New Battery...again

[MetroMan]

Kevin,

I can try to explain further.

[h20resq420]

Hey Kevin,

That's not exactly what I'm saying. Let me explain further as best I can.

The Lithium batteries use a PCB/PCM (Protection Circuit Board/Protection Circuit Module) to protect the battery from over charging and over-discharging. Either extreme can ruin one (or more) of the cells within the battery pack. There are many different PCMs, having different maximum discharge rates. Our Torques draw up to 29A at full throttle from a stand still. Quite a few of their batteries contain PCMs that limit the discharge (Amp draw) to numbers below 30. These batteries won't work, as they shut off when that threshold is reached. Mine has a limit of 60A. My yellow battery has a 40A limit.

Based on when I first got the torque, this new 40aH battery lasts about the same as my old 50lb AGM battery. This was my first and only time out with this new battery, so that's a rough estimate. This last trip had quite a good mix of full & partial throttle operation. From past experience, full throttle is never worth using for any prolonged period of time. The amp draw increases substantially between half throttle and full throttle, yet the speed gains are minimal. I spent a bit of time at full throttle, which naturally ran the battery down faster than a normal fishing trip would. Next time out, I plan ot have my "meter" hooked up to get some more accurate numbers.

Ok...Understood. I going to PM you a message.

[On the fly]

Thanks. I plan to use velcro to keep it in place in the hull. I THINK thats what I want to do...

The only problem I found was the Velcro adhesive does not adhere for long to the kayak hull.

[MetroMan]

Ugh. I was afraid of the moisture causing the adhesive to loosen. I'll figure something out...


Sent from my iPhone using Tapatalk

[john from md]

Velcro works when you glue it on with GOOP. Trust me, my OC has been turtled with the mod pod open and the velcro is still there.

MM Are you using a Watt's up meter? If so, can you tell me what readings it gives you and what the wiring sequence is?

Thanks,

John

[MetroMan]

Ok, I will try the velcro with goop for the adhesive.

For the meter, I have used this (which is basically the same exact thing)



It tells a bunch of different measurements, but the ones that are important are: Voltage; Amperage (shows the real time current being drawn), and the AmpHour reading, which shows the actual number of aH consumed since start up.

It works great, and is easily installed/removed in-line since I already use power pole connectors.

I wire it just like this:
Capture.JPG

It rests in my hatch, easy for my to monitor from my seat without moving.

The only problem is that they are not durable, and not designed to withstand marine use. I have gone through three of these... I am looking for cheaper, more durable solutions.

Here is the same thing...different brand, lower price
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

[archeryrob]

Excellent work on the battery as always, but am I reading this right? $560 for 2 batteries in series to be 40ah?

[MetroMan]

Yeah Rob. It is not easy on the wallet...Dont tell my wife

[buzz]

Yeah Rob. It is not easy on the wallet...Dont tell my wife

LOL
Your secret is safe here.

All this stuff is way over my budget yet I find the information quite interesting. You've put in a lot of research and bench time to figure all this stuff out. I was wondering what you thought of a turn-key solution like this one.

Smart Battery 12v 40Ah Lithium Battery

[MetroMan]

It looks fine, and should work just fine. I'd prefer to have the ability to easily disassemble the battery. Should the battery pack die, if you can readily take it apart, you can isolate the bad cell and replace it (which is cheaper than replacing an entire battery). A pro to that battery is that is is fully encased, requiring no battery box construction..."turn key".

[john from md]

MM, how about if you encapsulate the unit in a clear polymer of some type. Do you think that would make it last longer?

Regards,

John

[MetroMan]

It has vents on the back, so I can't impede the air circulation, or else it will overheat. I might try to apply a "conformal coating", which is designed to provide protection to printed circuit boards, while still allowing them to remain cool.

I just ordered two meters on eBay, $17.99 ea. Same item, just different brand name from China.

[john from md]

I have read several posts where the posters say that the China version is giving them the same quality as the more expensive Waat's Up model. One guy has encapsulated a unit but he never replied as to whether it worked or not.

I wasn't thinking too much about amperage draw until I saw your schematic. Pulling 40 amps without a big heat sink can definitely be an issue. Without enough cooling, the unit literally would be toast.

John

[buzz]

MetroMan.... have you looked into supercapacitors?

The other day while browsing YouTube, I came across a video of a guy starting his car engine with a 6-pack of "D" size supercapacitors.

I know supercapacitors have the ability to discharge gradually. But can they be used to run a trolling motor?

[MetroMan]

LOL @ the chickens. I have never looked into super capacitors.