Help with Lithium smartcharger for IMR 26650

[sterr11]

I am trying to expand beyond using my WF-139 for charging muliple IMR 26650, both because of the awkwardness of trying to make them fit into the charger and the length of time it takes to charge. I purchased this
http://www.batteryspace.com/smartch...eablebatterypackstandardfemaletamiyaplug.aspx
on the recommendation of the batteryspace salesman, but it will not work on a single battery. It always cuts off before the cell is charged and sometimes will not charge at all after being on the charger for an hour. On further investigation of the specs of the charger, it appears to work on packs of greater than 5A. Batteryspace does not appear to be return friendly, in fact their RMA page is broken art the moment.

My question is can I rig up some way to make this charger charge multiple (3 or 4) batteries at once, which is apparently what it was designed for. Can I simply parallel 3 or 4 IMR 26650 and safely charge them, or it something else required to balance them.

If this charger is no good, what should I purchase?

 

[pae77]

I'm not really familiar with that charger that you got but it looks to be rather limited, especially for the price.

Imo, for Li-ion batteries, an inexpensive hobby charger like the Accucell 6, to name one possible example, is a great and flexible way to go. I am not necessarily recommending the linked to vendor as the best place to purchase one, although I believe they are among the cheapest, but they are located in China and if you need to return the unit for warranty exchange or service, the costs and time involved in doing that will negate the cost advantage of buying from them, imo. There are also some US based retailers that sell these units, frequently for just a few dollars more than Hobby King after the cost of shipping is included, and I used one of those to get mine, which turned out to be a good thing as I needed to do an exchange of the first unit I received, which proved to be quick, easy and inexpensive.

Anyway, it's a snap to use some small rare earth magnets to hook the positive and negative leads of the cable the charger comes supplied with up to a single cylindrical cell and you can choose any charge current from .1 amps (i.e., 100 ma) to 5 amps as may be appropriate for the capacity of the cell you are trying to charge.

You will need a separate power supply for this type of charger, unless you pay more for a unit that accepts AC as well as DC power sources. The Accucell 6 accepts DC input voltages of 10 to 18 volts. I'm using a 16 volt 4.5 amp old laptop power supply that plugs right in to the input jack on the charger. There are 12 volt 5 amp power supplies available cheap on ebay if you don't already have something appropriate lying around.

Another neat thing about these chargers is that on the charger's display you can see the charging current, voltage and ma's the charger has pushed into the cell in real time as the cell is charging. And the charger beeps to let you know when the battery is full and, of course, really cuts off the current, i.e., does not trickle charge after the cycle is complete.

Anyway, that's my suggestion. I'm real happy with mine and feel it's much better than the real cheap cradle chargers that in most, if not all cases, don't really use a proper CC/CV algorithm for charging Li-ion cells, and of course are limited to one set starting charging current, and many of which are prone to over charging or trickle charging which is not good for Li-ion cells.

 

[roadie]

if u wan a cheap and gd charger , u may wish to try this ....

Cellpro Mulit 4

Cellpro 4s
( i got the older version of this, :thumbsup

since my 4s requires a minial of serial of 2 batteries, i always try to use suitable battery holders and wire them up ... not really too difficult, jus follow the manual ....

the newer multi 4 chargers nimh and sla and of course, li ions .....

happy shopping

 

[alpg88]

I am trying to expand beyond using my WF-139 for charging muliple IMR 26650, both because of the awkwardness of trying to make them fit into the charger and the length of time it takes to charge. I purchased this
http://www.batteryspace.com/smartch...eablebatterypackstandardfemaletamiyaplug.aspx
on the recommendation of the batteryspace salesman, but it will not work on a single battery. It always cuts off before the cell is charged and sometimes will not charge at all after being on the charger for an hour. On further investigation of the specs of the charger, it appears to work on packs of greater than 5A. Batteryspace does not appear to be return friendly, in fact their RMA page is broken art the moment.

My question is can I rig up some way to make this charger charge multiple (3 or 4) batteries at once, which is apparently what it was designed for. Can I simply parallel 3 or 4 IMR 26650 and safely charge them, or it something else required to balance them.

If this charger is no good, what should I purchase?

it might, at 3 amp current it might not work on small capacity cells,
you can definitely parallel at least 2, every laptop has 2 in parallel

i use smaller 1,5 A charger with 26650 and 32650, from them, works great, actually i got 2, cheaper, and simpler than messing with balance circuit.

btw, in your item discription it says
Designed for charging 3.6 V ( 3.7V Nominal) Li-Ion and Polymer Li-Ion battery pack with capacity > 5000 mAh

26650 are 4000mah

 

[sterr11]

Thanks for the suggestions. I have sent the batterystation charger back, and will try one of those suggested. All look to be much better chargers for about the same or very little more money.