Chargers = low voltage

I seem to have run into a few problems with my chargers and power supplies.

When the chargers are in stand by everything works fine, and when I charge the batteries at less than 1 amp, everything works fine. The chargers read 12 volts from the power supplies and the 15 amp fuse hasn't blown. But I am supposed to charges the Li-ion batteries (a123) at 5 amps and when I bring it above 2, I get a "low voltage error" from my chargers.

I was wondering if anyone had any experience in this field and might be able to tell me what I am doing wrong. Thanks.

SenaiERI

P.S. Man I suck at electrical work. This is like my 3rd electricity post.
Hopefully I don't electrocute myself before the competition.

how big is your power supply? If it's too small, it won't be able to output enough to run your two chargers at enough amps to charge your batteries. Power (P) = Current (I) x Voltage (V) so if you've got a 120 W power supply, and it puts out 12V, that's 10A to split between your chargers, but they draw power too, it's probably small, but it's there, so it's really less than 10A for charging, which won't let you charge at 5A. Instead, your power supply will supply the adequate amount of current, but drop the voltage.

I know that if you use THIS charger, the Thunder Power THP610C, for your A123's, it has a setting that lets you change the minimum cutoff voltage to power the chargers. If that's set at 11.5 or something like that, and your power supply dips below that, it will tell you that it's got low voltage. But they can run as low as 10V!

If you can tell me what power supply and chargers you're using, it would be helpful. :]

Yeah charger info might be helpful.

I am using the 123 li-ion astro flight chargers and I'm actually giving each charger its own power supply. I have one PC power supply which can handle 13 amps and outputs 11.6 volts and another power supply that can handle up to 24 volts but I'm not sure of the amperage. The EE department that I got it from said it could easily handle 15 amps and is similar to this: http://www.robotmarketplace.com/products/0-ACDC100W.html

Now I can't even go above .5 amps without and error.

SenaiERI

The EE department lied. All pc power supply manufacturers lie about the amperage there products can output. For the A123 chargers you need 12 volts at at least 10 amps. not 24 volts.

I bought 10 MeanWell power supplies earlier this year that work perfectly. You can find them on mouser.com if you search for part #709-S150-12.

If you want to come grab one or two, I'll let you borrow them for the competition.

MattTavares wrote:

The EE department lied. All pc power supply manufacturers lie about the amperage there products can output. For the A123 chargers you need 12 volts at at least 10 amps. not 24 volts.

I bought 10 MeanWell power supplies earlier this year that work perfectly. You can find them on mouser.com if you search for part #709-S150-12.

If you want to come grab one or two, I'll let you borrow them for the competition.

Ah thanks Matt. That's sweet of you. But you already sent your non-essntial stuff already right? I want to get these packs cycled and peaked once more before I ship em.

My batteries haven't actually peaked due to obvious reasons but my ps's should be able to do what I need right? They can go up to 24 volts but it's variable and I currently have it set to 12.5 volts. I'm sure they can handle the amps, but I probably just screwed something up.

BTW, I'm not buying anything else. The bank account is already drained and they probably can't ship it to me by Monday anyway.

Any suggestions on getting my current config working?

SenaiERI

SenaiERI wrote:

MattTavares wrote:

The EE department lied. All pc power supply manufacturers lie about the amperage there products can output. For the A123 chargers you need 12 volts at at least 10 amps. not 24 volts.

I bought 10 MeanWell power supplies earlier this year that work perfectly. You can find them on mouser.com if you search for part #709-S150-12.

If you want to come grab one or two, I'll let you borrow them for the competition.

Ah thanks Matt. That's sweet of you. But you already sent your non-essntial stuff already right? I want to get these packs cycled and peaked once more before I ship em.

My batteries haven't actually peaked due to obvious reasons but my ps's should be able to do what I need right? They can go up to 24 volts but it's variable and I currently have it set to 12.5 volts. I'm sure they can handle the amps, but I probably just screwed something up.

BTW, I'm not buying anything else. The bank account is already drained and they probably can't ship it to me by Monday anyway.

Any suggestions on getting my current config working?

SenaiERI

I didn't ship ALL my power supplies. just 6 of them. I am using two int the lab still but that leaves two that you can borrow.

Well thank you very much mr. tavares. You've been a big help to your opponent. Can I pick them up tonight?

Let's try and keep everything in this tread before other people reading this get confused.

