Keeping track of battery charging

[gregh]

I now have about 25 vehicles fitted with batteries, so I thought some of you might be interested in how I keep them charged.

As you can see in the pic, I made up a blank excel spreadsheet listing all my batteries across the page and a `calendar` down the page. I add the coloured lines as I charge each battery.  I use blue color when they are charged using my two, Turnigy  automatic chargers, and red for my home made trickle chargers. ( I don`t really know why I differentiate. )


This way I can ensure all NiMH batteries are topped up every month or so, and track if any are getting so bad that they self discharge completely in a month.  And I can check how long the charge lasts on the LiPos.

If you can read it you`ll see that I killed the LiPo in loco #2 in february and had to replace it, and I`ve had 3 different locos flat when I tried to use them, so they will be monitored closely. I replaced the NiMh in the CPH last week.

In addition to the batteries in locos, I have six  2.4 GHz transmitters with rechargeable NiMH - these are always on a trickle charger of my own design, whenever I`m in the train room.
My next projest is a trickle charger for the eight,  9V batteries I have for carriage and station lighting.

 

[ge_rik]

Useful idea Greg. I'm getting to the stage where I'm needing something like this - though my fleet is nowhere near as great as yours. I have noticed though how quickly the NiMH powered locos self-discharge. How important is it to keep these topped up? The Li-ion batteries seem to hold their charge indefinitely.

Rik

 

[spoz]

Now, that's a good idea. I don't have anywhere near that many locos, but I also don't have a clue when I last charged them other than the feeling that either "it was recently" or "it was some time ago". It could obviously also be adapted to track replacement of the throw away 1/2 size AAs I use in the garage door openers which are my controllers; not knowing that their batteries were due for replacement has embarrassed me on more than one occasion. Thanks Greg!

 

[Tony Walsham]

Good idea Greg.
What it does show clearly is that NiMh batteries self discharge, rapidly at times.
Every time they do that it reduces the recharge life of the battery by one even if you have never used it for powering a loco.
NiMh start with only 50% of the recharge capability of NiCd and then lose even more by self discharging.
IMHO that built in planned obsolescence of NiMh has been the great con job of the battery industry.
So bad has it been that LSD hybrid NiMh / Alkaline batteries had to be introduced for the digital camera market.

 

[gregh]

I would just caution everyone against using the 3 months of CHARGING data in my example, to make any decisions on the relative merits of battery types.
All that my data shows is when I charged a battery, not how much charge it needed and nothing about how I had used (discharged) the battery. Had it sat there for month or had I used it a lot?

I welcome suggestions on how I could incorporate the 'usage' or discharge data onto the spreadsheet.
If I use my Turnigy chargers, I can record how many mAh I put in at each charge. But I can't measure how much I've used after any run of the loco, unless I charge it.
Maybe I can just guestimate that I used 1/4 or 1/2 of the battery capacity and note that on the sheet.

At least with LiPos I can measue the voltage and get a very accurate estimate of the charge remaining.

 

[dunnyrail]

Gregh,
Perhaps you could insert another Column to represent week 1 - 4 of each month. Then when you run each loco another Dot to show it was run. This may only represent a small indication but would be perhaps better than nothing. If you run more often than once a Week, the more Columns.
JonD

 

[tramcar trev]

I only have one battery tram so far and my charging technique was totally ad hoc i.e. when ever I thought to do it. But what I did was create repeat entries on my phone "Calendar" that reminds me to charge the batteries every 21 days. Of course the batteries are charged after use as well....
Not going to work with more than a couple of batteries though unless you have a very smart phone or a dedicated App...

 

[KandNWLR]

Good idea for those of us who (still) use batteries for R/C - and haven´t gone totally manual yet.

 

[gregh]

Gregh,
Perhaps you could insert another Column to represent week 1 - 4 of each month. Then when you run each loco another Dot to show it was run. This may only represent a small indication but would be perhaps better than nothing. If you run more often than once a Week, the more Columns.
JonD

I like that idea. I think I'll divide each loco's column into 3, then put a dot in each time I 'think' I've run for about 1/4 hr. After 3 dots I'll recharge.