9 S balanced battery charger

[team death]

I bought some 9 s lipo batteries but I can't seem to source a charger for them, any clues?-there are two

balance wires sticking out of them so I assume both must be plugged in?.

[Ocracoke]

Given the two balance plugs, are these really one battery unit and not a 4S and 5S wired in series? Do you have a picture of the balance plugs?

[team death]

Hi Lucy, very good question- all I know is my charger just doesn't want to know when I plug the balance wire in to
the correct slot on my 1 to 6 S charger-the voltage is just too high 33 volts plus.
when I tried plugging both balance wires in sparks flew but luckily I was quick to pull it out-but you are right one connector
is a 4 S and one a 5 S.
I'm now thinking I made a mistake buying them as the chargers available are well over £100.

[Shakey]

Given the two balance plugs, are these really one battery unit and not a 4S and 5S wired in series? Do you have a picture of the balance plugs?

All the LiPo's we use are just a series of cells. The S describes how many of them there are. A 9S LiPo is just 9 cells in series so a 4S+5S and a 9S are exactly the same. This is just an awkward arrangement of balance connectors.

Often these kinds of batteries split the balance port in order to allow use with more common chargers which typically stop at 6S however if there's only 1 plug then you'd only be able to charge through the balance port alone.

Hi Lucy, very good question- all I know is my charger just doesn't want to know when I plug the balance wire in to
the correct slot on my 1 to 6 S charger-the voltage is just too high 33 volts plus.
when I tried plugging both balance wires in sparks flew but luckily I was quick to pull it out-but you are right one connector
is a 4 S and one a 5 S.
I'm now thinking I made a mistake buying them as the chargers available are well over £100.

It's important to be super careful when handling packs like this. What you described was shorting the battery to itself through the balance connectors. Inside the charger all the plugs are normally commoned internally with the other plugs. So plugging both connectors in is will short the cells from the first half of the pack to the second. You CANNOT plug both balance leads into 99% of chargers like that.

The charger is unhappy as I imagine from the 33V reading you have the main connector plugged in? In essence you are plugging in a 9S battery (beyond it's capability) but only giving it access to 4 or 5 cells for balancing at a time, any charger will be unhappy about this. You may be able to do a balance charge with the main connector unplugged if your charger supports it but it's going to be slow.

Chargers do go up to high cell counts but get pretty pricey. I'd personally recommend changing the battery packs rather than the charger as you'll then have a much more conventional (Therefore easier to work around) setup for future.

Not so important but: Another recommendation would be to bump the cell count up or down one to 8 or 10S so you can split it into a pair of 4S or 5S batteries and have both the same. Nothing wrong with having a mixed set but it's easier at events to deal with batteries when they are all the same.

[team death]

Hi Alex

Thanks for all that information and I think you're right about advising sticking to lower voltage batteries

rather than a new charger.

On bumping the cell count up or down I'm very interested -Is this normal practice? and is it relatively easy to do?

perhaps when a cell is down beyond recall ?.

[Shakey]

Hi Alex

Thanks for all that information and I think you're right about advising sticking to lower voltage batteries

rather than a new charger.

On bumping the cell count up or down I'm very interested -Is this normal practice? and is it relatively easy to do?

perhaps when a cell is down beyond recall ?.

I just mean rather than running the robot on 9S you run it on 8S or 10S so you can buy 2 matching smaller batteries (2 4S or 5S rather than mixing a 4S and 5S). Just makes it a bit easier to deal with.

[team death]

Oh I see now, I thought I was missing some kind of Hack .
Yes I can run it on 2 x 4 S no problem just need to lose 300 gram somewhere.

[Redirect Left]

Hi Colin,
I used to have an up to 10S charger, and that cost nearly £200 to give an idea of how much those can cost, compared to chargers for 2-6s which can be purchased for under £50 from reputable sellers such as HobbyKing. Just for sake of keeping on the right side of the bank, I'd definitely also recommend going down on cell counts on batteries, and bumping them up running more than 1 battery as we've done before on Mean Machine, using 2x4s (if i recall correctly, or was it 1 battery per motor? it's going back a while now!).
It's good to see you're comitted to LiPos, after i introduced you to them back in the early Mean Machine days, and they seemed to impress you nearly immediately, as i recall.

[team death]

Hi Adam
Long time no see.
I bought 2 9 S batteries thinking the two balance wires would mean I could charge up the 4 cell then
the 5 cell separately without the need to upgrade the charger but I was wrong and have resigned myself
to run off 2 4 s batteries instead.
I had great performance from the 9 s I used, but without the ability to charge it,it just faded through
the day and was sluggish and only showing 20 volt so I may have damaged it beyond repair,though the
casing is not bloated.
Compared to the old Gel batteries the Lipos are amazing so I will always be grateful for your input on
those and speed controllers and LED usage.
Things are back into full swing at Dojo so come to an event or for a repair session if you feel like it.

[Redirect Left]

Things are back into full swing at Dojo so come to an event or for a repair session if you feel like it.

Unfortunately I no longer have a vehicle, I sold it to a friend during the pandemic, as i was at that point paying about £1.75k a year for a car that went no where, and they needed one for their job. So it's a little difficult at present to get up to Dojo, I'll be looking at getting another one though when everything has calmed down and i'm unlikely to have it sat doing nothing again, though.

[team death]

I know young drivers get hammered with the insurance -due to Boy Racers pushing up the premiums I think
and of course there is MOT and maintenance costs not to mention fuel.
As an idea if you want to store your robots up here you could bring them up and I can get them match ready
so you could attend a Dojo by train and bus.

[Redirect Left]

so you could attend a Dojo by train and bus.

Unfortunately, on Sundays, the first train from Wakefield doesn't arrive in York until 09:47, then the time (and cost) of an Uber to Dojo, shame it isn't on Saturdays, first train is 06:23 arriving at York then. Unfortunately Sundays is very inconvenient at that location for any methods of public transport (other than a really expensive Uber the whole route, to get there on time for start). I'm hoping insurance goes down later in Feb when the anniversary of me passing the test goes up to 3 years, and i can be back at events soon enough. It was a rather pleasant drive from me to Dojo, nice bit of motorway and then countryside roads after that around & up York.

[team death]

No worries

Dojo doesn't tend to get started until 10.30 for most events but you attend in your own time

mate and by whatever transport method suits, for now I'm getting on with driller King to go

with my queen.