[Nathan Crabtree]

A little bit of background..... I have a 2005 1st gen insight (my second insight) with 96K miles. Bought it with a "bad" refurbished battery. The current battery had been replaced about 5 years ago but the previous owner let the car just sit to the point that the IMA stopped working prior to when I purchased the vehicle. I Installed a grid charger and I now grid charge the battery whenever the IMA light comes on and then pull the negative battery cable to reset everything (about once a month).

The car goes into auto-stop like it normally should. If you pump the brake it will auto-start, putting it into 1st gear also makes it auto-start. The only time it doesn't seem to work is if you let the car just sit so that the SOC decreases to the point where it should turn on automatically. When the car has between 1-3 bars left on the battery indicator the 12V battery light will come on and the engine won't turn on. If you put it in first gear quickly when this happens or pump the brakes it will restart the normal way. If you wait long enough I have to use the key and restart it with the backup starter (still showing 1 or more bars on the IMA indicator). All of this happens without any IMA light. Reset the BCM with no improvement.

Has anyone else experienced this? Were you ever able to solve the issue? It would just be a minor inconvenience except that I would like to leave the ignition on for an extended period of time with the engine toggling on and off as needed.

 

[eq1]

That sounds like normal bad behavior (or protective behavior) to me. If the car's in autostop and the IMA pack reaches empty, the DCDC will soon disable and it won't come out of autostop automatically. There's usually a brief window of time between 'empty' ('neg recal', BAT gauge plummeting) and DCDC disable during which it will come out of autostop with the usual interventions, such as putting it in gear. The 12V battery warning light is an indicator that you're past that window...

The ICE doesn't restart automatically to prevent draining the IMA pack - I think it says it's supposed to, in the owner's manual, but it doesn't do that. If left in autostop, you can drain the IMA pack until functionally empty.

I'm not really understanding what you're trying to achieve/do. I think the normal answer is, you need to keep your pack charged higher... You say you'd, "like to leave the ignition on for an extended period of time with the engine toggling on and off as needed." That sounds to me like you're expecting the car to autostart and autostop on its own, if left in autostop. That doesn't happen.

 

[Nathan Crabtree]

Thank you for your reply. I couldn't remember from my last insight if it would restart automatically from autostart due to a low IMA battery. For some reason I thought it did but maybe I was mistaken and it's been years since I would have used that feature. As for what I'm trying to accomplish.... I will be sleeping in my insight 4-5 nights a month come November-->? . I've pulled out the passenger seat and created a somewhat comfortable sleeping platform on the passenger side but was hoping to solve the power/heat side of things. My thought was to use a 12v heated blanket but that would require power and having the convenience of a reliable power source would be a plus. I'm familiar with normal precautions when it comes to exhaust fumes and ensuring that the air quality inside the vehicle is safe.

 

[Willie Williford]

A good sleeping bag would work just as good as a heated blanket. IMHO

 

[Nathan Crabtree]

A good sleeping bag would work just as good as a heated blanket. IMHO

True, I use a good quality sleeping bag but still become cold during the winter when out in Indiana weather.

 

[eq1]

hmm, that's a tough one...

First off, you can't leave the car in autostop and expect the car to restart on its own to recharge the battery/batteries... There's probably a way to hack the system, I'd bet, to make it do that, which would be cool. But that would take special knowledge and skills, time, etc. And it's never been done, or at least I've never seen that mod around here...

Secondly, ultimately you'd need some specific power/energy requirements data to be able to really figure out what might work and what wouldn't... i.e. How much power and energy do you think you'll need over a night?

I'm not sure what those electric blankets require, and how long it'd be on vs. off, for instance... My guess is you might have a 50W blanket on for 15 minutes per hour of use (i.e. that might be enough to keep you warm enough). If you used it for 8 hours, that'd be: 50W X (8hours/4)= 100 watt-hours... If powered via 12V system, that'd be: 100Wh/12V = 8.3 amp-hours. The total rated capacity of OEM Insight batteries is about 28Ah, but you might get...not even 50% of that for usage, since it doesn't charge totally full and it can't, or it's not good to, drain completely empty... Not to mention the Insight 12V charging system can often leave the 12V battery at a low level...

