Lead Acid Battery Facts

[BroMikey]

As charging circuits have evolved it is time to understand what
the newer excepted perimeters are for charging a lead acid battery.


http://www.chargingchargers.com/tutorials/charging.html


Three Stage Battery Charging

[BroMikey]

Battery Testing

Battery Testing

Battery testing can be done in several ways. The most popular
includes measurement of specific gravity, and battery voltage.
Specific gravity applies to wet cells with removable caps, giving access
to the electrolyte. To measure specific gravity, buy a temperature
compensating hydrometer at an auto parts store or tool supply.
To measure voltage, use a digital voltmeter in the DC voltage
setting. The surface charge must be removed from a freshly
charged battery before testing. A 12 hour lapse after charging
qualifies, or you may remove the surface charge with a load (20
amps for 3 plus minutes).


State of Charge Voltage Specific Gravity


12V 6V
100% 12.7 6.3 1.265
75% 12.4 6.2 1.225
50% 12.2 6.1 1.190
25% 12.0 6.0 1.155
Discharged 11.9 6.0 1.120




Load testing is another method of testing a battery. Load testing
removes amps from a battery (similar to starting an engine). Some
battery companies label their battery with the amp load for testing.
This number is usually 1/2 of the CCA rating. For instance, a 500
CCA battery would load test at 250 amps for 15 seconds. A load
test can only be performed if the battery is at or near a full charge.
Some electronic load testers apply a 100 amp load for 10 seconds,
and then display battery voltage. This number is compared to a
chart on the tester, based on CCA rating to determine battery
condition.

Sulphation of batteries starts when specific gravity falls below
1.225 or voltage measures less than 12.4 (12v Battery ) or 6.2
(6 volt battery). Sulphation can harden on the battery plates if
left long enough, reducing and eventually destroying the ability of
the battery to generate rated volts and amps. There are devices for
removing hard sulphation, but the best practice is preventing
formation by proper battery care and recharging after a discharge
cycle. Sulphation is the main reason a significant portion of lead
acid batteries don't attain their chemical life span.

[RAMSET]

a very useful resource for beginners and professionals

many of the fellows use this resource

Battery Information Table of Contents, Basic to Advanced

[BroMikey]

Scooter Battery Charge Rates

At this site find what a slow charge is for a 5ah battery made with
lead plates.

https://www.electricscooterparts.com/chargingratechart.html

standard rate charger:

12 Volt 1 Amp slow charge

12 Volt 2 Amp fast rate charge


12 Volt 5-8 Ah Pack


However very few sites talk about minimum charging rates because
taking to long to charge is bad for batteries unless you have pulsing
circuits.

The new switchmode charging circuitry is counted in these days and
considered an improvement.