New Lithium Batteries - Need New Battery Charger?

by David M.

Do you really have to have a lithium ion battery charger if you put lithium ion batteries in your EV? It's time to replace the batteries in my conversion, and I'm thinking of making the switch to lithium ion batteries. I paid good money for that charger, though, and it doesn't need replacing. Do I have to go and switch out my charger if the lithium batteries have the same voltage as the old batteries?

Hi, David -
No, you don't necessarily need a special charger.

What you do need is a charger that is adaptable to a new set of battery requirements. Your lithium pack will have a BMS to interface with (LiFePO4 distributors generally require BMS to warranty their batteries) and you'll need your charger to know how fast to offer electrons to the pack, when to slow down, how warm the batteries are getting, and when to stop charging: the charging algorithm. It's different for different battery chemistries.

If you've paid for a high-end charger, contact the folks you bought it from and tell them what your situation is. They'll help you program your old charger to meet your new needs.


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Does an Automotive Battery Charger Work for EVs?

by Walt

A regular automotive battery charger costs around 50 bucks, even for the smart kind with jump capability and trickle rate at the end. So tell me, why should I pay three grand for a Manzanita Micro PFC-30 when all it does is charge 120 volts (my car's got a 120v system) instead of 12? I'm no Einstein, but even I can figure out that 50 times 10 is not 3000.

I'm sure there's a good explanation, and I'm patiently waiting to hear it.

Hi, Walt -
Darlin', I can't argue with your logic. You're right. And you can charge your batteries with anything you want. Plenty of folks who convert their cars to run on batteries have kinda run out of money at the end of the project...(um, is this you, too?)

...and think to themselves, "You know, all I've gotta do is get those electrons outta my wall and into my batteries. How hard could that be??"

The answer is, it's not. And if you want to get ten of those trickle chargers and hook up each battery to a charger, be my guest. Here's an article I've written about "bad boy chargers" to get you started.
But think about this: You spent a LOT of money for those batteries. And you could cook them over-easy in a second (or less) with a simple charging mistake.

Expensive chargers, like the very worthy Manzanita Micro that you mentioned, are always thinking about the health and welfare of your very expensive batteries. It is designed to dump a lot of wall-juice back into your battery pack, over and over and over, without damaging either itself or your precious Trojans.

Additionally, the Power Correction Factor allows you to sip juice or gulp it from your wall outlet, which is, in the immortal prose of some clever EV writer somewhere, "the key to polite opportunity charging." If you're at a buddy's ancient house with equally ancient wiring, you can plug in without burning his house down or popping his breaker.

If you're at your modern office building, you can download electrons as fast as your batteries can receive them. In practice, in everyday life, you'll LIKE this feature.

It's up to you, Walt. If you're only going to charge at home, you don't mind a little risk, and you've got a dedicated circuit so you don't trip your circuit breaker, by all means line up the ten sisters and let 'er rip.

Me, personally? I'll take the Manzanita Micro. It's the most sensible thing I've ever done with three grand.


P.S. If you're using LiFePO4 batteries...

You need a lithium charging algorithm. Lead and lithium don't charge the same. Your automotive battery charger is set for lead, not lithium. That Manzanita Micro? Programmable!

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