Charging 2/3 battery packs for crawling

[prontozuk]

I am starting to get in to the 1/16 and 1/18 and a lot of them are coming with 2/3 6 and 7 cell nimh battery packs. I have been using the charger that comes with them. However it is an overnight charger.. Would it be ok to use the charges I have for these types of battery packs. I have got Ansmann G167N AC/DC Nicad/Nimh Battery charger 7.2v and a Duratrax Piranha DC Peak Charger both displayed below. Or should I look for a charger for specific to 2/3 battery packs. Also I have thought about running 2 of the 2/3 6 and 7 cell battery packs together on my AX10 to spread the weight around have one on the front diff and one on the rear diff using something like a parallel battery connector like the one pictured below.

Thanks James

 

[Sharkey]

the problem with a cheaper chargers is they are designed for sub c packs and have a fixed charge current for only those. 2/3a cells dont like being charged at more than 2 amps. charging at too high an amperage will overheat the cells and end up killing them.

my recomendation is to spend some money on a good charger with more adjustability, something like an duratrax onyx 220, or a 230 if you want to do lipo in the future (if your into the smaller cars, lipo is the way to go).

 

[Manning]

Do not use the Piranha, it charges at 4 amps (says so on the label), which is much too high for 2/3A packs. Don't know what the output is on the other.

1.5 amps max on 2/3A packs if you want them to last. Lower is better, but as you know, it takes longer.

 

[prontozuk]

sorry if this sounds like a stupid and dangerous question but can I use my current chargers if I put two of the 2/3 packs together in parallel so instead of charging a 1600nimh 2/3 pack it would be a 3200nimh 2/3 pack (2 x 1600nimh)

Thank James

 

[JohnRobHolmes]

You can't charge nimh in parallel without some extra hardware. When one pack gets charged first, it will lower in resistance a bit and want to take even more charge compared to the less-full pack. The full pack gets too much and will overheat.

Charge them one at a time, or get two chargers.

 

[prontozuk]

Ok it is now drummed in to my head get a new charger for 2/3 packs."thumbsup"

So is there really any true benefit with running 2 x 2/3 battery packs at with either 7.2v or 8.4v configuration together in parallel lets say over a 7.2v 4200?

Or will I get a similar problem with one battery discharging quicker than the other second battery and it just getting really hot….?

Once again I am sorry for all the stupid questions.



Thanks James

 

[JohnRobHolmes]

Better weight placement with smaller cells. Not a problem running them in paralllel during discharge.