Battery Theory

[MagicianElectrician]

Correct me if I'm wrong, but would it not be better to use individual 1S batteries and wire em together in series with an adapter or whatever to get the voltage you need for your build at the time as opposed to having a premade 2S, 3S or 4S battery? Then you could charge them individually and make absolute certain they're balanced instead of relying on balance leads to do it. Not only that, but you could easily rotate the batteries in the group so one is not overused. Premade batteries are stuck in their arrangement. I know it would be more work to charge them, yes, but what does everyone think?

 

[Beer_Goggles_RC]

Correct me if I'm wrong, but would it not be better to use individual 1S batteries and wire em together in series with an adapter or whatever to get the voltage you need for your build at the time as opposed to having a premade 2S, 3S or 4S battery? Then you could charge them individually and make absolute certain they're balanced instead of relying on balance leads to do it. Not only that, but you could easily rotate the batteries in the group so one is not overused. Premade batteries are stuck in their arrangement. I know it would be more work to charge them, yes, but what does everyone think?

I mean, i suppose you could. But i dont think it would be optimal for performance or convenience. maybe save you a few bucks if each rig takes the same size battery and you want to run the same mah for everything.

a few other things that come to mind;
Voltage sag at each connector. Having to charge each battery individually (a balance charger typically does pretty well). Wiring mess.

I think I'd rather have a single battery for every rig

 

[CertifiedMike]

Hard case packs are required for racing. 1s packs are outlawed in 1/10 scale.
Wiring and multi connectors as fail points, harder to secure 2 small pack than 1 large pack seem like issues I'd like to avoid.
Seems like a capable charger can balance easy enough.

 

[WickedFog]

What these guys said

You're going to have a pretty terrible pack that way, because instead of having low resistance metal tabs connecting the cells, you'll have wires and connectors.

 

[MagicianElectrician]

Hard case packs are required for racing. 1s packs are outlawed in 1/10 scale.
Wiring and multi connectors as fail points, harder to secure 2 small pack than 1 large pack seem like issues I'd like to avoid.
Seems like a capable charger can balance easy enough.

Ah ha. Ok. Thats something I wasn't aware of. Makes sense.

 

[MagicianElectrician]

What these guys said

You're going to have a pretty terrible pack that way, because instead of having low resistance metal tabs connecting the cells, you'll have wires and connectors.

A good connection between them and you would never know the difference.

 

[MagicianElectrician]

What made me wonder about this is: say you have a 3S battery that won't charge. It's most likely because 1 of the cells in the pack is bad from either overheating or voltage got too low from not balance charging or whatever. So then the other 2 cells that are actually still good have to get trashed along with the bad cell for no reason when you could just pull the bad one and insert a new 1S in its place. That's where I was going with this

 

[WickedFog]

A good connection between them and you would never know the difference.

For a high amp draw esc/motor setup you likely would. I'd be curious to see a voltage sag and actual c rating comparison between a pack built like this and a standard high C rated pack.

 

[CreepyQuarryCrawler]

In my experience, when a multi cell battery looks good but doesn't want to charge it's usually due to a broken wire (balance lead). Which is typically repairable, and I have done it.

If it's puffed beyond a reasonable state then I would call that battery bad, anyway.

This just seems like a lot of work that someone else has already done.

Good batteries have matched cells so they have similar discharge rates along with matched internal resistance.

 

[tudordewolf]

You could certainly try, you'll find pretty quickly that the drawbacks outweigh the benefits.

One of the big ones is charging, with a balance lead and modern chargers you basically are charging all the cells individually. With a quad charger and 6s packs, you can charge 24 cells at once - doing them all individually by hand would take ages.

I agree that a single bad cell causing the disposal of an entire pack is unfortunate, but you have to ask yourself, what killed that cell, and how healthy are the others? It's possible they're only a few cycles away from failing themselves, if they were subjected to the same conditions that caused the first one to fail. Modern packs are so reliable that bad cells are pretty uncommon, and only people that are really pushing their packs to the max are going to be killing cells with any regularity.

 

[MagicianElectrician]

You do have a point there sir. Well, I just got done ordering a new 3S battery for my Backslash and a 2S for my little nephews Teton. My Traxxas 3S was degrading and finally swelled up. No longer usable. I went with HRB 3S 5000mah 120C. I'll give it a try