Car Battery Charger
Email question: Can I use a regular car battery charger to recharge deep cycle batteries, or do they need a special kind of battery charger?
Answer: A regular car battery is 12 volts, and if your electric car has 12 volt deep cycle batteries, the 12v battery charger will work just fine...
...on ONE battery at a time.
Think you can handle a bad boy?
The simplest battery charger is a homemade "bad-boy" charger. It just takes current from your wall socket and zaps those electrons back into the battery. On the one hand, it's cheap and straightforward. On the other hand, like any other bad boy...
...this charger requires constant attention; )
Those expensive batteries you just bought have very specific charging needs. They'll need an initial charging voltage of 14.2 to 15 volts during the "absorption phase", and then when they've reached 80% of their full charge capacity, they'll need the voltage to be cut back to no more than 13.8 volts for the "float phase". This is to prevent overheating the batteries, excessive gassing (lead-acid batteries produce hydrogen and oxygen gas as they charge), and permanent damage.
Can you do this yourself with a bad boy charger? Sure. Remember that the batteries won't charge at the same rate, though, so you've got to mind each of them (We'll talk about balancing your battery pack another day). And you've got to be just as attentive during the Super Bowl with a houseful of beer-guzzling lunatics as you were on that zen-and-green-tea day you charged those batteries for the first time.
Tricky.
Smart, so you don't have to be.
There IS a better way.
A smart charger will automatically sense when your batteries have reached the "80% charged" mark, and cut back the voltage delivery as appropriate. A cheap smart charger does this by sensing the temperature of the battery; the temperature starts to rise after they hit the magic 80%. An expensive smart charger uses a voltage feedback sensor, so is much quicker to respond, which is better. Your 1800 dollar set of batteries will thank you for your generosity; ) When your batteries are fully charged, the smart charger will stop - so you can just plug in your smart charger, attach the cables, and forget it.
About that "one-at-a-time" car battery charger...
The 12v battery charger you get at the auto parts store - even a really good one - will only charge one battery at a time. If you've got a 120v system, you don't want to get 12 battery chargers! What you need for your electric car is a series charger.
And the most popular electric car battery charger is...
The Zivan NG3.
This charger is made in Italy and readily available in the US. Just let them know when you order your charger what kind of batteries you've got, what your car's system voltage is, and the input voltage (where you plug it in to the wall - toaster, or dryer?).
It's relatively inexpensive, but perfectly adequate for practically all electric car applications.
The second most popular electric car battery charger, according to the ev album at austinev.org is...
The Manzanita Micro PFC-20.
Very popular, and the "PFC" means "power factor correction". These PFC chargers cause otherwise perfectly reasonable electric car builders to drool, for some reason. If I'm reading the very dense language of Wikipedia correctly, PFC means that through some strange electrical wizardry and tomfoolery you can stuff more power into your battery pack than with some other charger.
Another benefit? With a PFC charger, you can sip juice from the AC main or guzzle it, depending on what's available. From Beepscom: "The key to polite opportunity charging is to be able to share outlets with other equipment and make efficient use of limited current. The PFC line of chargers have a throttle to allow the chargers to be turned down to operate on very limited power sources such as small generators."
More expensive than the Zivan, but worth it.
Oh, one last thing: both of these chargers are designed to be used with lead-acid batteries only. NiCd, NiMH and Li-ion batteries each require their own kind of chargers, which I'll talk about another day.
Have A Question About Battery Chargers?
Ask a question about battery chargers for electric cars, get an answer, and help others by contributing to the discussion!
What Other Visitors Have Asked
Click below to see contributions from other visitors to this page...
Military justice is to justice what military music is to music. - Groucho Marx

Return from "car battery charger" to conversions page
Go from "car battery charger" back to the homepage

|