5s question???

[frdvschvy]

I do not know much about lipos but have previosly been running two 2s 5400 MAH packs in series with my stock BJ ESC and motor. One of my 2s packs discharged completely in storage and I cannot revive it. Could I purchase a 3s pack and run it in combination with my 2s pack for a total of 5s? Do I still run them in series? Do I need to get a 3s pack that is the same MAH and discharge rates as my 2s?

Is this even possible or am I way off in my thinking?

Thanks!

[Ub Hauled]

get the same "C" rate and same mAh, and you'll be able to run it in series no problems.

[sn00p]

i run 5s via 1 x 2s and 1 x 3s 4900mah zippy rhino packs. I built an add-on weight for the 2s pack to balance the hull out simply with bluetac. Read some of my threads regarding the stock ESC not liking 5s and x642 prop whilst attached to the bec with the timing set to high... you may want to pull the red wire and run a seperate RX to be on the safe side. OR keep timing set to low and be careful with prop selection.

[frdvschvy]

i run 5s via 1 x 2s and 1 x 3s 4900mah zippy rhino packs. I built an add-on weight for the 2s pack to balance the hull out simply with bluetac. Read some of my threads regarding the stock ESC not liking 5s and x642 prop whilst attached to the bec with the timing set to high... you may want to pull the red wire and run a seperate RX to be on the safe side. OR keep timing set to low and be careful with prop selection.

Will the boat be substantially faster with 5s even with the motor timing set to low and a smaller prop? Last thing I want to do is spend the money if I don't have to. Would I be better off to just run 4s with high motor timing and an X642?

[785boats]

frdvshvy
There is a possibility of reviving that discharged pack if it is not puffed.

Only do this if you feel confident & only with the pack in a Lipo sack.

Firstly put it on your balancer to balance the cells at whatever voltage is in the lowest cell. There must be some voltage there.
Next remove the balancer & charge the pack on the "NiCad" setting at ONE amp through the main power leads (not the balance taps) until the voltage reaches 3.0volts/cell.
Keep an eye on the pack at all times & regularly check for temperature.
Any signs of swelling or heat remove from the charger. The pack is no good. Take it outside.
It should only take about 5 min to bring the pack up to 3.0 v./cell
When the charge voltage reaches 3.0v/cell remove from the charger.
Check the voltage of each cell & rebalance if required.
Let the battery sit for 5 min then place on the normal Lipo charge.
Keep it in the sack & check regularly.
When finished check the voltage of each cell & write them down. Check again a few hours later & again the next day.
If the voltage of one of the cells is falling then it's faulty.
Discharge under controlled supervision for the first time down to about 3.5 v/cell under a light load.
I use an old 700 brushed motor with an 8 x 6 Aircraft prop on it that I know draws 12 Amps on 7.4 V & 24 Amps. on 14.8v for all my testing.
If everything is OK & the cells remain reasonably well ballanced, just recharge as per normal.
Keep a close eye on the pack for the next few cycles.
I'm curious as to why it discharged while it was sitting on the shelf though.
I've brought a pack back from the dead using the above method & it's still going strong.
Any questions, just ask.
All the best.
Paul.

[frdvschvy]

i run 5s via 1 x 2s and 1 x 3s 4900mah zippy rhino packs. I built an add-on weight for the 2s pack to balance the hull out simply with bluetac. Read some of my threads regarding the stock ESC not liking 5s and x642 prop whilst attached to the bec with the timing set to high... you may want to pull the red wire and run a seperate RX to be on the safe side. OR keep timing set to low and be careful with prop selection.

Well, bit the bullet on a new 3s pack. Also picking up a Castle BEC that can handle the voltage so I can bypass the one in the ESC. This should allow me to still run the X642 and high timing correct?

[Ub Hauled]

there is no reason to run a higher timing... it generates a lot of heat.

[sn00p]

Well, bit the bullet on a new 3s pack. Also picking up a Castle BEC that can handle the voltage so I can bypass the one in the ESC. This should allow me to still run the X642 and high timing correct?

Well atleast you will not smoke the ESC via the bec.... as for hi-timing im not 100% if this will help out but i do know other people have got away with 5s and hi timing settings whilst using the ESC bec on x642 props. HOWEVER i smoked mine and advise anyone to remove the onboard bec and like you have done run an external. You are "imo" good to go on 5s and low timing without any issues as long as you use that bec.

Now for the high-timing.......... I never even tried running my boat on the low timing once i bought that programming card so cannot even comment on weither the hi/low timing settings make much difference in speed, But it is common knowledge that having the timing set to high can build up serious heat... SO i would personally run on low timing for a few runs so you know how well your boat runs. then try a few short bursts on the high timing and see if you have any better results. IF you do and thnk its worth the effort then get yourself a temp gun and do short runs getting longer and longer but after each run check for temps on both motor and ESC... Now you see why i was happy to swap out the ESC for that seaking 90a. just saves a whole load of soddin around....Saying that the seaking has 5 timing selections lol but im happy with how it came and will be leaving it there.... another 1 or 2 mph i cant be arsed.