The last I looked at this post was towards the end of June when it had 3 or 4 replies. Today I was looking for something & it came up in a Google search with about 10 more replies so I decided I should provide more information. If anybody thinks I should start a new thread let me know. For now this what I know.
Months ago when I bought my 1st bamboo battery it was to test it & then take it apart. Long story short over a 2 month period I bought about 18 more of them. I did a lot of testing & built 3 36 volt bikes & 2 48 volt bikes. 1 48 volt is sold with a 48 volt sla charger. Another 48 volt is in my shop along with 2 36 volt bikes. I'm currently testing the 48 volt bike & charging it with a 58.4 volt LiFeP04 smart charger from battery space.
I will also start charging it with a 48 volt SLA charger from E-BikeKit in another week or so to see how they compare performance wise. I'm using a Watts-Up meter & a Bell Dashboard 100 cyclometer for gathering data. I have not made any provisions for testing individual cells & that is my single biggest concern with these 12 volt Bamboo Batteries. Will these be any good in the long run? Can they be made to last just by monitoring the whole pack? In the short term they seem to be great.
dumbass wrote:There are a few companies that sell similar 12v lifepo4 packs that also do not have a BMS. I have several of the old Thunder Sky and others. From my experience if you charge these packs without a method to balance the individual cells it will come out of balance very quickly. And without a low cell cutoff you will kill the pack. To me this is a bigger issue then the type of charger that is used.
I would love to know the dementions of the cells without the bambo box around it. And what type of cells are actually in the box. Maybe without the bambo boxes there might be room in the stock Currie battery box to also fit a small BMS.
OK then,... this is what a 12 volt 10 amp LiFeP04 SLA replacement battery by Clean Republic looks like on the inside. I was hoping someone else would have done this by now. For now it is neatly cut open & I can put it back together & continue using it. I'm sure someone out there can identify these cellls with out me tearing the whole thing apart. Here is the nitty gritty.
Inside dimension of the box is 2 5/16" W x 5 1/2" L x 3 7/8" H. There is a 1/4" space between the end of the battery & the case at 1 end.
Each cell measures 1 1/8" x 2 1/2" L. . Unless there is an empty spot inside, there is room for exactly 12 of these cells. The voltage is 14.27 & the total weight of the battery is 2lb 9 oz.
My 48 volt bike at the moment is running 5 of these. Hot of the charger the Watts up meter reads 68.88 volts. 30 minuets of normal running brings them down to 64.35 volts. In that condition if I open it up from a standstill on an uphill grade (no pedaling) it will just hit 22 amps & dip to 58.82 volts by the time it hits 22 mph uphill it goes to 20 amps & 61.44 volts. When I hit the leval I'm doing 25 at 7 amps & back to 64. volts. To charge my 5 battery bike I use the 58.4 volt LiFeP04 smart charger from battery space & a 14.8 volt LiFeP04 charge from C.R. (the one that comes with the battery)
Keep in mind that C.R. is selling these as a SLA replacement battery so it's quite possible they may last a very long time in that type of application.
The only comparison testing I've done has been a seat-of-the-pants test using the above bike with one battery removed & an identical 48 v E-BikeKit using a 48 v 9 amp SLA battery pack.
The results?.... Their is HUGE difference in the first 60 seconds & it gets progressively worse pretty quick.
I have pictures of the bike on my blog at:http://ezgo-now.com/local-sales/night-r ... rk-or-play
. I'll try to update this or start a new thread as I learn more about these batteries. For now about the only advice I can give on the charges is if you use an SLA charger of any type unplug it as soon as you think the battery is charged. I use a $10 110 volt timer & set it for how long it needs to be on. You won't know that until you charge it a few times. My 48 volt 10 amp LiFeP04 will take about 2 hrs to charge after I have put about 2 hrs on the clock with the SLA charger. The LiFeP04 charger is faster.