Fast charge slow charge

[Maximuswood]

Hi. I was reading that it is bad to fast charge batteries, so if i wanted to recharge 600w to a new battery, id have to do it at a rate of 24w instead of 250w+ for a slow charge.

Dangers of fast charge in lead acid bat is gas production, hydrogen,  hydrogen sulfide.

 

[highdesertranger]

what does the battery manufacturer recommend? your use of watts is confusing, when talking batteries and charging, amps is the usual unit that is used. 24watts @ 12v is only 2amps you are not going to charge much with that. 250watts @ 12v would by 20amps and that could work for some batteries. like I said what does the manufacturer recommend. highdesertranger

 

[Maximuswood]

Ill check the manufacturer's recommendations. This is one of the things i read online..

Most battery chargers offer two different rates of charge. The slow rate is 2amps, and the fast rate is 6amps or 10amps, depending on the charger. It is always better for the battery, and safer for the owner, to charge at the 2 amp rate. It produces less heat and stress on the battery,

 

[highdesertranger]

don't believe everything you read on the internet. that is very bad advice.

however that sounds like a dumb charger which you shouldn't be using if you want to have maximum battery life.

exactly what battery and charger do you have and what are you trying to do with it?

as a side note there are several people on the forum with much more knowledge than me on this subject, give them some time and they will chime in.

highdesertranger

 

[B and C]

It sounds like you are looking at cheap homeowner chargers for that info. Mine here at the house is 2-10-50 amps and is a cheap Schumacher I've had for years. The battery manufacturer is the real authority on how their battery should be charged.

 

[Elbear1]

Charging is based on internal resistance. As it fills the resistance goes up. So fast charge when low and slow it down as it fills above 80%. Gassing happens when you push current beyond the internal resistance. Some gassing is expected and needed in deep cycles.

 

[tx2sturgis]

In addition to the above replies, flooded batteries are purposely 'fast charged' (or over-charged) during the equalization mode that is often performed (by some chargers and solar controllers) every 2 to 4 weeks, especially when the batteries are not in a vehicle, ie, in a home-based solar or backup power platform.

This is done to de-stratify or 'stir' the liquid electrolyte, causing bubbles that form on the plates and then they move upwards, causing activity in the fluid....we see this as 'bubbling' in the top of the battery under the caps.

So, sometimes fast charging is good for the battery....it just depends on what kind of battery and how it is being used.

 

[jonyjoe303]

Even 10 amps is trickle charging for most lead acid batteries. 50 amps would be fast charging but you won't see that with solar. Just because the charger can put out 50 amps doesnt mean the battery will take it. You can't overcharge your lead acid, the higher the battery voltage, the less amps the battery takes.

Some lead acid like agm's prefer fast charge at high amps, they last longer the more you fully charge them.

Its best to fast charge your battery everyday, then to slow charge and risk undercharging them.

What will cause problems is if the charger voltage is too high (above 14.4 volts) then your cooking your batteries.

 

[highdesertranger]

" You can't overcharge your lead acid"

yes you can

"What will cause problems is if the charger voltage is too high (above 14.4 volts) then your cooking your batteries"

see you can, you answered your own statement

if you couldn't over charge them there would be no need for chargers with multiple stages.

highdesertranger

 

[Master Mechanic]

Hi. I was reading that it is bad to fast charge batteries, so if i wanted to recharge 600w to a new battery, id have to do it at a rate of 24w instead of 250w+ for a slow charge.

Dangers of fast charge in lead acid bat is gas production, hydrogen,  hydrogen sulfide.

first get setting from battery manufacturer. all are different do not quess.
charge controller will charge it as needed in 3 stages. u need to set it correctly. it knows what to do then.
battery charger if battery manufacturer says max 30 amp charge rate use that setting or buy one with that amp rating. it will charge as needed