Car battery charging voltage

[chatelot16]

to protect the battery from excessive discharge by measuring the voltage during discharge it is necessary to take into account its real voltage drop due to the current

cut to 12 volts if there is a very low current

cut to 10.5 for a stronger current

it is even tolerable to drop to less than 10V during high current peaks

but problem, the voltage drop is completely variable with the state of wear of the battery: so for me the only reliable way not to over-discharge is to measure the voltage without current

I prefer 2 batteries which will last a long time rather than one which will not hold

[Christophe]

We agree

[darwenn]

Interesting all these details. My inverter cuts off at 11,5 volts. So no worries about draining the battery at the risk of shooting it. In the event of the battery being discharged, a relay system will switch to a second battery which will be charged, while the other will switch to charging.

[Alain G]

to protect the battery from excessive discharge by measuring the voltage during discharge it is necessary to take into account its real voltage drop due to the current

cut to 12 volts if there is a very low current

cut to 10.5 for a stronger current

it is even tolerable to drop to less than 10V during high current peaks

but problem, the voltage drop is completely variable with the state of wear of the battery: so for me the only reliable way not to over-discharge is to measure the voltage without current

I prefer 2 batteries which will last a long time rather than one which will not hold

Hello Chatelot!

I repaired rolling material handling equipment such as forklift, scissor platform etc. a few years ago, as well as battery repair (cell replacement).

Always check the battery voltage with an applied load and not empty.

[Alain G]

Interesting all these details. My inverter cuts off at 11,5 volts. So no worries about draining the battery at the risk of shooting it. In the event of the battery being discharged, a relay system will switch to a second battery which will be charged, while the other will switch to charging.

Darwenn

The correct voltage is 10,5 volts as mentioned by christophe, but be careful if the inverter delivers little in watts, it may be triggered higher voltage , the reason is quite simple, these inverters are calculated for a use of car batteries, for a battery cap totaling 600 amps a voltage of 10,5 volts is too low because the load in amps is not high enough and the batteries will be too low.

The ideal is an independent protection or an inverter where one could enter the amperage value of the battery pack which would itself calculate the safety voltage.


Sorry, I wrote lower voltage and it should have been higher.

[Other]

Hello

Delco Rémy alternator on most American cars is 14,4 volts
On boats, planes, stationary vehicles, it is 13,8 volts

A car battery supports very well 14,4 volts once this voltag is reached, there is almost nothing left in the battery.
where it becomes complicated it is when the battery has a weak cell it can no longer reach its 14,4 volts and it always charges which causes the water to evaporate

To reduce the voltage with an auto alternator it is enough simply to put a diode in series the regulator maintains 14,4 and at the output of the diode there is 13,8 v

Andre