Lead Acid puzzle

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.

On Tue, 01 Sep 2020 00:31:18 +0100, Chris <xxx.syseng.yyy@gfsys.co.uk>
wrote:

>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

I think it may be the same here.  I also seem to remember Nickel Iron
batteries were used because of their very long life however they
needed to have their electrolyte changed out every so often.

Not sure about Gels but I seem t remember them as well were used.

In either case, long easy life in Float for CO batteries.

Now, AGMs are newer.  AGMs plump when you cook 'em !

Batrery balancing is a good thing even for lead acid if you can get
it, especially on a 2V cell basis but 6V at a whack is OK too.

boB

On Tuesday, 1 September 2020 00:31:43 UTC+1, Flyguy  wrote:
> 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.

I see you're right, it says 

" 3 Knobs means different charging voltage : Low Medium, High
For axample, Charging 12V Battery, "Low" knob voltage between 13.8V to 14.2V, "Medium" voltage between 14.2V to 14.8V , "High"knob voltage above 15V , "

But 13.8 - 14.2v is too high for AGM. The present 13.7v charger is overcooking them. I wonder if the beeleb is moddable. But still no temp comp :/ $255 inc delivery is a bit steep too, and no clue if it'll run on 240v either. Too many issues.


NT