Date: Sun, 13 Mar 2011 18:00:29 -0700
Reply-To: Al Knoll <anasasi@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Al Knoll <anasasi@GMAIL.COM>
Subject: Re: Auxilliary batteries
In-Reply-To: <4d7d4233.1d4de50a.3591.ffffec0c@mx.google.com>
Content-Type: text/plain; charset=windows-1252
The Honorable Rocket J. Squirrel uses a charger made in UT. He's a member
of our fine society of goofy vanagonighties,
On Sun, Mar 13, 2011 at 3:12 PM, David Beierl <dbeierl@attglobal.net> wrote:
> At 05:47 PM 3/13/2011, Gilles H Turmel wrote:
>
> To my understanding the gel type battery will only give me higher life
> expectancy of the battery with the same autonomy as acid type. Is that a
> good assumption?
>
>
> Gilles, try a different word for 'autonomy' or give us the word in
> French...
>
> In the mean time - in order to get good life from any battery used for
> deep-cycle applications, but *most particularly* from AGM and gel type
> batteries, it is necessary to follow the correct charging regime which is
> not possible with automotive-type voltage regulators. I would strongly
> recommend to use either of these types only if you will also use the
> necessary equipment for charging and for monitoring discharge. It happens
> that my brother is making an installation of AGM batteries in his boat, and
> in the course of discussing this with him I collected some charging regimes
> from various AGM battery manufacturers which I will quote below. Gel
> batteries will have similar requirements which also can be obtained from the
> individual manufacturers.
>
> Yours,
> David
>
> Optima Yellow Top, cyclic application:
> Cyclic Applications:
> 14.7 volts, no current limit as long as battery temperature remains below
> 125°F (51.7°C). When current falls below 1 amp, finish with 2 amp constant
> current for 1 hour.
>
> Lifeline AGM, all:
> The following charging voltages are recommended for maximum battery life
> for all Lifeline models.
>
> Charging Phase 12 Volt Battery
> Bulk/Absorb 14.2v - 14.4v
> Float 13.20v - 13.40v
> NOTES:
> 1. Use midpoint values for most applications. Lower voltages may be
> suitable for light-duty applications and higher voltages may be suitable for
> heavy duty applications.
> 2. For 24 Volt Systems, multiply 12 Volt setting by 2.
> 3. Charge voltage should be adjusted if battery temperature varies by more
> than 10°F from 77°F. Consult website for further guidance (www.lifelinebatteries.com).
>
>
> Conditioning/Equalizing Charge: 15.5 volts for 8 hours
> Conditioning/equalizing should only be done when the battery is showing
> symptoms of capacity loss. If conditioning/equalizing is necessary, first go
> through the normal charge cycle. Once the battery is as fully charged as
> possible, start the conditioning/equalizing charge.
>
> For maximum battery life, a battery must be recharged to 100% capacity.
> Recharging to less than 100% may result in premature battery failure.
> Lifeline batteries are not covered under warranty if they are not recharged
> properly. For more information, please refer to our warranty policy.
>
>
> DEKA:
> The charger must be temperature-compensated to prevent underor
> overcharging due to ambient temperature changes. (See Charging
> Voltage vs. Ambient Temperature chart on page 11.)
>
> Use only “voltage-regulated” or “voltage-limited” chargers.
> Standard constant current or taper current chargers must not be
> used. The voltage must fall in the range of the chart on page 11.
> Almost all applications require temperature sensing and voltage
> compensation. Beware, many chargers measure the ambient
> temperature which could be significantly different from the battery’s
> internal temperature.
>
> Temp. Charge Float Temp.
