Battery Charging Question (ready made pack vs single batteries)

[WCRR152]

I have started to work on going RC with Piko’s key fob remote style RC kits. The question I am running into is working with batteries up until this point I have stuck with RC car style batteries which are basically shrink wrapped AA, AAA, or C cell batteries that are NiMh. I usually have added a charging socket so I don’t have to disassemble the entire locomotive to charge. But I am now working on some smaller British Gauge 1 tank locomotives (a1x Terrier) and the commercial battery packs are right at the top size I can tuck into the boiler and side tanks. Is there a way to string single batteries together AA or AAA to basically be able to charge them as a pack or would the difference in battery cell potential prevent this?

 

[dunnyrail]

I have started to work on going RC with Piko’s key fob remote style RC kits. The question I am running into is working with batteries up until this point I have stuck with RC car style batteries which are basically shrink wrapped AA, AAA, or C cell batteries that are NiMh. I usually have added a charging socket so I don’t have to disassemble the entire locomotive to charge. But I am now working on some smaller British Gauge 1 tank locomotives (a1x Terrier) and the commercial battery packs are right at the top size I can tuck into the boiler and side tanks. Is there a way to string single batteries together AA or AAA to basically be able to charge them as a pack or would the difference in battery cell potential prevent this?

I have done a Gauge 1 Terrier, Tower Models one. It was a bit of a faff but I managed to squeeze a Battery Pack in to my own specifications supplied by Fosworks. You can but AAA with Tabs to solder but I took the easy way out as it can be a bit of a challenge getting them all connected and heat shrinked up. I also used Fosworks DCC Rx/Tx and a DCC chip. Fitting it all in was a real bit of fun with some adaption and cutting of the original loco. Can post some pictures for you if it is any help.

 

[PhilP]

A commercial pack is made from individual cells, but with a 'flat' positive connection..
These cells are usually tagged with nickel silver strips, welded between them, to create the pack.

You can specify 'boiler packs' where the cells are split into two, which means that they will fit in side tanks.

Another alternative, is to use Lithium batteries.. Each cell gives 3.7V so you need less of them.
A charger specially designed for this type of battery must be used, and it is best to buy packs with protection electronics built in.

PhilP

 

[Rhinochugger]

Yep, if you don't want to go Li-po (and there are pros and cons with that) then consider using smaller NiMh packs wired in series - I've done it in a number of R/C conversions and it's much better than using individual re-chargeable cells

 

[Greg Elmassian]

I'm wanting to understand exactly what you are asking:

1. can you mix a "string" of AA and AAA batteries
2. can you use a "string" of one type of battery
3. can you charge either of the above as a single pack? i.e. a single plus and minus connection to the "string" for charging.

I also make the assumption "string" means single cells in series.

Greg

 

[GAP]

I do not know what dimensions you are dealing with but I have just made a battery pack the fits into the boiler of an LGB 2076 which is not that big, about Stainz size.


I used four 2/3A aircraft receiver batteries they are rated 6V 1500mAHr so I connected two lots in series then paralleled them up to get a 12V 3000mAHr battery.

Turnigy Receiver Pack 2/3A 1500mAh 6.0V NiMH High Power Series

Turnigy Receiver Pack 2/3A 1500mAh 6.0V NiMH High Power Series

hobbyking.com

 

[GAP]

I'm wanting to understand exactly what you are asking:

1. can you mix a "string" of AA and AAA batteries
2. can you use a "string" of one type of battery
3. can you charge either of the above as a single pack? i.e. a single plus and minus connection to the "string" for charging.

I also make the assumption "string" means single cells in series.

Greg

I think he means connecting them in series

 

[Greg Elmassian]

Yep, just making sure of the terms before I suggest anything... your examples of series/parallel will be the next question in case he adds that complication.

Greg

 

[Rhinochugger]

Yep, just making sure of the terms before I suggest anything... your examples of series/parallel will be the next question in case he adds that complication.

Greg

Yeah, and a sensible check on the AA / AAA front - I hadn't thought to question that

 

[Greg Elmassian]

Maybe I am somewhat overboard (ok quit laughing!) in my questions , but it's hard sometimes to really understand what is exactly being asked.

