12V Battery Issues

From John Wayland at the Insight Owners group on Yahoo!

I am not sure what the problem is with replacing the battery with the 75$ Honda one?

The problem, besides being an ugly, generic black hunk (instead of the clean looking factory Japanese battery), is that it's far larger and heavier than it needs to be, and it's of questionable build quality...it looks 'American', like it belongs in an Oldsmobile, not the high tech Honda Insight. Paying $75 for such a low tech, out of place battery (it's really worth about $25) is contrary to common sense.

I'd be more concerned with additional accessories overloading the main 80 amp fuse than draining the battery.

Who has reported that they do this? Most everyone who installs a powerful after market stereo kit, knows better than to do this, and instead, goes straight to the battery's terminals, bypassing this 80 amp circuit. As far as draining the battery, when in good health and used regularly, the stock 27 ahr battery easily runs a good sound system for an hour without any charging help when played at fun volume levels, and even longer when played at quieter levels....less of course, when played at LOUD levels.

I originally added a 200 watt in dash stereo using the existing wire harness with no problems.

Your example of this as some kind of high current load, is curious to me. These head units only pull a max current of about 9.5 amps, so of course the stock wiring easily handles this.

Take a close look at that '200 watt' stereo, and you'll find it's not even close to being a real 200 watts in its output power, and in fact, it doesn't even draw that level from the battery. Most all of today's 'high power' in dash head units boast this 200 watt level, and it's simply BS that goes unchecked. Even the high quality brands like Sony, Alpine, Eclipse, Kenwood, Pioneer, JVC, etc., resort to this BS output rating on their head units. For some reason, they don't do it with their outboard amplifiers (though the off brands still do), but it seems like 'anything goes' when it comes to making ridiculous claims for head unit output power....allow me to clarify.

Actual, real watts are easily calculated by a simple formula.... amps X volts = watts, plain and simple. To figure the absolute maximum real watts a device consumes (always more than what it can produce, by the way), look at it's input power fuse....on a 200 watt head unit, its just a 10 amp fuse! Now, take the maximum voltage of the car, in the case of the Insight, its about 14.2 - 14.3 volts while the DC-DC is jamming in the juice. Let's be gratuitous, and use the highest voltage figure of 14.3V. This then works out like this....14.3V X 10 amps =143 watts.

However, if you really run at the full 10 amps, the fuse will blow, so manufacturers put in a fuse with at least a tad bit of headroom, otherwise, every time you cranked it up all the way, the fuse would blow, and this of course, is not the case. So a head unit with a 10 amp fuse, most likely, draws a maximum current of, say, 9.5 amps. This now works out like this.... 14.3V X 9.5 amps = 136 watts. Taking this one step further, when played with the 'ACC' position and with no DC-DC charging and just the 12V battery supplying power, it looks like this.... 12.7V X 9.5 amps = 121 watts. So here we are now, with a head unit that draws anywhere from 121 watts to 136 watts, so if it were 100% efficient (NOT), it would be 'possible' for it to make a max power of 136 watts...of course, I'm being silly, because I know that this isn't possible. In fact, the class AB IC chip style amps inside a head unit, are at best, 50% efficient. 50% of 136 watts is just 68 watts...but wait, there's more! The head unit has illumination, motors, and other electronic circuits that need power, too, so part of that 136 watts is pulled away by these devices' current consumption. The CD drive motor is very efficient, as are the LEDs that are used for most of today's head unit's displays, and the electronic circuits are all real efficient too (with exception to the output amplifiers), so let's say that 10 watts is need for these things....now we have just 126 watts of max. input power available to run the four audio amps inside the head unit, and at 50% efficiency, this then is a mere 63 watts, that divided by four (FR, FL, RR, RL) represents a whopping audio output of 15.75 watts per channel...even less when playing on 12.7V battery power alone...so much for that 200 watts of audio power! Doubt this? Read the specs of your head unit's owner's manual to see their claimed 'RMS output power'....most are around 12-15 watts per channel, but some even continue to lie in this area as well.

