swap lifepo4 for lipo (golf trollies)

[jimmyhackers]

ive been making golf trolley batteries for my dads golfing mates out of (2000mah) 18650 lipo cells. essentially 3s lipos as replacements, either an 3s4p (18 hole) or a 3s8p (36hole)

my batteries work fine in other trollies with lead acid or lipo controllers so this isnt a "my batteries don't have enough Ah issue".

annoyingly older powakaddy trollies use a 4s lifepo4 battery. meaning one of my fully charged lipos shows "low" on the trolley charge indicator from the start then about 13 holes into the course the low voltage cutout appears to be tripping despite the new battery still being good to go.

i see i have a few options
1. buy larger capacity lipo 18650s at great expense and hope the extra amp hours will make it round the 18 holes.
2. buy lifepo4 18650 cells at great expense then turn them into 4s.
3. use my existing stock of 2000mah lipos but adapt the batteries to 4s
4. any better ideas you guys have

im feeling option 3 as i have the parts so i dont have to wait for snail mail and its the least cost to me.
however i would like to ask if anyone knows if a 4s lipo batteries voltage will do any damage to a powakaddy controller??
if it is ok, i know the power gauge will show full almost constantly making it redundant but that is ok/acceptable.

thanks in advance for the advice
jim

 

[amberwolf]

Options:

1--Look at the components of the controller/etc and see if they are all capable of the higher fully-charged voltage. Capacitors are marked, most of the other stuff you'll have to look up their spec sheets. Keep in mind it's possible (though unlikely) that the controller has an HVC preventing operation above a certain voltage.

or

2--use the higher voltage setup but don't fully charge them. You'd have to use more cells to make up for the capacity difference.


In either case you'd want to add a new LVC that shuts them off when the new cells get down to their bottom end, or else you'll end up way over discharging them, with varying results depending on the cell specs and quality, etc.

 

[jimmyhackers]

thanks for the info.

ive been researching myself (reading every manual for every trolley powakaddy does)

it appears all are sold with the option of a lead battery or a lithium one. however annoyingly only one of the manuals describes how to change the battery type between lifepo4 or lead in the controller settings.

apparently plugging in the battery while holding the power button down brings you into an "advanced menu"

hopefully there is something like this on all their trollies (and its been omitted from the manual for "reasons") and i can just change some settings.

failing that there appears to be a hvc of 17v +/-0.5v meaning a 4s charged to 4.1v per cell should be fine. thanks for that idea dude!!

 

[amberwolf]

You're welcome. I'm using exactly that (4s NMC at 4.1V, for 16.4v total) as my "12v" lighting system battery, on both my CrazyBike2 and SB Cruiser. Most automotive stuff tolerates this just fine.

But not everything does, so that's why I suggested checking the parts in the controller/etc. However, if it has a 17v+ HVC, that implies all the parts in there can handle that so you should be ok.

 

[jimmyhackers]

turns out they were both motocaddies.

annoyingly it appears both the motocaddy m1 pro and the motocaddy S1 have omitted a change battery voltage function

not too happy

looks like im making some 4s batteries