There is no need for complex algorithms when charging LiFePO4 cells.
All the chargers I have seen for these cells are CC/CV, which is simpler than a multi-stage lead acid charger.
One of the joys of running a lithium bank is that the charge efficiency is almost 100%. I have put 8413Ah into my bank, and I have consumed 8325Ah. Over the three years that I have had my cells, I have lost 1% of the energy I have put into the bank. 88Ah.
(What's interesting is that the cells are shipped partially charged, so the "missing" 88Ah might have gone into fully charging them the first time, making the charge efficiency better still).
Once the cells are fully charged (I charge to a conservative 3.4 volts per cell), all you have to do is keep track of the Ah consumed, and charge until you have returned that number of Ah to the bank.
I have found that these are simple cells to manage. All you need to do is keep putting back the energy you consumed. Any of the Coulomb-counting devices (I use a Link-Pro) will allow you to easily monitor the state of charge.
It doesn't matter what the charging source is, just be sure not to overcharge them.
-Tom
--- In electricboats@yahoogroups.com, oak <oak_box@...> wrote:
>
> OK, so this begs the question....
> Â
> I *KNOW* that I'm sure I *SHOULD* use extremely complex algorithms for charging - especially Li batteries.
> Though if you hook them up to solar panels, it's still probably basically just applying a trickle charge, right??
> Â
> Is there a well documented site that gives specifics for charging lithium batteries if we want to (for whatever reason) roll our own charger?  Is it safe to apply a low power source to a lithium battery and slowly bring it up to proper, fully charged voltage without any fancy algorithms?
> Â
> Sure, it would take a lot longer, and be very low tech.  But from a rumor I heard, Lithium batteries might not last so long taking the REALLY FAST charges anyway...
>
>
> ________________________________
> From: Roger L <rogerlov@...>
> To: electricboats@yahoogroups.com
> Sent: Sunday, April 21, 2013 10:16 AM
> Subject: [Electric Boats] Battery Chargers
>
>
> Â
>
>
> Yep, I got my first really smart charger a year
> ago and it is a marvelous thing....hooking it to a battery for a day gives me
> that same satisfied feeling that I get when the family car has fresh oil and all
> the filters changed.
> Â
> But for dealing with lead acids faking
> unchargeability nothing beats the old brute force charger that still lurks
> in our shop.  You know the type: it looks like an overweitht
> R2-D2 on wheels. Inside is a transformer the size of a melon,
> rectifiers held together with bolts!?!, and a big honking fan to keep it
> all cool. On the front panel the controls are simple: An
> on/off timer, an ammeter and rotary range switch.
> Â
> The monster doesn't care what it is hooked up to
> and is probably as comfortable doing light welding as charging a battery.
> Just the thing to light up a lazy battery shamming unchargeability.
> It's a charger from an older era
> ......
> Â Roger L.
> ......
> ..............
> ----- Original Message -----
> From: Carter Quillen
> >To: electricboats@yahoogroups.com
> >Sent: Saturday, April 20, 2013 9:01 PM
> >Subject: Re: [Electric Boats] Battery issues
> >
> >
> >Have to agree with you on the old style chargers. These new fangled electronic wonder chargers can be a pain when you kill your battery and want to bring it back from the dead.
> >Â
> >Carter
> >http://www.archemedesproject.blogspot.com/
> >
> >
> >
> >________________________________
> >From: oak <oak_box@...>
> >To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> >Sent: Saturday, April 20, 2013 10:39 PM
> >Subject: Re: [Electric Boats] Battery issues
> >
> >
> >
> >I had a similar issue with mine. Turned out I had a combination of problems:
> >Â
> >1) The AM/FM/Cassette radio on the boat wasn't completely "off".  I had botched the wiring on the "memory" wire (was too lazy to run a separate wire for that...). I would have thought that as long as the radio was "off", it shouldn't draw even a noticable amount of current. WRONG. When shore power went out, it was enough to take the 12V house battery down to zip. And once it was down below a certain threshhold, the charger refused to bring it back up again.  So.... Check to see if there's any current drain at all that you're not aware of when you think everything is "off".
> >Â
> >2) Check your charger.  Though - these days, it's harder to do since the chargers are so darn "smart".  The manufacturers for trickle chargers typically won't tell you their algorithm (at least not in an obvious place) - but it seems like they sense the voltage on the battery before they start charging. If the battery gets too low, the charger is smart enough to know not to mess with it (??!!).  I miss the days of chargers that just put out a current limited voltage no matter... (I'm sure THAT comment will raise some eyebrows - but at least it was a LOT SIMPLER back then to tell if the charger was good or bad...)
> >Â
> >Good luck!
> >
> >
> >
> >________________________________
> >From: Mike <biankablog@...>
> >To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> >Sent: Saturday, April 20, 2013 8:41 PM
> >Subject: Re: [Electric Boats] Battery issues
> >
> >Â
> >Sounds like the batteries are sulfating. IMO you really should consider a beefier three stage charger than a trickle charger. I'm using a Zivan NG-1 for bulk charging and sometimes a DUAL PRO 4 to top the individual AGM Â batteries off. My batteries are still going strong after five years. Perhaps a little more info on the batteries (type and size) and brand and specs of your charger would help the battery gurus here to give you more advice.
> >
> >
> >Capt. MIke
> >http://biankablog.blogspot.comÂ
> >
> >
> >
> >________________________________
> >From: "magicflyer@..." <potedenuni@...>
> >To: electricboats@yahoogroups.com
> >Sent: Saturday, April 20, 2013 12:29 PM
> >Subject: [Electric Boats] Battery issues
> >
> >Â
> >I have been experiencing battery issues. I have a 48v system (4x12 wet cell) on a fairly new trickle charger. After only a couple of months, all four batteries had to be replaced...wouldn't take or hold a charge. The new batteries have been in only about 6 weeks and already I am only able to get to 47.5v. I fear the new batteries are already shot. I have been having a problem with the shore power breaker tripping which leaves the boat with no power for several days at a time, but can't see how that would be damaging the batteries. Can anyone give me any pointers on common problems that might be damaging the cells? Thank you!
>
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