Hota D6 Pro and NiMH packs

[desmobob]

Today I received my first 6-cell NiMH stick pack for my Tamiya Hornet Evo. It's a Zee brand 3600mah pack.

I just charged it for the first time (at 1.8A -- .5C) using my Hota D6 Pro and I was surprised how warm the pack was when finished charging. It's not too warm to hold, but it's warmer than I expected. I charge a lot of AA and AAA NiMH batteries and I know they get warm.

The information for the pack says it's capable of 5C charging(!), which I would probably never try. Is .5C too aggressive?

 

[Lostinthewoods86]

Right or wrong, I’ve done 2c rates on the nimh batteries. They are always hot, but no issues to date

 

[Ritz413]

When I charge my nimh aas for the remote, I use std 4x and 8x appropriate chargers and they always come off warmer than I expect.

 

[Cranberry Juice]

When I used to run NiMH packs on the Ruckus they would finish charging warmer than I thought was safe. LiPo packs seem to charge cooler. I definitely wouldn't charge a NiMH on 5C, 2C is the highest I'd go just because they tend to be a bit more finicky than LiPos.

 

[RustyUs]

Today I received my first 6-cell NiMH stick pack for my Tamiya Hornet Evo. It's a Zee brand 3600mah pack.

I just charged it for the first time (at 1.8A -- .5C) using my Hota D6 Pro and I was surprised how warm the pack was when finished charging. It's not too warm to hold, but it's warmer than I expected. I charge a lot of AA and AAA NiMH batteries and I know they get warm.

The information for the pack says it's capable of 5C charging(!), which I would probably never try. Is .5C too aggressive?

.5C is what I'd do for normal everyday charging. It's been a long time since I raced with NiMh packs... 2C charge rates... I wanted the packs pretty warm when putting buggy on the track.

Default delta peak value on the charger is 4mV/cell?

 

[desmobob]

.5C is what I'd do for normal everyday charging. It's been a long time since I raced with NiMh packs... 2C charge rates... I wanted the packs pretty warm when putting buggy on the track.

Default delta peak value on the charger is 4mV/cell?

The -deltaV was set to 7mV. Should I change it to 4mV? I did some searching and the few references I found said a -deltaV between 3mv and 5mv was recommended.

 

[RustyUs]

The -deltaV was set to 7mV. Should I change it to 4mV? I did some searching and the few references I found said a -deltaV between 3mv and 5mv was recommended.

It's been so long since I messed with NiMh packs I don't remember exactly where I had my charger set at. I just know default -ΔV settings can vary from charger to charger. I have not dug into NiMh settings on my Hota chargers to see what the default is.

 

[desmobob]

And on the subject of NiMH packs, I've read that the ideal storage charge is 40-50%. My Hota D6 Pro does not offer "Storage" as a charging setting when NiMH is selected for the battery type.

I've read that storage while depleted is tough on NiMH so I'll be guessing at my storage level to avoid putting them away dead. Is there a pack voltage reading that would approximate 50% charge?

 

[Rocketzx1]

And on the subject of NiMH packs, I've read that the ideal storage charge is 40-50%. My Hota D6 Pro does not offer "Storage" as a charging setting when NiMH is selected for the battery type.

I've read that storage while depleted is tough on NiMH so I'll be guessing at my storage level to avoid putting them away dead. Is there a pack voltage reading that would approximate 50% charge?

You don't storage charge NiMH packs, that is why there is not a setting for it. Just charge it to full and the NiMH battery will self discharge over time. If you're storing the NiMH battery for more than a couple weeks, you need to charge it back to full and store it in a cool place, roughly 55-70 degrees Fahrenheit and when you do go to use the NiMH battery, let it sit in the house and warm up to room temperature, charge it to full, run it like normal to roughly 20%, and put back on the charger to kick start the chemistry.

NiMH batteries will be warm at the end of charging them, it is normal for them to be warm to the touch.