Can I Charge a Lead Acid Battery With a Lithium Charger
Charging batteries
Charge voltage
Mastervolt gel (two Five, 12 5) and Mastervolt AGM (vi V, 12 Five) batteries should be charged with a voltage of 14.25 Five for 12 V systems and 28.5 5 for 24 V systems. The absorption stage is followed by the float phase (see three-step+ charging characteristic on page 242) in which the voltage is reduced to xiii.8 V for 12 Five systems and 27.half-dozen V for 24 V systems. These figures assume a temperature of 25 °C.
For wet lead-acid batteries, the absorption voltage is 14.25 V for 12 V systems and 28.5 V for 24 V systems. The float voltage for this blazon of battery is 13.25 V for 12 V and 26.5 V for 24 V systems. All of these figures are for 25 °C.
Lithium Ion batteries are charged with an absorption voltage of fourteen.25 V for 12 V, and 28.v 5 for 24 Five systems. The float voltage is 13.5 5 for 12 V and 27 V for 24 V systems.
Charge current
A dominion of thumb for gel and AGM batteries states that the minimum charging current should be 15 to 25 % of the bombardment chapters. During charging, you usually continue to supply power to connected devices, and this power consumption should exist added to the 15-25 %.
This means that a 400 Ah battery bank and a connected load of 10 amperes requires a battery charger chapters of between 70 and 90 amperes in society to charge the bombardment in a reasonable fourth dimension.
The maximum charging electric current is 50 % for a gel battery, and 30 % for an AGM battery. Mastervolt Lithium Ion batteries can be subjected to much higher charge currents. Notwithstanding, to maximise the lifespan of the Lithium Ion bombardment, Mastervolt recommends a maximum charging current of 30 % of the chapters. For a 180 Ah battery, for example, this ways a maximum charge current of lx amperes.
A battery charger with temperature compensation for optimal protection
Ensuring the longest possible lifespan for gel, AGM and Lithium Ion batteries requires a modernistic Mastervolt battery charger with a three-step+ accuse characteristic. These bombardment chargers continuously regulate charge voltage and accuse current.
For moisture gel and AGM batteries, it is recommended to have a sensor for measuring the temperature of the battery. This adjusts the charge voltage to the temperature of the battery, extending its lifespan. We call this 'temperature compensation'.
Temperature compensation curve
Considering devices such as refrigerators are ever cartoon power from a bombardment, fifty-fifty while information technology is being charged, Mastervolt's temperature bounty includes a maximum offsetting effect to protect the connected devices. The bounty is at most 14.55 V for a 12 V system, and 29.1 V for a 24 V organisation.
At very loftier (> fifty °C) and low (<-20 °C) temperatures, moisture gel and AGM batteries may no longer be charged. Exterior of these limits, the Mastervolt battery charger will continue to supply the connected consumers simply not charge the batteries.
Adjusting the voltage to a higher or lower temperature is not required for Lithium Ion batteries.
The formula below is used to calculate the charging time of a Gel or AGM battery:
The formula below is used to calculate the charging time of a Lithium Ion battery:
Lt= charging time
Co= capacity drawn from the battery
eff = efficiency; 1.ane for a Gel battery, i.fifteen for a AGM bombardment and ane.two for a flooded battery
Al = battery charger current
Ab = consumption of the continued equipment during the charging process
Calculating charging time
Calculating the accuse time of a battery should take into business relationship the following:
The first consideration is the efficiency of the battery. In a standard moisture battery, this is around eighty%. This means that if 100 Ah are discharged from the battery, 120 Ah need to be charged in order to be able to extract 100 Ah once again. With gel and AGM batteries, the efficiency is higher – 85 to ninety % – then there is less loss and the charge time is shorter in comparing with wet batteries. In Lithium Ion batteries, the efficiency is as loftier as 97 %.
Another thing that needs to exist kept in mind when calculating charge time is that the last 20 % of the charging procedure (from 80 to 100 %) takes around 4 hours with wet, gel and AGM batteries (this does not apply to Lithium Ion batteries). In the second stage, also chosen the assimilation or subsequently-accuse phase, the type of bombardment determines how much current is being absorbed, independently of the capacity of the bombardment charger.
The after-charge phase phenomenon again does not apply to Lithium Ion batteries, which are charged much faster.
The harmful furnishings of ripple voltage on batteries
A battery can get prematurely defective due to the ripple voltage produced by bombardment chargers. To prevent this, the ripple voltage acquired by a charger should remain as low as possible.
The ripple voltage results in ripple current. As a rule of thumb, the ripple current should remain below 5 per cent of installed battery capacity. If navigation or communications equipment such as GPS or VHF devices is connected to the battery, the ripple voltage should exist no more than 100 mV (0.i V). Any more than could cause the equipment to malfunction.