Sorry I digressed, but my point is, that saying you installed a 200 watt head unit, as an indicator of a 200 watt power draw, is not valid. Most likely, it's a 100-135 watt draw at its loudest playing volumes, and you're getting maybe 60 watts to 4 speakers, 30 watts if you run a pair of them, and really, about 10 watts per speaker when turned down to a level where the system plays at clear, lower distortion levels.

Now I did do some modifications for the 300 watt power amp, fog lamps, and running lamps, and rear view camera system and E-RAM intake blower. I installed a separate battery, fuse box, wiring (to isolate these from the factory system) and added a accessory outlet the kind with leds for monitoring battery condition, mounted a solar panel on the hatch glass. Then tied this in to the Honda system after the load sensor and 80 amp fuse. The system is isolated by relay and fused at 30 amp. I have had this system in place for about 50 k with no problem.

Not trying to rain on your parade here Mike, but that amp you've got can't be a real 300 watts of audio power if you are using a 30 amp fuse to tie it to the Honda's system. A 50% efficient 300 watt outboard amp (unless it's a class D type) needs 42 amps to make its full output power from a 14.3V source...this would instantly fry that 30 amp fuse. Unless you never turn it up very loud while you are driving with the secondary system being charged by the car's DC-DC, this just doesn't work out mathematically. What size is (are) this amp's power input fuse (fuses)?

I 'am' interested in that E-RAM intake blower! Care to elaborate on what you did, who makes it, how much current it takes to spin, and what effect it has? Does it produce noticeable and measurable boost pressure?

Replacement battery

OK boys and girls, good news from your roving battery guru...the highly sought after, direct drop in replacement , Japanese-made, factory looking 12V battery for your Insight has been found! The best part, is that it's of the deep cycle variety and is a beefy 35 ahrs.

About the typical 'dealer replacement' Civc type battery, I had written:

The problem, besides being an ugly, generic black hunk (instead of the clean looking factory Japanese battery), is that it's far larger and heavier than it needs to be, and it's of questionable build quality...it looks 'American', like it belongs in an Oldsmobile, not the high tech Honda Insight. Paying $75 for such a low tech, out of place battery (it's really worth about $25) is contrary to common sense.

Man, I'm excited after what I just held in my hands, this beautiful 'GS' battery made by Japan Storage (this make is often factory equipment in Toyotas and Nissans). Like the Furukawa battery, it has the same factory Japanese build quality and look, with a translucent white main body, the 'low' and 'high' water level marks, and the tidy black top.

It wasn't easy ferreting this battery out of hiding, as these guys at first, did the same thing to me that the dealers do, that is, they pushed a boring, black, Buick-looking brand X battery at me, yes, that long and heavy 'merican made Civic replacement type...argghh! I opened the hood of my still-in-showroom condition Insight and showed them the difference, but they still didn't 'get it'. I talked their ears off about Japanese quality, the way the battery looked and presented itself with the translucent white case, its clean markings, its tidy top, its immaculate seams, etc., and then reluctantly, I was led back into the warehouse. We still had issues with each other during battery tech discussions, and I was kind of talked down to, even as I explained my background in EVs and battery powered machines...he still didn't get it. After I saw the pallet of GS batteries. I knew we were on the right track. We went back into the office, where his 'I know more about batteries than you do' discussion continued. We argued about the differences between SLI and true deep cycle types of batteries, and as I was resting against the customer counter and looked through it's glass top at the battery brochures showcased beneath, I pointed to the tri-fold color layout for Optima Batteries that featured one of my EV conversions and said, "See this...it's me!" I gave him a blow by blow description of the car, gave him some pointers about Optimas, Hawkers, AGM construction, and nickel zinc technology...after that, he considerably mellowed and the dialog became more of a 'one on one' basis, and we started to make some headway as he actually listened to what I was trying to describe to him in the way of a 'direct factory like' replacement battery. Back out to the GS pallet we went, and after digging through battery after battery, we found it!

It is a direct drop in (are you listening, Dick?) with identical dimensions (7.8 inches high and 5 inches deep)with the exception, that like the battery for the CVT version, it's a tad bit wider, in the case of this GS battery, it's 7.7 inches wide (the 5 speed's is 6.5" wide, the CVT is 7.25" wide). This wider size accounts for the greater ahr capacity with just a small increase in battery weight. The 5 speed is a 27 ahr, the CVT is a 30 ahr, and this GS battery as stated, is 35 ahr. The battery weighs approx. 21 lbs...substantially lighter than that funky black generic Civic sized thing dealers try to push off on us. The terminals are in the correct spots, too.

