Stack two lipo shorty packs

[TeknoHov]

Hi All,

Looking to run two 2S shorty packs in am ET 48 2.0, and to run one of the 2S shorty packs in an ET410.2

I'm concerned if the packs might short out in the ET 48, would the intellect battery stopper https://www.modelsport.co.uk/product/intellect-battery-stopper-pk10-437699 help/stop shorting if packs stacked with the connectors the same end?

Cheers!

 

[Billl DeLong]

Folks have been running shorty packs in series for years, but 5Ah probably won't make a 10 min main in
the truggy class.

The bigger concern is that you can't split the packs up once they are paired in series as they will no longer be a "matched pair" and will drain out of balance causing premature failures when you switch back to series configuration, more info here:

https://www.smc-racing.net/index.php?route=product/category&path=166

 

[TeknoHov]

@Billl DeLong ,

Very insightful as I hadn't considered those factors at all.

I’ll not be racing, but now appreciate alternating 1A-1B, 1B-1A for example, and checking the LVC.

If I run them in the ET410 then I’d need to ensure alternating 1A, 1B etc.

I can’t seem to find any pictures of the shorty orientation, whether the bullet connections are at different ends, or stacked on top of each other/same ends…

Thanks again

 

[Billl DeLong]

Fair warning, before the SMC article was published, I used to mix match 2S batteries that I raced in my 4WD SCT to run in series with my eBuggy and it seemed to work fine for about a month then I started getting premature LVC's where 1 pack started swelling up pretty bad, I replaced it with a brand new battery and that pack subsequently swelled up within a handful of uses.

I found it to be more cost effective to run a single 4S pack in my eBuggy and no longer ran packs in series.

If I were to run 2x2S shorty packs then I would buy a design which offers "through and through " connectors so you can flip 1 pack over and solder two 5mm bullets so they make a double male adapter to join both packs back to back making it the most efficient connection possible. Then you can connect the pack just like any other shorty pack.

 

[TeknoHov]

Thanks again @Billl DeLong ,

Its all logical and sound advice, once you're made aware of the caveats, which I thank you for.

I've ordered and received my 2 packs, and will look at the through and through as you mentioned.

Did you put any padding between the packs when stacked, i.e. due to the bullet connectors sitting higher than the top of the battery pack?

My benefit of 2 packs in series beng I can charge both packs at the same time in theory halving the charding and storage mode charging, and use (rotate) one pack in an ET410 (in the futurte).

Cheers!

 

[Billl DeLong]

I didn't place any padding in between, I simply taped them together. I also placed them on their sides to get them to fit properly in the velcro straps.

Once you start using a pack in the ET410, then I wouldn't put it in series back in the buggy after that point.