Upgrading a go-ped esr to lipo

[mr.electric]

I just started the process of upgrading a go-ped esr 750 from lead to lipo. the scooter belongs to extreme green machine. He ordered two 6s 8ah zippy packs, two cell logs and has a Hyperion 6s charger. I installed a pack. The scooter rides well with one pack even though the supply voltage is a bit low. 7s would be better. I charge the packs with the Hyperion and run with the cell log installed. The scooter has a built in 24v charger which would be very cool to use for convenience. Could I use the alarm signal from the cell log to run a relay that would disconnect the charger once one cell hits hvc?
I am guessing this is the approach developed in other threads that mention the cell log based balancer but I do not find a complete circuit that interfaces with cell log to use the alarm signal to interface with charger for hvc and controller brake signal for lvc.

 

[scoot]

her ya' go. pic by walls99



Not sure if will interrupt the charge when HVC activates but I have verified the discharge LVC side of things and it seems to work.

 

[mr.electric]

Thanks for that valuable information!
I think a full BMW is unnessacary since these are 30c packs. I just need to get hvc set up using the cell log alarm signal. How does the goodrum cell log based bms work. I have seen it mentioned but cannot find a finished board or bom.

 

[scoot]

When you find out about where/who precisely, LMK, lol. I haven't been following the progress on that project as of late. I am very intrigued about the possibilities and am just waiting for the oportunity to try it out myself. Right now I am using a DB8 balancer in conjunction with the onboard charger and controller using 8s Life cells. It seems to interact nice enough (cell based HVC too), but not sure how well the on board components would play nicely with this device and 6s lipo. I suspect the Celllog integrated Goodrum devices will be better suited for both of us in the end. 8)

 

[scoot]

I thought since you'll probably get around to inquiring, this where you'll want to connect up between the onboard charger and controller if end up going with a bona-fide HVC circuit of some kind. Basically you splice in your HVC capable device of choice into the red and green wires of the 4 wire interconnect harness between the charger and controller. For newer models (2008 and newer) the green wire is (-) and the red (+). This seems to be the reverse (polarity) for some older models.

Another thing you'll want to know, if you don't already, is that a CellLog attached to a pack system for long term will knock your pack out of balance due to preferential draining of one or more channel over another to keep power to the CellLog. i forget which channel(s) though. That's one of the many features of the Goodrum/Fetcher CellLog based units are designed to deal with I believe.

 

[mr.electric]

Ok I see that you have made a workable hvc using off the shelf components. What is the balancer you use doing? It only has two wires in and two out so I imagine it just keeps the total pack voltage under a certain preset then disconnects?
If I could get a good hvc and lvc set up I would most definitely add another lipo cell and go to 7s.

 

[mr.electric]

This balancer works during charging, reads individual cells for hvc. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7443
I guess you have a similar product in play Scoot.
This may work for me too. I could use the cell log for lvc and this balancer for charge balance and hvc. I only wonder if this balancer and the cell log may be connected simultaneously.
I checked out tppacks' offerings and see a full balancer, parallel and hvc board and associated hardware for sale. The tppacks hvc also incorporates a parallel set up which I would not need since I am only running 6 or 7 s 1p.
I guess the cell log balancer has been superseded with the full balancer or parallel circuit.

 

[scoot]

heehee... as I was replying to your earlier reply you posted yet again LOL anyway this was what i was going to post:

You got it mostly. There is also a 8s 9 wire balance port for the cells (you can use 7s or less on it). It gently balances the pack in a float charging mode and the HVC is actively regulating the current through the wires shown in the pic. But in my case it is 8s Life. I haven't tried 7s lipo either, but suspect it might play nice too. Cell based LVC as a function of active control is not a feature on this device... only a barely audible beeping alarm for LVC. But, I have been given an idea from a compadre to see if it can be modified to achieve the LVC function via the ebrake pads on the controller. Sort of like the celllog Wish i could solder worth a darn.

 

[scoot]

Yep the TP kits are cool... now to find out again who is assembling any I can get

 

[wineboyrider]

geoff57 is the one that's selling them. There is a thread in the for sale section. Tell him wineboyrider sent ya. 8)

 

[mr.electric]

The lvc hvc circuit is available soon. I still wonder about the unfinished cell log based bms. I will post my super simple circuit idea in another thread.

 

[mr.electric]

I connected he cell log alarm output to the brake input of the goped esr. I had an interesting result. The scooter does not run with the cell log connected with a full 6s battery. Disconnect the cell log and it runs. I switched the cell log from n.o. to n.c. alarm output just to see but it still seems to constantly short the brake wires. I even tried another brand new cell log, same result. I tested the alarm output of the cell log and got interesting results-
With my meter on the beep tone continuity test it beeps wether the alarm is n.o. or n.c. with a full charged 6s pack connected. When I test with my meter on the lowest scale (200ohms) it shows the circuit open when it should be open (full battery and alarm output set to n.o.)and closed when it should be closed (full battery and alarm output set to n.c.) Does too much voltage on the alarm output wires overpower the circuit and make the cell log short the alarm output wires at all times?

 

[scoot]

Try checking/setting the total pack voltage limit and the cell voltage limits. As I recall, either one will affect the cellLog alarm trigger. I can't think of anything else to try :|

 

[mr.electric]

I'll check the setting.