charging lipo in parellel

[vintcs]

Hi, just wondering if i can charge the 2 lipos in parellel?

[Unorthodox_Sniper]

yes you can but not recommended because eg if you want to charge 2 parallel packs of 3S it is very difficult to ensure that all the 6 cells are balanced. While you may save half the charging time there is the risk of overcharging some of the cells and bloat them so it's not worth the time saved. So it is still better to charge the 2 packs individually and always thru a balancer. Or you can use 2 chargers and 2 balancers to charge them separately at the same time.

If you have not started building your parallel packs I recommend that when building the parallel packs you do not solder them together permanently, instead make a parallel connector so that you can separate them after flying in order to charge them separately.

Btw, where in Ubi do you fly? Come join us at bedok reservoir mosque field on weekends mornings

[vintcs]

Is it the open field with fences? thought of going there to test out also...i fly with a friend at defu. Wana try ubi also. PM me your contact. Thanks.

[Unorthodox_Sniper]

yeah it's the open field with fences. I have PM you my contact.

[vintcs]

what if u use the Y-connector to charge the lipo in parallel and attach a lipo balancer on each battery? can work this way? becos i dun charge through the balancer on the battery....

[kennyc]

what if u use the Y-connector to charge the lipo in parallel and attach a lipo balancer on each battery? can work this way? becos i dun charge through the balancer on the battery....

not advisable. coz each pack will peak at its own level.

if you use an amp meter, you can see that the amperage on each connection to each battery pack is different.

[X34]

This issued had being discussed quite extensively on Rcgroups, maybe here as well.

It is possible to charge in parallel for single cells without any problem.

For 2s and more, it can be tricky. The ans is still yes if u know what u are doing.

Scenario1, 2 packs of 3s 2000mah charging at 1c. When u parallel the packs to 3s2p @ 1c would be 4000 mah charge current. If one of the pack develops high resistance, most of the charging current will flow into the other pack and caused overcharging. U will end up with one pack over voltage and one pack under.

Scenario 2, charge the pack in parallel up to 50%(if u are sure that both are fully discharged) disconnected the pack and complete charge in single pack, save about 25% charging time.

Bottomline, it is not worth the trouble. Better off charging the packs in series with proper balancers. Save 50% the time. U will need a charger with high cell count capability.