Mastervolt battery chargers are equipped with first-class voltage regulation and the ripple voltage they produce is always lower than 100 mV.
Another advantage of low ripple voltage is to preclude damage to the system if, for example, a battery terminal is not properly secured or is corroded. Thanks to its depression ripple voltage, a Mastervolt battery charger can even supply the organization without being attached to a battery pack.
Finding the country of charge of a battery
The adjacent explanation regarding the Peukert exponent shows that the country of charge of a battery cannot but be adamant based on, for instance, measuring battery voltage.
The best and most accurate manner to check the state of charge is to use an amp hour meter (battery monitor). An instance of such a meter is the Mastervolt MasterShunt, BTM-Iii or BattMan bombardment monitor. In addition to the charge and discharge current, this monitor also indicates battery voltage, the number of amp-hours consumed, and the time remaining until the bombardment bank needs recharging.
1 of the things that set the Mastervolt bombardment monitor apart from other suppliers is the availability of historical information. This shows, for example, the charge/belch cycles of the battery, the deepest discharge, the average discharge, and the highest and lowest measured voltage.
Peukert's Law
On the surface it seems easy to calculate how much longer a battery volition go along to supply sufficient power. One of the most common methods is to divide battery capacity by discharge current. In do, however, such calculations ofttimes plough out to be incorrect. Most battery manufacturers specify battery capacity assuming a discharge time of 20 hours. A 100 Ah bombardment, for example, is supposed to deliver v amps per hour for 20 hours, during which time voltage should not driblet beneath ten.v volt (1.75 Five/prison cell) for a 12 V battery. Unfortunately, when discharged at a current level of 100 amps, a 100 Ah bombardment will evangelize just 45 Ah, significant that it can only exist used for less than 30 minutes.
This phenomenon is described in a formula – Peukert's Law – devised more than than a century ago by the battery pioneers Peukert (1897) and Schroder (1894). Peukert's Law describes the effect of different discharge values on the capacity of a battery, i.due east. that battery capacity is reduced at higher discharge rates. All Mastervolt battery monitors take this equation into account and so you will always know the right status of your batteries.
Peukert's Law does not apply for Lithium Ion batteries as the connected load will take no effect on the bachelor chapters.
The Peukert formula for battery capacity at a given discharge current is:
Cp = battery capacity bachelor with the given discharge current
I = the discharge current level
n = the Peukert exponent = log T2 - logT1 : log I1 - log I2
T = discharge fourth dimension in hours
I1, I2 and T1, T2 tin can be found by conveying out two discharge tests. This involves draining the battery twice at two different current levels.
I loftier (I1) – 50 % of bombardment chapters, say – and one low (I2) – effectually 5 %. In each of the tests, the time T1 and T2 that passes before battery voltage has dropped to 10.5 volt is recorded. Carrying out 2 belch tests is not e'er elementary. Ofttimes, no large load will exist available or in that location will be no time for a slow discharge examination. Yous can remember the information necessary for calculating the Peukert exponent from the specifications of the bombardment.
Ventilation
Under normal weather, gel, AGM and Lithium Ion batteries produce little or no dangerous hydrogen gas. The picayune gas that escapes is negligible. However, simply like with all other batteries, estrus is generated during charging. To ensure the longest possible lifespan, information technology is of import for this oestrus to be removed from the bombardment equally apace as possible. The following formula can exist used to calculate the ventilation required for Mastervolt bombardment chargers.
Q = required ventilation in m³/h
I = maximum charge electric current of the battery charger
f1 = 0.v reduction for Gel batteries
f2 = 0.v reduction for closed batteries
n = number of cells used (a 12-volt battery has six cells of 2 volt each)
Returning to the example of a 12 V/400 Ah battery gear up and an 80-amp charger, the minimum ventilation necessary will be: Q = 0.05 x fourscore x 0.5 x 0.five ten six = half-dozen m³/h
This air flow is so small that normally natural ventilation will be sufficient. If the batteries are installed in a closed casing, two openings will be needed: I on the height and 1 underneath. The dimensions of the ventilation opening can exist calculated using the post-obit formula:
A = opening in cm²
Q = ventilation in thousand³
In our case, this amounts to 28 10 6 = 168 cm² (around 10 ten 17 cm) for each opening.
Lithium Ion batteries do not produce whatsoever hydrogen gas and are therefore safe to employ. When batteries are charged quickly there is some degree of heat production, in which case the higher up formula can be used to remove the heat.
Contact your installer for larger systems with multiple bombardment chargers.
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Source: https://www.mastervolt.com/charging-batteries/
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