But, if these were close to the rough requirements, I think it's close to doable. If this were all you needed, I think I might at minimum look into replacing the 12V battery with a high quality deep cycle one. I don't know what capacities are available in what form factor/size, it'd be nice to find one that's like double the stock capacity, maybe around 50Ah, but the same size. I kind of doubt that exists, though... A related alternative might be an auxiliary deep cycle 12V battery.


The other thing I'm thinking is a mod to the DCDC converter wiring that enables it all the time. I can't remember exactly what that entails. I'm thinking you need to cut a wire, and then it will work but only if the key is turned to the II position. So, in this scenario, you'd turn key ON, Insight 12V system is activated, which itself requires about 65 watts, and is powered from the IMA pack via DCDC...

So say the power requirements are same as above, but you also need an extra 65 watts continuously: 65W X 8 hours = 520 watt-hours, plus the 100 watt-hours for the 'blanket' = 620 watt-hours. The pack itself as used and managed, typically, will only hold about 144V X 3.2Ah = 461 watt-hours, on a good day...

So it seems like you'd be better-off sticking to the 12V system via 12V battery alone. That 65 watt continuous load is a serious drawback.

It might be worth looking into the 'DCDC always-on' mod some more, maybe there's a way to get it to activate without having to power all the car's electronics... Off the top of my head, though, pretty sure that's not how it works, and pretty sure you couldn't do it easily - the IMA electronics need to be activated. At minimum, it seems like you'd need to create some auxiliary circuit that powered only the relevant electronics, like with key in the auxiliary position, power would go to 'the IMA electronics and DCDC circuit'... And my guess is even that 'circuit' would require quite a bit of energy, maybe not 65W, but probably at least a 1/4 of that, if not half...

I don't know, I'm not the resident electronics guru around here, I'm just the 'dreamer-dabbler'. I can think of a lot of stuff, imagine stuff, but have the skills and knowledge to implement like a fraction of it...

 

[Rainsux]

Wouldn't it be easier to carry a small generator? The car isn't designed to do what you want to do. Best case: You're stuck with both dead batteries. Worst case: you'll fry something.

Sam

 

[eq1]

^ I wouldn't think he'd need a full-on generator. I'd bet something pretty simple, like an auxiliary deep cycle battery, would be enough to keep him warm, take the chill out of the air in the cabin, enough to get some sleep. Of course it's hard to say, don't know how cold it will be and OP's cold tolerance...

I've slept in the car a few times, in sort of cold weather, maybe down to 40 degrees F? Or actually, on my way back from Insightfest last year, I slept in the car near Grant's Pass OR, and I think it got down to about 33 F degrees.

I needed to turn the car on at least... 3 times and run the heater to stay warm enough, and it was never warm enough for long enough. I did not sleep well (of course, sleeping across the front seats didn't help).

BUT, the equivalent of that turning on the car a few times - without actually having to do it - probably would have worked. It doesn't seem like a ton of energy would be needed. That ~50W blanket, maybe for 30 minutes per hour of usage? - I'd think that'd work. The blanket itself would keep the body warm, and the residual heat would in turn heat the cabin a bit - I'm thinking just enough to take the edge off...

