Lithium-ion batteries - some hands-on experience

[MRail]

Re: Lithium-ion batteries - some hands-on experience

Thank you sir, looking on eBay, I was wondering about the flying leads.

Any thought on the feasibility of using two batteries in series?
Of course it would be mandatory to re-charge separately.

(Header edited by Mod to get correct thread title back!)

 

[MRail]

Thanks, Ross.
It's mainly a theoretical question, since 22.2V packs are available.
Packs appear to be made up of individual cells in series, so I'm guessing two 12V packs in series is much the same.
The packs Whatlep is using come with a charger - seems a better deal to buy two packs with chargers than one without.

 

[whatlep]

A quick update on this topic, especially the newer, blue battery.

In an idle moment this week I decided to measure the voltage of the blue battery. To do so I used the socket lead which is designed to be attached to the charger. All fine on the voltage, but afterwards I realised that I had obtained a voltage reading while the battery's switch was set to "off". A bit of testing confirmed that the switch only interrupts supply to the "male" lead. The "female" lead is permanently "live"!

Now this isn't a colossal problem, but it may be wise to be aware of it, just in case. It would be a shame to short out the battery accidentally. The original black battery only has one combined input/output socket which is switched by the battery switch, so the problem does not arise.

Both batteries continue to perform impeccably with sterling performance no matter how much I demand from them.

 

[Madman]

Thank you for posting your findings on the batteries from China. I just purchased two of them, and was curious as to anyone elses experience with them.

 

[Madman]

A quick update on this topic, especially the newer, blue battery.

In an idle moment this week I decided to measure the voltage of the blue battery. To do so I used the socket lead which is designed to be attached to the charger. All fine on the voltage, but afterwards I realised that I had obtained a voltage reading while the battery's switch was set to "off". A bit of testing confirmed that the switch only interrupts supply to the "male" lead. The "female" lead is permanently "live"!

Now this isn't a colossal problem, but it may be wise to be aware of it, just in case. It would be a shame to short out the battery accidentally. The original black battery only has one combined input/output socket which is switched by the battery switch, so the problem does not arise.

Both batteries continue to perform impeccably with sterling performance no matter how much I demand from them.

Did I read, somewhere in this thread, that when you charge one of these batteries, the switch, on the battery, should be set to "ON"?

 

[MRail]

Quote: Did I read, somewhere in this thread, that when you charge one of these batteries, the switch, on the battery, should be set to "ON"?

The original black battery only has one combined input/output socket which is switched by the battery switch,

Dan,
That would appear to be true for the battery with only one combined I/O socket.
The one with separate socket/leads would presumably not.

 

[whatlep]

Quote: Did I read, somewhere in this thread, that when you charge one of these batteries, the switch, on the battery, should be set to "ON"?

The original black battery only has one combined input/output socket which is switched by the battery switch,

Dan,
That would appear to be true for the battery with only one combined I/O socket.
The one with separate socket/leads would presumably not.

The answer to the original question is "yes" for the black battery. Its design assumes it's impossible to have both a charging supply and a load being drawn off the battery at the same time. That's true if you only use the supplied leads.

For the blue battery, when charging you need to either disconnect the output (switched) lead from whatever it supplies, or turn the switch to off. Otherwise you are trying to draw power at the same time as charging the battery.

In our hobby, it seems prudent to take two wires from the battery to a "changeover" switch which ensures that the battery can only ever be set to charge or supply current to the attached circuits. For the black battery, that means carefully cutting into the supplied lead while not attached to the battery. For the blue battery, cut into the switched lead and tape over the charging lead with insulating tape. Cutting into the charging lead on the blue battery risk shorting out the battery, since it is permanently connected to the battery and "live" at all times.

 

[MRail]

Thank you,
That all makes sound sense.
I've been pondering about going down this route, and that's exactly what I need to know.

 

[nicebutdim]

You can get switched charging jack sockets. These cut the load supply automatically when the charging plug is pushed in.
I think this is the type http://www.maplin.co.uk/Module?ModuleNo=1407&C=Froogle&U=1407&T=Module < Link To http://www.maplin.co.uk/M...mp;U=1407&T=Module

 

[Madman]

Thanks.
And I should have asked this question at the same time, I was also wondering about the charger. Apparently, it cuts off on it's own, when charging is complete, Yes? No?

 

[whatlep]

Thanks.
And I should have asked this question at the same time, I was also wondering about the charger. Apparently, it cuts off on it's own, when charging is complete, Yes? No?

Yes! All the batteries on eBay I've seen seem to come with the same charger which is able to use any international input voltage, outputs 350mAmp trickle charge and auto-detects when the battery is fully charged. Very impressive for the money. The Chinese suppliers I've dealt with also provide an appropriate mains plug on the charger for your local electrical socket.

 

[CoggesRailway]

An interesting read..... I am venturing, with Whatleps help, into this territory too.

Interestingly as I am working at home I set off my new little bashed 0-4-0 with a LGB gondala filled with gravel (heavy) behind it at 9.00. As I type (12.20) it is merrily going round the garden at the same speed. This was not Li but the cheapest battery for an rc car. I am still really impressed, much longer than needed - battery technology seems to have improved alot even with low end stuff.

 

[tramcar trev]

I had experiences with Lithium batteries I'd not want anyone to have. These were double "D" size with a liquid electrolyte that could be heard when you shook the battery.
They were prone to spontaneaous combustion and had a very nasty habit of simply self igniting....
I don't think they are available anymore. Yuasa was the brand....

 

[CoggesRailway]

reference my earlier post, it's still not slowed after 7 hours with a heavy train!!!!

 

[yb281]

reference my earlier post, it's still not slowed after 7 hours with a heavy train!!!!

Careful you don't wear your track out mate.

 

[whatlep]

reference my earlier post, it's still not slowed after 7 hours with a heavy train!!!!

On your relatively level track you should easily beat my current 8.5 hour "best time". Good stuff Li-ion, isn't it?

 

[Madman]

I applaud my decision to convert to battery power I don't know what took me so long.

 

[MRail]

Good stuff Li-ion, isn't it?

Whatlep,
Just wondering if you're in a postion yet to comment on how well the batteries holds charge when not in use?
I guess you probably haven't left them idle for long.

 

[whatlep]

Good stuff Li-ion, isn't it?

Whatlep,
Just wondering if you're in a postion yet to comment on how well the batteries holds charge when not in use?
I guess you probably haven't left them idle for long.

Good question. Since I created my "lunch box" pack, my original black battery hasn't been charged for over one month and has had very limited use during that time (probably under 15 minutes). Measuring it a few minutes ago, the voltage output has dropped from 12.63 to 12.38: exactly 0.25 volts. The manufacturer does warn that the batteries need using (discharge/ charge) at least once per year! I've now set that battery aside with a reminder on it to measure the output periodically, so watch this space.

 

[MRail]

Thanks for the info.

Thought of another question...
I would fit the battery into a loco, rather than a trail car, what's the feeling about charging in situ?
If it has to be removed, because of heat or other risk, then it's another ball game.
Of course it the charge lasts several months, then it may be viable.