> °F Optimum Maximum Optimum Maximum °C
> . 120 13.60 13.90 12.80 13.00 . 49
> 110 – 120 13.80 14.10 12.90 13.20 43 – 49
> 100 – 110 13.90 14.20 13.00 13.30 38 – 43
> 90 – 100 14.00 14.30 13.10 13.40 32 – 38
> 80 – 90 14.10 14.40 13.20 13.50 27 – 32
> 70 – 80 14.30 14.60 13.40 13.70 21 – 27
> 60 – 70 14.45 14.75 13.55 13.85 16 – 21
> 50 – 60 14.60 14.90 13.70 14.00 10 – 16
> 40 – 50 14.80 15.10 13.90 14.20 4 – 10
> . 40 15.10 15.40 14.20 14.50 . 4
>
> MK Batteries:
> *AGM Battery Charging
> STAGE END CONDITIONS ERROR
> Bulk Stage I1
> *Maintain Current <= 30 A per 100 Ah C20
> Typically, Constant Current, but Constant
> Power, or Taper Charge Permitted
> End when voltage = 2.40 to 2.43 V/cell (20°C)
> Max time (h) = 1.2 * DoD (Ah) / Avg. Current (A)
> If Max time is
> exceeded: STOP
> *Absorption Stage V1
> *Maintain Constant Terminal Voltage
> (Adjusting only for changing battery
> temperature)
> Voltage = 2.40 to 2.43 V/cell (20°C)
> Without the optional accelerated finishing stage,
> maintain charge until current acceptance drops by
> less than 0.10 ampere over a 1 hour period
> Max Time: 12h
> With optional accelerated finishing stage end
> when current = I2
> Max Time: 6h
> If Max time is
> exceeded: Goto next
> stage
> If Current exceeds
> 8 A after dropping
> below 6 A: STOP
> *Optional Accelerated Finishing Stage I2
> *Maintain Constant Current:
> 1 to 2 A per 100 Ah C20
> Charge for 1 to 4 hours based on Ah accumulated
> in first two stages:
> <25% of C20 – 1 hour
> 25% to 50% of C20 – 2 hours
> >50% of C20 – 4 hours
> If Voltage exceeds
> 2.80 V/cell: Goto
> next stage
> *Optional Float Stage V2
> *Maintain Constant Terminal Voltage
> (Adjusting only for changing battery
> temperature)
> Voltage = 2.25 V / cell (20°C)
> No time limit
> This step is generally unneeded if
> (1) zero load is present when device is not in
> operation, and (2) device duty cycle does not
> include periods of non-use exceeding 3 months.
> To compensate for battery temperature not at 20°C, subtract 0.005 V/cell
> for each 1°C above 20°C; add
> 0.005 V/cell for each 1°C under 20°C.
> Applies to East Penn’s 8A Line product.
>
> You can find all this stuff better formatted and more complete on each mfrs
> website. Google agm batteries and one of the top results will be a list of
> brands.
>
> My point is that the makers care enough to specify very rigorous charging
> regimens including continuous battery-temp measurement and
> bulk/absorption/float charging, either unconditionally or for all cyclic
> applications. Some (Optima for example) say if you're using it as a
> starting battery you can hook it to an automotive-type regulator within x
> voltage limits. Some (Lifeline, for example) do not allow that under any
> circumstances and will void your warranty if you do it (more correctly, if
> you don't keep the thing correctly charged they won't honor the warranty;
> language is above in the Lifeline section).*
>
> *Incidentally, the one that mentions the harmful qualities of ripple then
> goes on to describe a test procedure that won't tell you anything about
> ripple. But every digital voltmeter I've ever used, the AC ranges will
> reject DC and will be good up to 400 Hz or so, so if you have one with a 2V
> AC range you can directly measure LF ripple on the charging line.
>
> It's your call; they're your batteries. But I want to say wake up and
> smell the coffee - the equation is clear: if you can afford AGM batteries
> then you can afford the right gear to take care of them. People who say
> that the three-stage regulators are ridiculously hard to wire up have fallen
> victim in some way to the "electricity is magic" myth. Slow down, read the
> manual/hookup diagram a few times until you understand who does what to
> which. Once you understand what's going on, the physical wiring is no big
> deal. Off the top of my head, you've got, minimum:
>
> Temp sensor to battery post (twisted pair)
> +12 supply from ignition switch
> Power ground (B-)
> Current source (or sink) to alternator field
> +sense to B+ at battery
> -sense to B- at battery (may be combined with system ground, above)
> sense input to drop to float voltage if halogen lights are running, since
> they're intolerant of high voltages. With more and more LED lighting
> halogens are probably dodos at this point.
> Analog or digital adjustment for base charge voltage(s) before temp
> compensation
> Analog or digital adjustment for absorption charge time, since it's not
> economically feasible to get the last few watt-hours in given the cost of
> gasoline.
>
> Optionally:
>
> Pushbutton to immediately drop to float until next restart
> Remote indicators for what mode the regulator is operating in and for error
> conditions.
>
> Further fancies:
> The device may incorporate automatic charge switching between banks,
> automatic paralleling of banks while charging, automatic solar charge
> controller, instrumentation, maybe bunch of other things. Each of those
> things will have its own set of wiring requirements - consider them
> separately and they won't seem so complicated.
>
> :)
> d
>
>
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