18-cell charger?

[Juggernaut]

Ok I'm looking for a 18-cell charger, my current charger can't handle that many cells and taking apart a 18 cell battery pack every time I need to charge it really sucks, so what would be the cheapest solution to this problem?

I found this http://www.batteryjunction.com/uspc804.html which I think would work because 18 cells = 20 volts, but it does say 20-cell charger in the description so Im not sure if it will work, or do I buy this: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=7386, this says it will do 18 cells, but I dont want to spend $50 on a hobby charger that does everything the one I own does with the exception of charging 4 more cells at once:ohgeez:.



Thanks for helping:thumbsup:!

 

[HarryN]

Hi, I use one of these Triton II chargers.

http://www.electrifly.com/chargers/gpmm3153.html

It is a hobby charger, so it is designed to be fed 12 VDC and charge up r/c cars, etc.

There are other firms that make these types of things as well, but it is sort of my go-to charger for most stuff around the house.

To feed the power from an a/c source, you will also need an AC - DC adapter, a healthy one. I have about $ 170 in my combo, but that was several years ago, so it might be cheaper now.

Just in general, regardless of brand, if you are charging up an expensive pack like that, a decent hobby charger will give you much improve pack life over the low priced ones.

Good luck

Harry

 

[VidPro]

agree , when you got that many cells, a cheap hobby charger might not handle it as well as the tritons.

all the cells are in series right? no series parellel going on at all?
and the cells are nickle based not li-ion?

there is the Slow charge method. old school, where you charge at a way slower rate, like 1/10C and charge for 12-14 hours, depending on how far it is discharged. Then you prefer to not leave it charging, when it is mostly done. Problem with this is, it is more preferable to have a faster charge, because it knocks stuff back into place better, and can form it up for a faster discharge. but it is cheap, was done for ages, is still done with various series packs sold to consumers.

then there is a modified voltage maximum charging method, which takes much tuning, and watching, and requires feeling out the correct voltages, and setting the right currents. it is similar to the above slow charge, except the voltage of the charge is set so it charges faster when the battery is low, and slower when the battery is high. You just get any ol adjustable voltage power source, with a current limit, or current maximum, and tune the voltage for your whole pack. this method offers the advantages of a CV type of charging, can balance out the cells, can form relatvie to the uncharged chemicals, and can slow down further even then the 1/10th charge. Set the wrong voltage, and it all goes to heck.

25volt transformer, fat bridge rectifyer, big 35volt capacitors, linear adjustable voltage regulator, volt and amp meter. about $50 :-) exactally what you did not want to spend.

that charger that you listed, says 1 amp and 1.5, and V-drop termination, which just leaves topping to balance , will it do that too?? for $24 :-)

 

[fivemega]

Ok I'm looking for a 18-cell charger, my current charger can't handle that many cells and taking apart a 18 cell battery pack every time I need to charge it really sucks, so what would be the cheapest solution to this problem?

This may work for you but if you can spend more for hobby charger, it will do much better and charge different chemistry cells when needed.

 

[VegasF6]

The cheapest solution is to just keep taking it apart :)
Seriously though, is it possible with your battery pack to charge them 9 at a time without dis-assembly? Can you get to the contacts I mean? It wouldn't be fun to charge it in 2 halves so to speak, but it should be safe enough, and meets the criteria of cheap.

 

[KiwiMark]

For a good price this:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7523
can charge up to 27 cells in series with the charge rate not exceeding 150W or 7A, you would need to utilise an old PC power supply or other suitable 12V source to power it though.