I have 2 chargers and 2 power supplies. 1 pc power supply that gives 11.6 volts and 1 power supply similar to the one you have. It can run at 24 volts but I have it running at 12.5.

I'm not afraid the packs won't peak I'm saying that it's taking them for ever to peak because the charges won't go over 1 amp without the low voltage error, so wanting them to charge in an hour isn't gong to happen.

SenaiERI

Bring all the battery's and chargers that you have and we can work it out. ill be heading up to UTD here is about an hour or two. any time tonight after that works for me.

I'd like to finish up here around 5 or so. How late will you be at utd?

SenaiERI

Oh damn. I was planning on leaving at 4:59...

Actually I will probably be leaving around 9:00 - 10:00 tonight.

SWEEEEEEEET!!!!!!!!!!!!!!!!!!!!!

I wanna see Blender mini spin up too.

SenaiERI

you should take your bot to so they can play together

Thats what I keep telling him but he doesn't want me to see his robot before the competition even though he has seen mine about 100 times

thats not fairrrrr!!!

WOW WOW WOW HOLD ON NOW!

1) I didn't ask to see blender mini. I go to the high school, it's sitting on the table. I visit him at UTD and it's sittin there again. If he came up to UTA once in a while I'd have no problem showing him Tornado Mini.

2) There really isn't that much to show. It's Thunderstruck un-upsidedown and hopefully without the crappy driving.

It's not a big secret, but it's nothing special either.

Matt, if you're that curious and want to see that bad. I will bring it to utd...as long as you have a printer or monitor for me to smash. You don't know how unbearable it is to be sitting next to a pile of old computer junk just begging to be destroyed and you can't touch any of it.

SenaiERI

P.S. Oh and Cody, you're not the only other kid NOT from Florida. DALLAS TEXAS KICKS ASS!

hahaha sorry senai i fixed if for you, although i wish i lived in texas!

Im not sure what you mean by thunderstrike un-upsidedow lol

Im sure you could find something to beat up, your just not trying hard enough
You could always take a turn on matts garbage can too!

lol, Bring it. I have plenty of stuff to blow up.

oh yeah, I forgot about that trash can.....ummmmmm.
I have a broken rapid prototype machine sitting next to me. It'd be a nice appetizer for Tornado mini's main course, Blender mini.

The "un-upsidedown" reference meant that Thunderstuck was designed to be flipped over an taken apart from the underside. Everything was mounted on the top plate for easy access, but there were some bugs we didn't get worked out. It was a good idea just with some minor flaws.

Tornado mini is like Thunderstuck in its secret weapon that Matt already knows BECAUSE HE SAW IT and I don't want my other opponents to know.
I've probably said too much as it is, but there you go Eddie and Interstellar Drive. Now you know.

Texas is awesome, but you didn't have to change anything.
I say we spread battlebots all over america. Matt and I have the south covered. The florida people have the south east. If you started a club where ever you go to college, we could spread the addiction of battlebot to everyone.

SenaiERI

I got a printer that needs to be blown up as well

I think PA has BotsIQ down atleast in high schools haha

I go to Penn State, and im just not sure if i have the resources to do it as id probably end up doing by myself too and im not sure about funding either.

How did you guys get your "clubs" together and do you have any tips?!

Cody Harris wrote:

I think PA has BotsIQ down atleast in high schools haha

I go to Penn State, and im just not sure if i have the resources to do it as id probably end up doing by myself too and im not sure about funding either.

How did you guys get your "clubs" together and do you have any tips?!

Schools have butt loads of money. They just don't tell you.

Yeah people are dumb. Last year matt ended up doing everything on his own, and now he has a club of people that help him. But this is my first year and I am doing everything on my own. I'm lucky I got in good with the machine shop and they let me do what ever I want, but the first year is always the hardest.

I think the easiest way to get funding is to first show them that you know what you're doing. This was harder for me cause i don't know jack, but one I started to put this thing together, a lot of people started getting interested, students and professors.

I hope I don't sound like a know-it-all. I really don't know anything but that's been my experience so far.

Well im at a branch of Penn State, but my branch is really big with the local BotsIQ, while i am to since i do anything they ask of me haha
I need to figure out who in my school actually deals with BotsIQ.
I know our school has bot loads of money, but they dont like giving it to us at all lol
O well we'll see what happens....

Good luck.

Hopefully there are some really good matches in san fran that inspire innovation. I know my think tank is running low.

Well if I'm going to fight a trash can later, I guess I should put back together Tornado Mini.

See you in frisco.

SenaiERI