Advice on charging NiMH battery procedure

[BrianWP]

I’m still a novice so forgive what may seem a daft question! Is it possible to modify the battery connection on my (almost completed) Tamiya Toyota Mountain Rider with an additional connector that’s accessible for charging so I don’t need to unplug the battery from the ESC each time? Thx

[Matty36]

I would never leave the battery plugged in or even in the car when not in use. I would remove the battery when charging anyway in case it has a fault as it's cheaper to replace the battery rather than replace an esc as well. Now I use lipo, they need to be charged in a safe bag, away from most things.

[BrianWP]

1 hour ago, BrianWP said:

I’m still a novice so forgive what may seem a daft question! Is it possible to modify the battery connection on my (almost completed) Tamiya Toyota Mountain Rider with an additional connector that’s accessible for charging so I don’t need to unplug the battery from the ESC each time? Thx*

27 minutes ago, Matty36 said:

I would never leave the battery plugged in or even in the car when not in use. I would remove the battery when charging anyway in case it has a fault as it's cheaper to replace the battery rather than replace an esc as well. Now I use lipo, they need to be charged in a safe bag, away from most things.

Many thanks for your advice & I certainly appreciate what your saying. In my case the body shell has a wiring loom for max lighting mods, so there are three additional connectors that require disconnecting to lift the body clear enough for easy battery removal. So I can’t help remaining envious of models that have a charging point which, I image, disconnect the ESC.

[Nick G]

I've built charging points into a couple of my tanks running NiCads . They work ok, yes it's better to disconnect the battery when not in use but a couple of them are complete ******s to get at ! I would never do it with Lipos , too volatile and need the balance lead connected. 

[Juggular]

All batteries discharge when left alone.  That gets accelerated when things are connected to it.  Even if ESC is off.  More wires for electrons to escape to.  With LiPo's tendency to catch fire when over-drained, your Mountain Rider might spontaneously catch fire if you don't have a habit of disconnecting after every use.  If you have many wires, I feel your pain, though.  

 

 

[whahooo]

Is there a safe Tutorial how to charge NiMhs?

I never know how to charge them right.

I always discharge them befor i charge them. But i have 2 faulty Chargers. The first has sometimes stop charging because the connector is a little bit loose.... 

What schould i do with an half or quater charges Battery? Discharge it or charge it full?

My second Charger doesnt discharge enough befor it starts the charging.....

 

Then i have a LRP Quadra Charger that works great, but it is for NiCads and not for NiMhs.....

 

I would love to throw all of my Nicads away and only use modern NiMhs with a good charger.

[Aerobert]

5 hours ago, BrianWP said:

I’m still a novice so forgive what may seem a daft question! Is it possible to modify the battery connection on my (almost completed) Tamiya Toyota Mountain Rider with an additional connector that’s accessible for charging so I don’t need to unplug the battery from the ESC each time? Thx

Instead of build in an additional connector for charging the battery in the car you may think about to work over your light connectors. Maybe something like this will make it easier to remove the shell.

https://www.boomracingrc.com/boom-racing-stealth-wireless-magnetic-led-body-mount-3116

Or you put all connectors in one like these:

https://www.multiplex-rc.de/produkte/1-01219-mpx-stecker-m6-50-3-stueck-made-in-germany

Will make your battery charging for sure easier. 

[BrianWP]

Thanks everyone, especially Aerobert. I’ve not seen the magnetic connectors before. I’m thinking perhaps I could achieve my wish if I include a cut off switch to the ESC. But can anyone tell me how some manufactures manage to do it?

[Juggular]

3 hours ago, whahooo said:

What schould i do with an half or quater charges Battery? Discharge it or charge it full?

With NiMH, the memory effect is less than NiCd.  But I'd still do full charge/full drain.  Well, not quite 100% drain because that will kill it.  Discharge to about 1v or 0.9volt per cell.  That'd be 6v, or 5.4v.  You'll feel the car driving not as peppy as it was for the past 15 minutes. (definitely not to a crawl) 

Let it cool, and charge fully.  If next run is a month later, I would discharge, cool, and recharge.  

 

[whahooo]

Thanks!

 

And if i run a car only 10 minutes it is ok to run it again a month later to use the rest of the battery?

[BrianWP]

On 9/6/2020 at 10:45 PM, Juggular said:

With NiMH, the memory effect is less than NiCd.  But I'd still do full charge/full drain.  Well, not quite 100% drain because that will kill it.  Discharge to about 1v or 0.9volt per cell.  That'd be 6v, or 5.4v.  You'll feel the car driving not as peppy as it was for the past 15 minutes. (definitely not to a crawl) 

Let it cool, and charge fully.  If next run is a month later, I would discharge, cool, and recharge.  

 

Thanks Juggular, so how have you wired it? Do you disconnect the ESC or have you a component between the battery and the ESC? I have it in my mind that I once saw a “kit” to do this on HobbyKing” but can’t find it now of course! I have new NiMH batts.

[Juggular]

If you want to keep the battery in, I would lengthen the wire so you can disconnect without bothering the shell.  Or build an adapter to make it long.  

I had once thought about using a switch.  Like 60A breakers used at home... but those things are just massive.  Smaller switches cannot let through 60A that ESCs can handle.  

Here is a photo of 40A breaker just for one line. You'd need 2 of these.  That's why it's just easier to unplug if you have longer wires.   

[BrianWP]

Ok, so I’ll lengthen the cables so I can access the plug without body shell removal. Thanks so much for your help.