You understand that the row labeled "Charger Voltage Setting" is not the
actual voltage coming out of the charger, but the knob position or
setting that you would see printed on the faceplate of the charger.
(See note #3 directly under table 3.) The actual voltage that comes out
of the charger when you set it to "12v" is either 13.8-14.4 volts if the
"charge" indicator is on, or 13.5 volts if the "float" indicator is lit.
The very lowest charge voltage listed for a "12 volt" battery is 13.2
volts. A 12v battery simply won't charge fully with less voltage. This
is the very definition of the "float" voltage. It is the _minimum_
voltage needed to _maintain_ a lead acid battery at 100% charge. Below
the float voltage, the battery will never charge fully. At 12.9 volts,
it likely would not charge very much, if at all.
This assumes of course that the battery is at 25 Celsius, of course. You
would need a higher voltage at lower temperature and a lower voltage at
higher temperature.
Batteries are very very complicated chemical beasts. They are not ideal
electrical devices, and don't follow simple rules like most electrical
components.
If you want to learn a little about batteries, I would suggest that you
start by reading:
Battery Reference Book, by T. R. Crompton
http://survival-training.info/Library/Batteries/Battery%20Reference%20Book%203rd%20ed%20-%20T.%20Crompton.pdf
and
Rechargeable Batteries Application Handbook, by Gates Energy
http://www.amazon.com/Rechargeable-Batteries-Applications-Handbook-Engineers/dp/0750670061
For the small investment of ~$40 or so, and a number of evening's time,
you can gain a decent basic knowledge of rechargeable battery
technology. Not at all a light read, I'm afraid.
Bill Dube'
On 1/12/2016 7:22 PM, dovepa via EV wrote:
Besides Bill, I can read too!
Take a look at table 3.
Point was I don't need Lee's opinion or yours or anyone else's this sort of
information is provided by the manufacturer.
Sent from my Verizon Wireless 4G LTE smartphone-------- Original message --------From: Bill
Dube via EV <[email protected]> Date: 1/12/2016 6:17 PM (GMT-06:00) To: Electric
Vehicle Discussion List <[email protected]> Subject: Re: [EVDL] Lead battery charging
to 13.2v
You say 2.15 volts per cell. That is 2.15 x 6 = 12.9 volts for a "12
volt" lead acid battery. That is the _incorrect_ voltage for charging a
12 volt battery. The battery would never reach 100% charge at that voltage.
You would want to charge to at least the "float" voltage of 13.2 volts.
The battery would eventually reach full charge at the float voltage. It
might take a long time, but it would get there.
According to the Trojan battery reference (that _you_ gave,) you have a
choice of a float voltage of 13.2 volts, or a "daily charge" of 14.8
volts, or an "equalize charge" of 15.5 volts.
The Trojan page you referenced is specific to _flooded_ lead acid
batteries however, rather than the sealed lead acid battery, either AGM
or perhaps "Gell Cell", that the fellow was originally asking advice
about. If that is indeed the fact (likely not, as a "gell cell" is
typically really a VRLA AGM these days,) then something between 13.2 to
14.4 would be the appropriate voltage, just as Lee Hart's battery page
says.
A real gell cell would foam the gelled electrolyte if you gave it an
"equalize" charge listed on the Trojan battery page, and that would be
the end of it.
Bill Dube'
On 1/12/2016 11:49 AM, dovepa via EV wrote:
There are things you can do to maximize life of the cells and the
manufactures have recommended voltage and current settings but they will charge
all the way up with anything above 2.15 volts.
I prefer to go to manufactures recommendations myself.
http://www.trojanbattery.com/tech-support/battery-maintenance/
Sent from my Verizon Wireless 4G LTE smartphone-------- Original message --------From: Bill
Dube via EV <[email protected]> Date: 1/12/2016 12:35 PM (GMT-06:00) To: Electric
Vehicle Discussion List <[email protected]> Subject: Re: [EVDL] Lead battery charging
to 13.2v
Paul,
It is not so simple.
As David suggests, it is best to read Lee Hart's battery charging basics:
http://www.evdl.org/pages/hartcharge.html
There is a _lot_ more to charging batteries than
you might think. Even Lee's "brief" tutorial
leaves quite a few of the subtleties out.
Bill D.
At 10:37 AM 1/12/2016, you wrote:
Lead acid cell voltage is 2.15 volts. 6 cells
make 12.9 volts. Anything above 12.9 will charge
it fully. Sent from my Verizon Wireless 4G LTE
smartphone-------- Original message
--------From: Robert Bruninga via EV
<[email protected]> Date: 1/12/2016 9:07
AM (GMT-06:00) To: Electric Vehicle Discussion
List <[email protected]> Subject: [EVDL] Lead
battery charging to 13.2v I put a gel cell on a
benchtop power supply and it charged overnight
to zero current at about 13.2v. So I upped it
to 13.8 to finish the charge and it basically
would not take cany more current. I always
thought the 13.8 and even 14v was the float
voltage and you had to at least get to that
voltage. I also remember that something like
13.2 is the highest one should go to provent any
gassing
Anyway, if one leaves a battery
overnight on 13.2v and it tapers to 0, is it
âfullâ. If so, what is 13.8 all
aboiut. Bob -------------- next part
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