12:07:24 AM UTC-7, Tabby wrote:
On Sunday, 30 August 2020 06:54:02 UTC+1, Flyguy wrote:
On Saturday, August 29, 2020 at 10:39:31 PM UTC-7, Tabby wrote:
On Saturday, 29 August 2020 18:30:03 UTC+1, Flyguy wrote:
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
Of course there are. On that page:
1. no V_out data, no temp comp, 110v only
2. adpow: too high V_out for flooded cells
3. $668
4. noco: no 24v AGM mode, no temp comp
5. topac: no V_out data, no temp comp
6. V_out too high & not temp comp
7. noco: $229
8. beeleb: no V_out data, claims unsuited to <40Ah.
9. AIMS: $229
10. Genie $292
11. promariner: no V_out data, no temp comp
12. 6/12v only
13. same as 1
14. Promariner: all charge options too high V_out & well north of $200.
15. Promariner: no data
16. Beeleb again
17. LST: no V data, no temp comp
18. Adpow V_out too high, no temp comp, warns that it overcharges
19. V_out too high, no temp comp
20. Beeleb again
21. Renogy: DC input, no temp comp
22. schumacher: not a charger
etc etc etc.
NT
Not sure what you mean by \"no V_out data\"
no data on voltage output. Most chargers go too high for SLA. The present charger is causing problems by outputting 2x 13.7v, eveything I\'ve seen on Amazon is worse.
I suspect I\'d need to either build one. I don\'t really want to spend the time though. Or use a bench supply, varying V_out manually between winter & summer.
Beeleb says it is suited for 2 to 200AH.
They probably all are, despite the claims. But not SLA.
ALL those chargers provided \"data\" on output
I read the whole ad of every single one on the page. Lots don\'t give V_out data. Those that do all output unsuitable voltage. They\'re designed for flooded cells or only very occasional charge of SLAs.
- what DON\'T they provide?
The list above answered that.
NT
On 08/31/20 07:50, boB wrote:
We were doing the Re-Float thing you just described in your last post
at OutBack Power Systems in our inverter/charger almost 20 years ago.
Yes, it supposedly does increase battery life if you don\'t need to
Float all the time. It will draw as much current as necessary to
hold the battery and loads, if any, at that voltage.
I wonder how long ago this patent was ? I haven\'t heard of it being
patented. But since patents are only good for 20 years now in the US,
the prior art would be real close in this case.
boB
As I said forgot the source, so could have orgiginated much earlier.
Cell balance is a serious issue, in that even with cells from the
same batch, the internal resistance varies with age and with that,
the float voltage, Some cells get undercharged and others over, which
causes gassing and premature failure. One way around that is to fit
each substring, say 12v, with a clamp that bypasses charge current when
the terminal voltage exceeds optimum float value. Float current is
typically 10\'s of mA, so not much dissipation in the shunt.
Telcos probably know more about this than most, with their 50v systems
and BT in the uk at least are big users of gel cel batteries. Some of
their stacks have a separate charger module for each 6 or 12v battery...
Chris
On Monday, August 31, 2020 at 4:06:13 PM UTC-7, Tabby wrote:
On Monday, 31 August 2020 05:20:18 UTC+1, Flyguy wrote:
On Sunday, August 30, 2020 at 12:07:24 AM UTC-7, Tabby wrote:
On Sunday, 30 August 2020 06:54:02 UTC+1, Flyguy wrote:
On Saturday, August 29, 2020 at 10:39:31 PM UTC-7, Tabby wrote:
On Saturday, 29 August 2020 18:30:03 UTC+1, Flyguy wrote:
That was exemplary of a temperature compensated charger - OF COURSE it won\'t work for you. There are plenty of 24V battery chargers out there:
https://www.amazon.com/24-volt-battery-charger/s?k=24+volt+battery+charger
Of course there are. On that page:
1. no V_out data, no temp comp, 110v only
2. adpow: too high V_out for flooded cells
3. $668
4. noco: no 24v AGM mode, no temp comp
5. topac: no V_out data, no temp comp
6. V_out too high & not temp comp
7. noco: $229
8. beeleb: no V_out data, claims unsuited to <40Ah.
9. AIMS: $229
10. Genie $292
11. promariner: no V_out data, no temp comp
12. 6/12v only
13. same as 1
14. Promariner: all charge options too high V_out & well north of $200.
15. Promariner: no data
16. Beeleb again
17. LST: no V data, no temp comp
18. Adpow V_out too high, no temp comp, warns that it overcharges
19. V_out too high, no temp comp
20. Beeleb again
21. Renogy: DC input, no temp comp
22. schumacher: not a charger
etc etc etc.
NT
Not sure what you mean by \"no V_out data\"
no data on voltage output. Most chargers go too high for SLA. The present charger is causing problems by outputting 2x 13.7v, eveything I\'ve seen on Amazon is worse.
I suspect I\'d need to either build one. I don\'t really want to spend the time though. Or use a bench supply, varying V_out manually between winter & summer.
Beeleb says it is suited for 2 to 200AH.
They probably all are, despite the claims. But not SLA.
ALL those chargers provided \"data\" on output
I read the whole ad of every single one on the page. Lots don\'t give V_out data. Those that do all output unsuitable voltage. They\'re designed for flooded cells or only very occasional charge of SLAs.
- what DON\'T they provide?
The list above answered that.
NT
Beeleb does, for one, but you said it doesn\'t.