Not everyone uses the same terminology.

Greg

 

[WCRR152]

Greg, Yes, more or less trying to make a series connection of AAA cells to make a battery “pack” that was split into 2 physical locations that could be charged together but as GAP pointed out it might be better just to buy two small battery packs off the shelf and then wire them in series to get the desired voltage. (Somewhere in the 6-8 volt range). I have added pictures of the engine. It is 3D printed.

 

[WCRR152]

I do not know what dimensions you are dealing with but I have just made a battery pack the fits into the boiler of an LGB 2076 which is not that big, about Stainz size.

Did some measuring looks like one of those 6 volt batteries will fit nicely in the smoke box, so I am going to go ahead and try to source one of those. Thanks for the advice.

 

[GAP]

Did some measuring looks like one of those 6 volt batteries will fit nicely in the smoke box, so I am going to go ahead and try to source one of those. Thanks for the advice.

Have a scan through this to see if anything fits the bill for what you are looking for.

NiMH

View our selection of durable and high-performance NiMH battery packs for maximum fun. Enjoy the best prices with quick international shipping.

hobbyking.com

 

[dunnyrail]

I do not know what dimensions you are dealing with but I have just made a battery pack the fits into the boiler of an LGB 2076 which is not that big, about Stainz size.

View attachment 284819
I used four 2/3A aircraft receiver batteries they are rated 6V 1500mAHr so I connected two lots in series then paralleled them up to get a 12V 3000mAHr battery.

View attachment 284818

Turnigy Receiver Pack 2/3A 1500mAh 6.0V NiMH High Power Series

Turnigy Receiver Pack 2/3A 1500mAh 6.0V NiMH High Power Series

hobbyking.com

Have made up some of my own battery packs but those look good for a couple of projects on the go so have ordered some. But oh my what a faff getting an order in with Hobby King, must be one of the most user antagonistic ordering sites on the Webb.

 

[GAP]

Have made up some of my own battery packs but those look good for a couple of projects on the go so have ordered some. But oh my what a faff getting an order in with Hobby King, must be one of the most user antagonistic ordering sites on the Webb.

Don't know what happens on you side of the planet, I use the Australian warehouse and just created an account with then using my email and using a password I have bought from the global one as well.
Click on the item, add to cart, then go to checkout.
Navigating around is a bit cumbersome but considering the amount of stock they carry that could be an explanation.

 

[dunnyrail]

Don't know what happens on you side of the planet, I use the Australian warehouse and just created an account with then using my email and using a password I have bought from the global one as well.
Click on the item, add to cart, then go to checkout.
Navigating around is a bit cumbersome but considering the amount of stock they carry that could be an explanation.

Most of my issues were about password as I had an account that I had oreviously ised and was going round and round in circles then my address had not been remembered and finally the items that I had ordered some time back and received were still in my cart! Also a pain that they are shipping from differing Countries, this order was reduced when I realised that 4 of the items I wanted (not the batteries) would be shipped from Japan. Not doing that sort of thing now for 4 quids worth of connectors that I can source in UK.

 

[PhilP]

You could have just picked up the phone to Roger at Strikalite?

They have many 'odd' sizes of NiMH cells, and would make to your specification..

PhilP

 

[Rhinochugger]

You could have just picked up the phone to Roger at Strikalite?

They have many 'odd' sizes of NiMH cells, and would make to your specification..

PhilP

Yep, Jon could have, but our enquirer WCRR152, despite flying the Union Jack, is in Kentucky

 

[dunnyrail]

You could have just picked up the phone to Roger at Strikalite?

They have many 'odd' sizes of NiMH cells, and would make to your specification..

PhilP

Think the problem is I do not know all the odd sizes of NiMh other than AA,AAA and sub C. so these packs x Hobby King looked to be worth a punt at the price.

 

[Rhinochugger]

Think the problem is I do not know all the odd sizes of NiMh other than AA,AAA and sub C. so these packs x Hobby King looked to be worth a punt at the price.

That's why it's worth talking to Roger - tell him the space available and he'll make something to fit