OK. Say I got these (2x 18.5v 4000mah) [http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=270343671340] and these (2x PCM cards) [http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=350162861612] . Then maybe this charger [http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=110299153505] and one of these (lipo fire bag) [http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=290294847571] . I know this is not the greatest stuff. Can't afford the greatest.
Will this work out for me? I will be looking at a 40A max scooter controller in a Razor Pocket Rocket. Want to go fast and not that far.
Thanks in advance.
The PCM cards don't match the packs. They're rated only for 14.x volts while the packs are 18.5 volts.
I've never used the LiPO packs but this looks marginal. That is, you're expecting a 40A use rate and the packs are rated for 60A (15C) max discharge. That fits however my personal philosophy is to always have plenty of excess rated capacity. e.g. if you're continually pushing a battery to its full rated capacity that is usually damaging. In general a particular instance of a gizmo might not meet the specs, because when a manufacturer gives specified ratings for gizmos it's always stated as a range. A given battery might produce slightly less and still be within the range of the manufacturer ratings.
In years past plenty of people had lots of fun using B&B SLA batteries on pocket bikes.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Thanks. I posted the wrong PCM card link.
Yep, I had a little experiment with these recently. They good & are great value. Also Lipo does have some advantages over LiFePO4 - higher cell voltage and higher discharge C's. One thing dont short them out lol!
Personally I wouldnt bother with a battery management card,
Tip Ive worked out is u can charge these packs in parallel on the normal Lipo charge, Just Clip the crodile clips on all the negs and pos of the batts at once. Dont bother with the Lipo Balance charge option!
Im prefering now the 2 or 3cell packs (7.4 or 11.1v) rather than the 5 cell ones - and then have 3 packs in series rather than two. Reason is gives less need for cell balancing hassle as more parallel than series charging!
Ive seen some 11.4v 8000mah ones at around $40 each . Three of these in series would give approx 36v 8ahr pack. Bigger range and better max amps (15x8=120 !!!)
http://cgi.ebay.com/RC-Lab-8000mah-11-1v-15c-Li-Po-Li-polymer-Battery-Akku_W0QQitemZ160315669036QQcmdZViewItemQQptZRadio_Control...
Extending this logic - I think batteries would be better havimng all their cells charged in parallel rather than bothering with irritating BMS cicuit boards. No reason why it cant be done. I see the future of 36v LifePO4s being charged at 4v (all cells in parallel). Just need a nice switching mechanism to change from series use to parallel charging!
Love those 8A cells. I was mostly thinking of the BMS to avoid thermal runaway while driving. Crashing is one thing, catching on FIRE and crashing is another. My biggest concern is just overtaxing the batteries. I want to dump a LOT of amps for hard take-offs. May also use this pack and a higher amp controller in a MX500.
Nahh, forget the BMS - boring!
Anyway these packs burn internally when they r crushed. A BMS wouldnt stop that. The fires Ive had havent been serious,a few puffs of smoke and a small flame at worst. I was hoping for something more exciting lol. I even drilled one pack to create my own 'Exploding Lipo pack' Youtube video but it did nothing more than a few sparks!
8000mah Lipo could def give enough amps to run ur MX500
I could use a monitor to keep a eye on undervolting and put them in a aluminum box. :-D. Maybe i'll pick up one pack to see if it can take the rated charge.
I like Exploding Lipo pack video idea. HeHe!