LiPo batteries

[Chegs]

How did you get on with these Lipo's @Chegs ?

Are they easy to solder together ? and did you use any fuses?

I bought 10 of the 1000 mAh cells,and also bought 10 of the 2200 mAh cells.The 10 smaller cells,with me constantly experimenting with various configurations suffered "contact failures" as the little metal tabs are quite fragile and eventually broke away so I've only got 6 still usable and 4 are in a mates mod.

I now make a small square of fibreglass which I cut slots in to hold the contacts,arranged so that with the cells taped together in a block the fibreglass sits across the top of the cells and then just bend the cell contacts flat to join the next cell.Quick dab of solder then secures them electrically and reduces any strain on the fragile contact.

I didn't use any fuses,though have since discovered that in the event of a dead short the mosfet fails and therefore I've never had a lipo get any stress.

To recharge the lipo packs,I've also now purchased a balance charger.This can recharge even a 6600 mAh pack in under an hour,whereas the little USB boards were taking upwards of 8 hours to recharge a 4000 mAh pack.

 

[adjam1972]

I bought 10 of the 1000 mAh cells,and also bought 10 of the 2200 mAh cells.The 10 smaller cells,with me constantly experimenting with various configurations suffered "contact failures" as the little metal tabs are quite fragile and eventually broke away so I've only got 6 still usable and 4 are in a mates mod.

I now make a small square of fibreglass which I cut slots in to hold the contacts,arranged so that with the cells taped together in a block the fibreglass sits across the top of the cells and then just bend the cell contacts flat to join the next cell.Quick dab of solder then secures them electrically and reduces any strain on the fragile contact.

I didn't use any fuses,though have since discovered that in the event of a dead short the mosfet fails and therefore I've never had a lipo get any stress.

To recharge the lipo packs,I've also now purchased a balance charger.This can recharge even a 6600 mAh pack in under an hour,whereas the little USB boards were taking upwards of 8 hours to recharge a 4000 mAh pack.

Cheers for the reply . Very helpful.

Am currently trying to decide which route to go down with my first Hammond build, dual 18650, dual 26650 or 4 1000 mah lipo

decisions decisions

 

[adjam1972]

I bought 10 of the 1000 mAh cells,and also bought 10 of the 2200 mAh cells.The 10 smaller cells,with me constantly experimenting with various configurations suffered "contact failures" as the little metal tabs are quite fragile and eventually broke away so I've only got 6 still usable and 4 are in a mates mod.

I now make a small square of fibreglass which I cut slots in to hold the contacts,arranged so that with the cells taped together in a block the fibreglass sits across the top of the cells and then just bend the cell contacts flat to join the next cell.Quick dab of solder then secures them electrically and reduces any strain on the fragile contact.

I didn't use any fuses,though have since discovered that in the event of a dead short the mosfet fails and therefore I've never had a lipo get any stress.

To recharge the lipo packs,I've also now purchased a balance charger.This can recharge even a 6600 mAh pack in under an hour,whereas the little USB boards were taking upwards of 8 hours to recharge a 4000 mAh pack.

@Chegs

picking up on your charger comments. So do the small usb 1amp
charger boards (TP4056 1A USB Battery Charging Module Charger Board (short)) work ok to charge 4 lipo's in parallel (apart from the time required) or is a balance charger required with lipo's

 

[Chegs]

@Chegs

picking up on your charger comments. So do the small usb 1amp
charger boards (TP4056 1A USB Battery Charging Module Charger Board (short)) work ok to charge 4 lipo's in parallel (apart from the time required) or is a balance charger required with lipo's

The USB chargers do work,but because of the huge amounts of stored energy in a lipo it is a risky way to charge them.The risks are entirely up to the user,as the USB boards I have sometimes decide that the lipo hasn't reached their cut-off voltage and remains charging for hours(or would if I didn't disconnect them and check them on a volt meter)I always handle these type of battery with the utmost respect.After the 2nd time of discovering the USB board wasn't ceasing to charge I bought the iMax Balance charger and replaced the USB port with an JST socket(think that's their name)The Balance charger refuses to charge the cells if they're to far discharged so I occasionally have to take the pack apart & try charging each cell alone,and if the cell is too discharged on its own,THEN I'll use the USB charger on a cell for 1 hour.Then rebuild the pack,and recharge the pack on the balance charger(usually only needs connecting up before the charger bleeps to confirm they're charged)I am presently investigating where/what type of balance charging leads & plugs I'll need buy to add these to my packs,as the bare lipo cells are cheap but the exact same ready-built packs seem expensive for essentially what appears to be a few pieces of wire & a couple of plastic plugs.

 

[adjam1972]

Chegs thanks for the info. I suspected that it wouldn't be as easy as I was hoping. Shame really as the cost of lipo's is so good. Think I'll stick to good old 18650's and 26650's for now.