Large Scale Central

Question on using multiple Li-Ion packs in a loco

Electronics Power and Sound
#1

Try as I might, I just cant fit the 3-cell Lion pack I purchased along with the RailBoss, and a Phoenix P5 & speaker inside the boiler/tanks of my Side-Tank Porter.

One solution is to change to two 7.4V two cell packs, putting one in each tank. This leaves the boiler shell free for the electronics.

Here is the question - These packs come with a PCB to limit charge and discharge. I know from reading the All-Battery website that two packs can be wired in parallel to double the current and charged as one unit.

Can two packs with PCB be wired in series to double the voltage and still be charged as one pack?

#2

Jon,
The Regal says All Battery sells a harness to do just what you want.
Ralph
http://www.largescalecentral.com/LSCForums/viewtopic.php?id=13859

#3
Jon Radder said:
Here is the question - These packs come with a PCB to limit charge and discharge. I know from reading the All-Battery website that two packs can be wired in parallel to double the current and charged as one unit.

Can two packs with PCB be wired in series to double the voltage and still be charged as one pack?


Give it a shot…if I don’t see a mushroom cloud appear in the northeast sky, I’ll know you got it right…:wink:

#4

BOOM

#5

Ralph - That Y Adapter is for NiCad - NOT Li-Ion! !! From what I am able to find you SHOULD NOT charge battery packs wired in series. Up to two packs can be charged in Parallel. So I thought about it a bunch and came up with this circuit to switch the packs from Series wiring for RUN to Parallel wiring for charge…

(http://lsc.cvsry.com/RailBossChargeCircuit.jpg)

Still waiting on official word from All Battery’s tech support. I do not want any mushroom clouds, thank you very much :slight_smile:

#6

Very good Jon. Nice to see you engineered a way around the problem.
I guess I didn’t read the Regal’s post very thoroughly :open_mouth:
Ralph

#7

In theory Ralph. Now the challenge is to find a 3PDT switch that will fit where I wanted to put it.

#8

OK. Just got an email from All-Battery tech support.

I posed the question as.

[i]I have an application for Li-Ion batteries where space is limited. I need 14.8V @ 2200 mAh but must split the batteries into groups of two cells each.

Could I use two 7.4 packs (item 31003) wired in series ? If so, could they be charged as one 4 cell pack using the Tenergy TLP-2000 Charger ? [/i]

And got this response…

All Battery said:
Yes, It can work. Thanks, Customer Service Stephanie
No mention of mushroom clouds, etc. nor confirmation of how I set my charger. I'm guessing set it at 4 cells and take cover.
#9

Jon??? did their email come with a disclaimer??? or a self destruct notice??? something to the effect: ““If your batteries blow up, this email will self-destruct, and we will avow any knowldge of any such transmission””

:slight_smile: hehehe

#10
Andy Clarke said:
Jon??? did their email come with a disclaimer???? or a self destruct notice??? something to the effect: ""If your batteries blow up, this email will self-destruct, and we will avow any knowldge of any such transmission""

:slight_smile: hehehe


Surprisingly not. The quote above was the entire email.

The first charge will be done according to the safety instructions included with the batteries… Outdoors in a fireproof container at least 50 feet from any flammable items :slight_smile:

EDIT to correct distance typo. 590 feet was a lot more interesting, but overstated :slight_smile:

#11

Boom

#12

How about KA BOOM!!! :wink:

#13

noticed a very bright lite up there in the northeast…Jon musta charged his batteries…:wink:

#14

I don’t see any problem with what you are doing. You simply need to set the voltage setting for 14.8V if you have the two 7.4V packs in series. The charger is set for a constant charge current, so nothing to worry about there. If the charger doesn’t detect end of charge, the on-board PCB safety boards will cut out. One would quit before the other. So worst case, you may not get 100% charge on one pack. Really no different than the fact the individual cells don’t all receive 100% charge without cell balancing connections.

#15

Thanks Del. I really didn’t want to add the complication of the 3PDT switch since I already have a charge/run switch wired. Need to mock-up the two 7.4’s and do a good test fit. If all goes well with that I’ll order them as an Xmas gist to myself :slight_smile:

#16
Ken Brunt said:
noticed a very bright lite up there in the northeast.................Jon musta charged his batteries.......;)
Nope ....that was the sun reflecting off my Amtrash stuff! ;)
#17

Wrong direction…:wink:

#18

Jon,
I have a few dual battery applications in my trains.
I simply made a harness with diodes. I just unplug the harness and charge the Li-ions separately.
Course, It is a different application than yours.
I just lift the coal load to access the batts.
Long ago, I stripped all of my battery cars and locos of all the unnecessary crap such as charging jacks and switches.
Coal loads and oil bunkers lift off. Battery cars are gons with loads, tanks, etc.

#19

Thanks John. Interesting idea. Unfortunately in this loco everything must be buried in the boiler and tank shells. No bunkers / tender to make life easy.

I heard Santa Claus might be bringing the new battery set. Look for a mushroom cloud north of NYC on Christmas Day :slight_smile:

#20

(http://smileys.smileycentral.com/cat/28/28_1_19.gif)