batteries and chargers
 

hey everyone,

Build season is coming up soon and my team is pretty psyched.

There is one problem we are having though.

We are trying to find a way to charge 3 or 4 batteries at the same time. Is there a heavy duty battery charger out there we can use? Our battery charging system is insufficient for our needs, so we are looking for a new method.

If anyone has any information on things such as chargers, charging methods, wire maps, or anything of the sort, it would be greatly appreciated.

Thanks again

-Shahrukh

Re: batteries and chargers
 

I would suggest you read the following threads from here, here's a link to them

http://www.chiefdelphi.com/forums/sh...ad.php?t=49603

http://www.chiefdelphi.com/forums/sh...attery+charger

This is a fleet charger that was discussed in those threads.
http://www.interacter.com/X5_page.htm
http://www.batteryweb.com/interacter.cfm

I hope this helps. We would have loved to have something like this ourselves, but it's out of our budget.

Re: batteries and chargers
 

Re: batteries and chargers
 

I would like to strongly discourage the practice of hooking up
multiple batteries in parallel to charge them. Although the
bucket of water analogy has some degree of validity for healthy
batteries, hooking batteries in parallel can have dangerous
consequences in the presense of a battery with a shorted cell,
or should the batteries be hooked up with the wrong polarity.
The safest path is to use an automatic charger, with a current
limit of 6 amps, individually for each battery to be charged.

Knowing that in spite of my reccommendation some teams
will wire batteries in parallel to charge them (I see this in the
pits every year), please make a custom wiring board with fused
anderson connectors that limit the current to each battery to
6 amps if you plan to do this. This will not cost much
money and will prevent hooking up batteries with the polarity
reversed. It will also provide protection in the event that a cell
shorts in one of the batteries.

Please note: I am not suggestin that you exceed the 6 amp
current limit on the charger, replacing this limt with fuses,
as this would be against the rules...


Eugene

Re: batteries and chargers
 

Hooking batteries in parallel to charge them is a fruitless way to go. There is only one right way to charge multiple batteries and that is with a multi charger designed for multiple batteries. Although lead acid batteries do not require sophisticated chargers, the charger provided in the kit and several available in retail or online are "smart" chargers. These "smart" chargers alternately supply charge current and monitor or even slightly discharge the battery to determine charge state. A smart charger will not only limit the maximum current but will charge your battery in the most efficient and shortest possible time. Placing batteries in parallel for any reason, is a sure way to shorten battery life.
Failure to follow electrical rules (or any safety related rules) in the pit is a sure way to get your team in trouble.

Re: batteries and chargers
 

The only way to (safely) charge multiple batters on the same charger is to use a special charger that is intended for that purpose. Normal chargers don't supply enough power to charge more than 1 battery at a time, and the wiring to split the current could also get a little tricky.

Charging battery's too fast is REALLY bad for the battery, it causes some of the cells inside it to short. That's why these super-heavy-duty chargers are hard to come across, and I won't recommend using them.

Best thing to do, in my mind, is use multiple chargers, 1 to charge each battery. On my team, we have about 12 competition batteries, and 12 chargers. This works, but it is expensive to buy 12 chargers. Also, with rumors of FIRST getting new batteries this year, it might be best to wait and see what batteries they get.

Re: batteries and chargers
 

Ok let's sum some points up here:

• Yes, it is possible to charge a battery quickly
• Yes, it is possible to run other configurations safely
• Yes, it is possible to charge multiple batteries at once
• Yes, it will damage your overall battery life.

Moral of the story? Be patient and protect your investment. It's not worth the risk of charging a battery really fast for one match and then having it kick out completely on you later in the day (when you really need it)

Re: batteries and chargers
 

Given the propensity of dangerous jury rigged battery charging setups, perhaps it is time for FIRST to have specific rules requiring the use of anderson connectors on battery chargers, and one-to-one hookups between batteries and chargers. If the rules are specific they will have to be followed...

Eugene

Re: batteries and chargers
 

I would like to see such a rule.

Re: batteries and chargers
 

ditto. Those uninsulated alligator clips are very close together when you clip them into the Anderson connectors, and I have witnessed arcing many times in the pits and even my own shop.

Re: batteries and chargers
 

I think this may all ready be a rule. Because we were a rookie team we borrowed chargers from parents on the team and at one of the tournaments they had us tape andersom conectors to them.

Re: batteries and chargers
 

It's not a rule, but like they said above, it ought to be.

The trouble is finding Anderson SB50 connectors with the right contacts for the smaller-gauge wire in a battery charger, or making a good splice using the 6 AWG leads on the ones you're given. Actually, I think B.G. Micro had the correct connectors at one point. And you can always order them from Terminal Supply or another vendor.

Re: batteries and chargers
 

Second this notion. We bought an X5 a few months ago......it charges 5 batteries at once...comes with Anderson Connectors and has only 1 power plug!!!!!

The unit was about $400....that's less than the $100 a piece you pay for kit chargers.

X5 Charger

Re: batteries and chargers
 

I like the rule and recommend this method to whoever will listen. You can make an adequate connection to the charger leads if you strip the insulation back about two inches and fold the wire several times to increase it's diameter. This method followed by a good soldering job will make good connection.

To quell any false hopes, fast charging a gell cell battery with anything other than a smart charger at 6 amps or less will not give you a full charge no matter how much current you try to push into the battery. Shortened life is only one problem that you may encounter, explosion and pit damage is another. If you choose to try and bypass acceptable charging methods, please do not come to a FIRST event.

Re: batteries and chargers
 

Your best bet is to use individual chargers. Also, put andersons on the end of the chargers to keep one from arc welding in the pits!