I found it (just one in stock) at a local battery distributor here in Portland, Northwest Battery Supply. They also have a GS brand Prius replacement battery as well, complete with that car's weird small sized terminals.

Here' the Northwest Battery Supply part number and info:

# 2/5400
rated at 274 CCA
reserve capacity at 52 minutes

They can be reached at (503) 232-9002

Note that the cranking rating is about the same as the smaller stock 26 ahr battery...that's because this battery is a deep cycle type, and deep cycle types always have a lower CCA than an SLI type of the same size and weight. The fact that it is a deep cycle type is great news for those who play their stereos with the ign. key off...thisbattery will love this action!

Anyway, there's the scoop. I am told that GS has a warehouse in the New York area, and I imagine any other 'competent' battery distributor can find and get one of these nice batteries for anyone. The Northwest Battery Supply guy I talked with, told me they only had this one battery in stock, and that they normally have to place a 200 piece order to Japan Storage to get new batteries in, making it unlikely they will have more in stock right away, once this battery goes out the door, just so you know.

Battery Types and Cycling

For those of us who don't normally deep cycle our Insight batteries (e.g., by playing a stereo with the ignition key off), does a deep-cycle battery offer any advantage/disadvantage when a battery is normally kept almost fully charged as is the case with many (most?) Insights?

No. You are fine with just the none deep cycle, standard SLI type battery (starting, lighting, ignition).

Does a monthly 25% discharge (e.g., by leaving headlights on for 30 minutes) take advantage of whatever a deep-cycle battery offer over other types?

No. Deep cycle batteries have the advantage of being able to be pulled much farther down in the capacity, say 50%-80% of their full rated capacity, hundreds of times, without damage. They have thicker plates that handle this cycling well, but make the battery heavier, cost more, and cause it to deliver a bit less instantaneous high current power than their lighter counterpart SLI battery can.

In contrast, SLI type batteries don't like being deeply discharged. A shallow 10-25% 'depth of discharge' is all they need, less of a discharge is even better, if it's a regular thing. The monthly 25% discharge thing simply keeps everything active within the battery and keeps the capacity up. If you deep cycle this kind of battery, you do harm to it and drastically shorten its life....5-10 deep cycles and it's time to throw this type of battery away.

For quick bursts of power, an SLI type is superior to a deep cycle type, in that with their thin plates and overall lighter weight, they can dish out high power easier while weighing and costing less. Even though quick high power bursts seem like they would take quite a bit of a battery's capacity, they really don't and only represent a small depth of discharge. If this same battery is subsequently charged right back up, it's in its happy zone and gives long life with thousands of shallow high energy cycles....I've just described the role of a typical car's starting battery. Take this same battery though, and put it in an Insight, and it never sees any type of high current discharges, never sees anything really resembling a discharge, but, it is always on a relatively high float charge at 14.2-14.3V while the car is on...this is a prescription for a battery that will slowly lose capacity, due to lack of exercise and over-charging.

Both deep cycle and SLI types are damaged if you take them beyond 100% capacity and bring them to their knees. The rule of thumb, is that under a mild discharge, say 25 amps, when the battery hits 10.5V, its dead.

Would we be better off with a different type of battery?

No, not under the described conditions you outlined, the SLI type is fine. For those who do play the tunes on battery power alone, or those who for some reason like to use the headlights a lot to light up areas at night, and for those who may leave their Insights sit for a month at a time, a deep cycle has the advantage of being able to easily withstand high depth of discharges repeatedly.

The particular battery I have located, seems to be a wonderful solution, in that it covers all the bases. It first and foremost, looks like a factory battery and is made by a high quality company. It has the same cranking rating of the stock SLI battery, it isn't too porky in weight, it's nearly the identical size, it has 8 more ahrs of overall capacity, and, it is a deep cycle type, so it works far better than the stock battery at playing a stereo for long periods of time while being pulled down to high depth of discharges...for the same reasons, with its higher capacity to start with and with deep discharge capability, it can also sustain the small parasitic drain of the car's 12V memory circuits better while your car is left parked for a month or so.

