losifan94

I was told that if I charged my battery to slow it will ruin the battery. Is this true?

JimmyG

Battery type??

What is a "slow" charge rate ?

Duster_360

iTrader: (21)

^^^+1 - we need more info.....

losifan94

Like if I charge my nimh at around .5 amps when its a 1600mah 5 cell flat pack. A slow charge is when you use very little amps.

Dave H

Typically there are only 2 cases where a low charge rate can be harmful. If you peak detect charge Ni-xx cells at too low of a rate, the peak detection deal may not be accurate, can lead to either under or over charge. Or if you trickle charge same (overnight wall warts) for an extended time (days), not good. (also for auto - lead acids)

0.5 amps on that pack sounds fine. Don’t want to go much lower though for a good peak. Depending on quality of cells might be able to go a little higher.

burnineyes

iTrader: (17)

No, 0.5A is good for 1600mah 2/3A cells. The reason they are asking for more info is not because we dont know what a slow charge rate is, but because it is subjective to the type of battery being charged. 0.5A may be a slow rate for a 6500mah lipo pack, but it is actually not that slow for a 1600mah 2/3A pack. I personally would not charge the 1600mah pack over 1A because I have seen them heat up fast when the current is too high. Make sure your peak detection is set correctly and everything will be fine.

stu22

Assuming that your talking about NiMH, it's not slow charging but over charging that's the issue.

If you put a NiMH on a charger, let it get to full charge by either fast or slow charging it, and then let it sit with even a very low trickle current through it, you will be over charging and reducing it's life.

You see this more for people using rechargable AAA/AA/C/D cells in their consumer electronics and just leave them in the charging station or in something with a battery pack that sits on it's charger all the time (wrecked the pack for my first Roomba this way.)

In general, slow charging will extend the life of a pack (there's a thread on this board somewhere where someone proved this for LiPo packs by charging one at 1C and it's twin at a higher current and actually gathered data.) Although I really don't notice a difference, I've been told that charging at a higher current will give more punch from the pack.

losifan94

Ok thanks guys because I wasn't sure if charging the pack for almost 3 hours on a .5 amp charge would ruin it. Thanks all

upDUHcreek

That shouldn't ruin your pack. The only problem I've noticed when slow charging NiMH packs, is they won't like being charged quickly any more. If you try to fast charge them, they will most likely false peak before they are fully charged.