Two 6S 5000 mAh same as one 6S 10000 mAh?

[ScarabChris]

Some of you might remember my 52" Fountain build. I was running two 6S 5000 mAh (40-50C) batteries per motor/ESC.

Well it has been over a year since running the boat and I ran it for the first time yesterday. Like a dope I put the boat in storage with all the batteries discharged and was only able to get 2 of the 4 to take a charge.

The boat ran very well, forgot how fun it was. I only ran it for about 10 minutes at varying speeds and assume I didn't have much time left before the LVC kicked in.

So on to the question. I was thinking of buying two 6S 10,000 batteries and keeping the system with 2 batteries. Just for the sake of cutting down on the wiring and carrying of batteries.

Should I expect the same results going from two 5000 to a single 10000?118161

[785boats]

Chris.
The answer is yes.
But why wouldn't the other batteries take a charge.
What were the individual cell voltages after being in storage for so long?
Is there any sign of puffing?
What was your charger telling you when you tried to charge them?
They may be salvageable.

[ScarabChris]

Yes one battery was extremely puffy after taking them from storage. Only reads 15 volts when trying to charge then the charger (Hyperion EOS 0720i) instantly sounds an alarm and reads "battery output connect error"

One battery charges perfectly. The remaining two will start to take a charge then when nearing the end they will read the same "battery output connect error" but they will take enough of a charge to run the boat. But I suspect they are on their way out. So instead of buying 3 new 5000 batteries I was thinking of buying two new 10000 batteries.

[Brushless55]

if you buy two 10,000mah packs then they will be dedicated to this boat...
or any large setup you have
I do like the idea of having smaller 6s packs to power several things
but that's me :biggrin:

[785boats]

Chris.
The puffy one is definitely a throw away item.
The two that charge & then cutout on the output error may be ok.
Firstly, disconnect & reconnect the balance plugs from the charger & the balance board a few times. There might be some slight corrosion on some pins & the resistance is such that when the charger is near the end of the charge in the CV mode, & only putting a couple of hundred milliamps through the connections, it can read it as an open circuit.
What are the individual cell voltages when the charger cuts out?

[MarkF]

Chris

Going from 2 5000 packs to 1 10,000 pack will be better. You have less wiring, less chance of a cell going bad not to mention less internal resistance and less hassle to set up and charge. To me it's a win win situation.
In case you haven't heard I have 6s 10,000 mah packs on my site. http://dinogylipos.com/6s-lipos/152-10000mah-6s-35c

Mark

[keithbradley]

Chris

less internal resistance and less hassle to set up and charge.

Wouldn't you assume a greater total resistance at the plugs compared to (2) 5000mah packs, since you have half the amount of wire connecting to your ESC?

EDIT: I do think the single 10,000mah pack would be simpler, easier if you have plenty of room...just wondering the science behind the above statement.

[MarkF]

It's basic science. Less wire,connectors and cells. What's not to understand. Guys are charging these packs at 20 to 30 amps to speed up charge time. Who cares what the plugs are seeing. If your plugs are getting hot then your not using the right plugs.
My customers tell me there IR numbers are .7 to 1s across the board on my 10,000 mah packs. A larger cell format not only delivers better performance but is more robust against higher amp draw. I asked the factory if they would make me some 65c 10,000 cells and they said why? It's not needed. That wasn't the answer I was looking for from them and this is the reason they gave me.
They said it's for safety reasons during shipping. A large heavy pack like that is very dangerous because the amount of energy they store. They even leave the chemistry in a more sleep like state to keep the level of energy down. Which means these packs have to be cycled 10 to 12 times to come up to spec. That's also why you only see these sizes of packs in 15 to 35c max.
These packs fit fine in big monos and cats. I have one customer who bought several of my 16,000 mah packs for his boats.
I would also like to add these packs are not for saw use but are great for sport boaters looking for more run time without all the hassle of using twice the number of packs.

Mark

[keithbradley]

It's basic science. Less wire,connectors and cells. What's not to understand.

This statement doesn't make any sense. Perhaps I'm reading it wrong. Do you mean shorter wires? Less wire is certainly not synonymous with lower resistance.

I'm not looking for an argument here, just some clarification. I didn't expect a condescending (non)answer though. Are you considering the wires from the packs to the ESC? I realize that higher capacity cells typically offer lower resistance than similar cells of lower capacity, but in this case we are assuming the same cumulative capacity.

[jkr]

I believe Mark says from 2p to 1p setup.

[MarkF]

Sorry Keith

I wasn't trying to be condescending. 2p versus 1 p is correct. 10s - 10,000 mah made from 4 - 5s- 5000 mah packs or from 2 - 5s 10,000 packs. Less wire is not really for lower IR but for the esc sake. Less wire is always better for any system and less connectors is too. I know running 2 packs is how we have always done it and that's not a bad thing (except when you plug your bullets into the wrong place) but we never had these larger packs before and if for nothing else they make life easier for sport boaters and when plugging into your esc.

Mark

[Brushless55]

Wouldn't you assume a greater total resistance at the plugs compared to (2) 5000mah packs, since you have half the amount of wire connecting to your ESC?

EDIT: I do think the single 10,000mah pack would be simpler, easier if you have plenty of room...just wondering the science behind the above statement.

I wonder what kind of bullets we would need to handle the bigger amp load when running 10,000mah 1P ?
I know when I run my PMono 4s2p 10,000mah my connectors stay fairly cool