Ebay Power Meter

[sulley]

Hello all!

I've just finished building my first ebike project, a Cyclone 1680W 3 ring kit onto a hardtail mtb. It's a blast!

My intention was to run it on 2 6S 16Ah lipo packs in series, no BMS, fused at 80A, cell UVP managed using a couple of Hobbyking undervoltage beeper things and pack voltage monitoring provided by the throttle. Charging performed using a balancing charger. Conveniently though, a friend gave me some 5Ah 5S packs, which I'm using at the moment (15s config.) because I'm worried about damaging the new, expensive packs.

Anyway, the point of this post is that I would really like a Cycle Analyst, but at the moment it costs too much for the functionality it provides relevant to me. Basically all I need is a power meter, however, the problem is that when I run the 15s pack the voltage is in excess of 60 volts which writes off all of the remote control power meters found on Hobbyking. However, I've found some alternatives on eBay and wondered if anyone has any experience with any of these devices? If not then I guess I'll post an update in a month when I've received mine!

The one I've purchased:
http://www.ebay.co.uk/itm/100A-DC-Digital-LED-Power-Meter-Monitor-Power-Energy-Voltmeter-Ammeter-Shunt-/321957878300?hash=item4af62f5a1c:g:MUwAAOSwSHZWfKv8

The wireless one which I quite like:
http://www.ebay.co.uk/itm/100A-Digital-Wireless-Voltage-Current-Power-Meter-Time-Ammeter-Voltmeter-CW1H-/321905936561?hash=item4af316c8b1:g:qjsAAOSw14xWMaim


Thanks

 

[motomech]

You need the CA to provide a hard and fast LVC for your Lipo.
A CA is a lot less expensive than Lipo.

How do you balance charge 15S?

 

[sulley]

You need the CA to provide a hard and fast LVC for your Lipo.
A CA is a lot less expensive than Lipo.

How do you balance charge 15S?

Well atm I disconnect the pack and charge each 5S pack separately on a balancing charger, however I have 3 balancers coming which will allow 63V to be applied across the pack, to charge it without dismantling the pack.

TBH, ultimately I probably will get a CA, but this ebike lark is pretty harsh on the wallet, maybe next month. Also it pains me to see the difference between the US and UK prices, and if I import I'll get stung on taxes. Yes... I'm tight!

 

[fechter]

I use a similar meter on my battery charger. The one I have displays Amp-hours, so could be used to track battery capacity.
One drawback is the readings get erased when you power off so the Ahr reading goes back to zero. If you wire it so it stays powered even when the bike is off, you could avoid this, but it would put a small drain on the battery while off.

I like the wireless one. Haven't seen that one before.

Some versions have an 'alarm' feature you can program alarm set points for high/low voltage, current, etc. This could work like a CA.

 

[Hillhater]

Has anyone found any reasonably priced power, or volt/ amp meters , with logging memory facility , for use on bike , or even on the bench ?.....other than the CA ?