When to charge a 6V 4Ah SLA battery and can I charge it this way?

Hi. I need a battery for my project which will use around 4A, so I decided to buy a SLA (6V 4Ah), thinking well it is 6V and I have a power supply uniit which is 6V 20A, so it should be aesy to charge it. But damn, it is seriosly hard to charge a battery by yourself. But as a broke student I want to keep things simple, since I don't need the battery to work for years right now.

I am buying a step down voltage regulator (to use it on arduino), and I have a 12V 1A adaptor. Setting this regulator to 6.8V and connecting it to adaptor, can I charge the battery without burning my house down?

And at what volt should I consider charging the battery?

Most important, don't leave a lead-acid battery partially discharged for long periods. Make sure it gets a very full charge at least once per week.

You have not told us what you want to use the battery for - for example, how long a single running session might be? Ideally recharge the battery after every running session.

Have a look at the Battery University website for all the info you need.

...R

Robin2:
Most important, don't leave a lead-acid battery partially discharged for long periods. Make sure it gets a very full charge at least once per week.

You have not told us what you want to use the battery for - for example, how long a single running session might be? Ideally recharge the battery after every running session.

Have a look at the Battery University website for all the info you need.

...R

I will use it on mobile robotic arm, It won't work more than 10 minutes, I will probably won't use it that much either.

I looked at these kind of sites, and they say I need to regulate amps, but for that I should buy more stuff, which is a luxury right now. So my questions stands, can I charge the battery this whay and at what volt I should be alarmed to charge?

compnaion:
at what volt I should be alarmed to charge?

If that means "what is the lowest voltage I can discharge the battery to before I MUST charge it" then that info will be in the link I have you. However, as I said earlier it would be best to recharge the battery after every running session.

Charging the battery with a 6.8v charger won't do the battery any harm. However if the battery is deeply discharged it may take 10 or more amps from the charger - can the charger survive that?

When my 12v battery is being charged at 14.9v it can draw 50 amps or more.

I don't understand your reference to a 6v 20 amp power supply in your Original Post - what role will it be playing?

...R

PS ... don't expect to get 4Ah regularly from what the manufacturer describes as a 4Ah battery. 50% of that is more likely.

Robin2:
If that means "what is the lowest voltage I can discharge the battery to before I MUST charge it" then that info will be in the link I have you. However, as I said earlier it would be best to recharge the battery after every running session.

Charging the battery with a 6.8v charger won't do the battery any harm. However if the battery is deeply discharged it may take 10 or more amps from the charger - can the charger survive that?

When my 12v battery is being charged at 14.9v it can draw 50 amps or more.

I don't understand your reference to a 6v 20 amp power supply in your Original Post - what role will it be playing?

...R

PS ... don't expect to get 4Ah regularly from what the manufacturer describes as a 4Ah battery. 50% of that is more likely.

That power supply was for other projects, I thought to connect the battery to that power supply, but everywhere I looked they said limit the current, so I cannot use that for charging. But as I understand from your comment as long as I don't drain the battery, which I won't, I am OK to charge it with adaptor and stepdown regulator.
That being said I don't really care about Ah that much, it's a school project, as long as it works for few minutes, powering the system more efficiently will be a later project for me. For now I am just trying to save the day.

compnaion:
That power supply was for other projects, I thought to connect the battery to that power supply, but everywhere I looked they said limit the current, so I cannot use that for charging.

The 6v 20A power supply may be more suitable for charging than 6.8v at 1 amp. You need to understand that it is the device that is consuming power that determines how many amps flow. Having excess amps available is no problem. Having too few usually means that the power supply is overloaded and cuts out or gets destroyed.

The real problem with the 6v power supply is that the voltage is not high enough to charge a 6v battery properly. The Battery University will have data for the appropriate charge voltage. The trickle-charge voltage is probably about 6.5v.

If you don't want to spend money on a proper charger then you need to do a lot more learning - no such thing as a free lunch. :slight_smile:

...R

Robin2:
The 6v 20A power supply may be more suitable for charging than 6.8v at 1 amp. You need to understand that it is the device that is consuming power that determines how many amps flow. Having excess amps available is no problem. Having too few usually means that the power supply is overloaded and cuts out or gets destroyed.

The real problem with the 6v power supply is that the voltage is not high enough to charge a 6v battery properly. The Battery University will have data for the appropriate charge voltage. The trickle-charge voltage is probably about 6.5v.

If you don't want to spend money on a proper charger then you need to do a lot more learning - no such thing as a free lunch. :slight_smile:

...R

I see, It seems I have to learn more :). Thank you very much for your help.