When we first began to drag race electric cars, we all used what we had been used to using (my, that's a lot of uses), in that we had large battery packs made up of deep cycle batteries. These types of batteries are absolutely imperative to use in a street EV, and their deep cycling ability is the very basis of how an EV works for years and years on the same battery pack. However....what we found, was that we were packing way more weight than we needed to go quickly and fast down a quarter mile blast. Yes, we could race all night long, but our ETs weren't anything to write home about. Many of us figured this out early in the game, and switched over to SLI type car batteries. This lightened the pack by hundreds of pounds and at the same time, gave us batteries that loved to dish out very high currents quickly...the ETs dropped and the trap speeds rose! We still had far more battery capacity than we needed for the 1/4 mile blast, and so we started to experiment with smaller SLI batteries that we could use larger numbers of, to get to even higher voltages....the ETs dropped and the trap speeds rose! The low ahr packs were dump charged in minutes between runs to bring them full again. There came a point though, where the batteries got too small, and after a quick run down the track, the little fellers were exhausted and had been subjected to a deep discharge, so now we were going fast, but the battery packs were good for two race events, then we had to throw them away (recycled, of course). Then we discovered Hawkers, small deep cycle sealed AGM batteries that yet, could dish out huge currents and act like an SLI type. I've had Hawkers last 5 years of EV drag racing!

When Formula Lightning hit the scene (high speed road race type electric Indy style cars), the Red Top Optima starting battery (SLI) ruled over it's street going EV battery brother, the Optima Yellow Top. Why? Because in the same exact size case, it weighed 39 lbs. vs 45 lbs., it had more CCA's at 800 vs 750, and because there was major battery company sponsorship, no one cared that after a few races, the batteries had been deep cycled to death and were throw-aways. The same Red Tops though, would never be considered for a street EV...the Optima Yellow Top (called YT's within the EV crowd) is far superior with its 300 cycle life and the ability to be repeatedly taken to 80% discharges...at 50% discharges, they last closer to 500 cycles.

The primary difference between a 'starter' battery and batteries under constant float (usually refered to as 'deep-discharge') has to do with the plate design. Starter batteries have more plates per cell (but thinner, so they can fit the same case) to allow a higher instantaneous current output for the extremely high cranking amps needed by automobiles. Deep-discharge batteries have thicker plates. The reason you don't want to overly discharge a starter battery is that when you recharge it from deep discharge, those thin plates will heat up and sometimes warp on the edges, and touch each other, thus shorting out. While the deep discharge battery can't compete on instantanious output current, they can be discharged 'deeper' and then safely recharged because of the thicker plates.

Now. This is important. Neither type handles overcharging. Period. More batteries are killed by overcharging than anything else.Your battery makeup is usually either a flooded (wet) cell, a gell-cell (sealed), or an AGM (glass mat). Each has slightly different requirements but most are as follows;

  1. The battery is charged when it reaches about 12.6 volts.
  2. You charge a battery by giving it a higher voltage than it will eventually show. The higher the charging voltage, the faster the charge. (to a point of destruction)
  3. Starting a car drains a battery fast, so an automobile will try to put somewhere between 14.3 to 14.7 volts into your 12.6 volt battery in order to charge it fast.
  4. In a typical car, the battery is seldom fully charged, especially in the cold regions, so this is usually a good scheme.

Now the problem. What if the battery IS typically full? You kill it by overcharging! (and to a much less degree, by not cycling) Batteries designed for float charging are not especially resistant to overcharging either. On the contrary, they require significantly more sophisticated charging schemes, not the least of which is...float chargers are designed to put a maximum of 13.8 volts onto the battery. (13.65 if you are trying to make the battery last longer) Any more than that and the excess turns to heat, boiling away the electrolyte, warping the plates, and other bad things.

By the way your AGM is designed to take about 14.38 volts initial charge tapering down to 13.38 volts for 'float'. That is, once its charged to 80-90%, charge voltage needs to drop to 13.38 to avoid shortening battery life.

I wish I had a clever schematic for keeping your battery alive, but I'm sorry to say your plan may have only minimal benefits unless you can find a way to keep that charge voltage down.