Hi RC Tech land,
Very new to this world of RC & if you like got into it rather big way too quickly
Just purchased a B44 second hand RC buggy
It has 2 Venom LIPO saddle batteries & really struggling to charge them
Batteries are venom power 7.4V 5000mah 35c 2s2p
Battery charger is HiTech X1 unit
I connect batteries together with included balance lead - connect red charger lead to + on battery - connect black to - on second battery - connect loop lead with balance plug from - on first battery to + on second
Set charger to 5.0A - 7.4v (2S)
Charger comes up "cell error voltage invalid"
Did some goggling & tried combinations of following
10.0A - 7.4v (2s) / 5.0A - 14.8 (4S) / 10.0A - 14.8 (4S)
Even flipped around the loop lead - Still no success - what am I doing wrong as I have not been able to test the new buggy let alone use
Some might be laughing I know but I need HELP

If it comes to it, you can just charge them each separately as a 1s battery.

You shouldn't try to charge them like that. The way you have them hooked up is in series. Unhook the leads and hook it to single battery. Positive to positive and negative to negative. Make sure the balance lead is plugged in and hooked to charger.
You will charge at 5 amps @ 7.4 volts.

Just to verify, each battery says this on the label right??
Batteries are venom power 7.4V 5000mah 35c 2s2p

Appreciate the advise there
CORRECT that is what is says on the batteries
Not to sound overly dumb here but if they are not meant to be hooked up together for charging why does the charging leads have three wires + & - & balance plug joined onto loop lead ?
The batteries only have + & - connection points on them, they are not like my other LIPO sticks for both SC trucks with a small earth connection in between the + & - with balance plug already connected

You appear to be on the right track. 5.0A - 7.4v (2S) is the correct setting.

Does the balance connector from the battery have 3 wires, including to the main positive and negative? Something like this?



Are the batteries also used? Do you have any way to check the voltages? Each saddle should be between 3.0V and 4.2V. If lower than 3V most chargers will refuse to charge because of possible damage to the cell and thus a safety concern. (Actually it should be even higher for a good cell at rest, at least 3.6~3.7V or so)

Every 2S saddle pack I have seen is wired in series. Each saddle is a 1S. Very common to charge them as a series pack, most come with such an adapter. A quick search of Venom info suggests they are the same.

As Panda mentioned it is possible to charge each saddle separately, or together in a parallel hookup, but the charger needs to be set for 1S 3.7V.

Good grief, these are 2S packs, not 1S. Each 2S battery needs to be charged individually, not in series. Fact of the matter is, he should be glad the charger wouldn't charge them in series, bad stuff happens with mistakes like that. It's apparent me and you don't see eye to eye on much, but go ahead and tell him to charge them in series. It can be done, but I would make sure they are outside so they won't catch anything on fire.

This is the lead he needs to charge each pack individually. With whatever end he needs, Traxxas or whatever.

Here are a few images of 2S saddle pack wiring. Including one with the charger set as a 2S. The 1S bricks are are wired in series to create a 2S pack. Only one jumper wire between the pack to create the series connection.

If each brick was a 2S, the pack would need to be wired in parallel. Would require both positive and negative leads from the connector to each brick. If they were 2S bricks they would each need a place to put the small intermediate balance plug, like a standard 2S pack.

Since he is obviously a noob, I would suggest charging each 2S pack individually. Later on when you get more comfortable charging, you can jump to multi pack charging.

I assume this is what you have, just named Venom
http://www.ebay.com.au/itm/Lot-of-2-...-/400601695863

If 2s saddle packs are not supposed to be charged in series then why do manufacturers supply a lead that does exactly that. They are run in series as well so why would they need to be charged in parralel ?
The problem is the fact that they are USED batteries and very likely are way out of balance which is what gives the invalid error message. I am not familiar with the x1 but you should be able to see the individual cell voltage, check to see what they read and let us know. Also, simply charge them without the balance lead, do a fast charge. Do a discharge, recharge, cycle them a couple times and the low cell may come back enough to charge with balance.

umm, so how do you charge a 2s stick pack ? open the plastic case and do each cell then tape the case back together ? That is what you are proposing.

uh ? each saddle is a 2s ? Saddles are two individual 1s packs designed to be used in series.

you sir are not dumb, that is correct. You just have one cell that is too low to take a balance charge.

Charge them individually as 1s packs. Bring them to the same voltage. Then in the future you should be able to balance charge them.

For a newby, keep it simple for now!!!