I actually lived in a van for some years, too. Really, you just need a good sleeping bag and an extra blanket or two to get through the nights comfortably, at least in the Pacific Northwest (down to ~30F degrees in winter, usually). The only exception to this is when you're first going to sleep - it really helps to have a boost of heat when you're going to bed, warm the cabin comfortably, so you can actually fall asleep. Running the heater in the car would do it. Good sleeping bag and extra blankets get you through the rest... Crack a window or at least leave the outside air vent open to prevent too much condensation. Condensation can lead to some nasty stuff.

edit: here's another idea - perhaps having the equivalent of a bivvy sack in your passenger seat sleeping area would be prudent? Your body warmth will heat the air in the sack, enough to make it comfortable. The car cabin is pretty leaky, can be drafty and just gets cold fast. I used to crawl into the sleeping bag (mummy-type), cover head, and have a wool blanket over it all, but that can be claustrophobic to some. Also, make sure you're using a good thermal pad, like a therm-a-rest, or generally, insulate the floor under the sleeping area.

SUMMARY:
-insulate floor under sleeping area
-use a good winter-rated sleeping bag and have at least two extra blankets
-consider a 'bivvy sack' or equivalent covering over sleeping area
-make sure to ventilate cabin, crack a window, leave outside air vent open

-get a good deep cycle battery at least the size (~28Ah) of the stock one to replace stock
-alternatively: get a bigger deep cycle battery to replace stock
-alternatively: get a bigger deep cycle battery and create auxiliary 12V system
-supplement 'insulative' tactics with the minimum extra electric heat required and appropriate to whatever 12V strategy you choose.

 

[Nathan Crabtree]

^
SUMMARY:
-insulate floor under sleeping area
-use a good winter-rated sleeping bag and have at least two extra blankets
-consider a 'bivvy sack' or equivalent covering over sleeping area
-make sure to ventilate cabin, crack a window, leave outside air vent open

-get a good deep cycle battery at least the size (~28Ah) of the stock one to replace stock
-alternatively: get a bigger deep cycle battery to replace stock
-alternatively: get a bigger deep cycle battery and create auxiliary 12V system
-supplement 'insulative' tactics with the minimum extra electric heat required and appropriate to whatever 12V strategy you choose.

I like the idea of installing an auxiliary 12V battery. My current thought would be to install the auxiliary battery it in the rear storage compartment with the spare wheel. I'm thinking this isolator may work well and could be installed inline at the dc-dc converter.

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I don't know all things electrical though. Any thoughts? How do I ensure that I don't overload the dc-dc converter?

 

[eq1]

I'll have to look at this closer later. But, in general, I think it might work, at least in certain ways. Overloading the DCDC I don't think would be an issue...

I looked for a better manual but couldn't find one. If you see one, post it or a link (the "userguide" link at the webpage is just a warranty disclaimer). I don't quite understand what they mean when they say it "cuts in at 13.3V" and "cuts out at 12.8V." So, what's it doing between 12.8V and 13.3V??

What it looks like is you essentially have the batteries in parallel - with a switch in between on the positive cable. At first I thought the "cuts in" language meant that the auxiliary battery would be connected to the car's 12V system if the voltage is 13.3V or more. So, both batteries would charge if voltage is 13.3V or more, which is generally most of the time the car is running. OK... And it says it "cuts out" at 12.8V - so, if system voltage is 12.8V or lower, the switch is turned OFF, the auxiliary battery isn't connected. That seems fine in a car-running scenario, I guess.

So then, what happens when the car isn't running, or if the key is in the #1 position?

Start with car not running, key OFF. You can run your auxiliary load 'directly' off of the auxiliary battery, such as by wiring in an automotive 12V receptacle. The stock battery and aux battery will be connected if voltage is 12.8V or more, it seems. But once voltage drops below 12.8V, they'll be disconnected? That'd be OK, in terms of preserving the stock 12V battery. And you'd be able to run your aux appliance off the aux battery... That seems to achieve about what you want. Then, when you start the car in the morning, the stock 12V powers car electronics, the IMA bat starts the car, DCDC boosts output to ~14V, both batteries get charged. Also seems OK...

So now, what about key ON position 1? This is what doesn't really make sense (in addition to the 'what happens between 12.8V and 13.3V', which is a mystery). If you have key in position 1, you can use the radio, power something off the car 12V receptacle, etc. Both batteries will be in play - but only until voltage drops to 12.8V, it seems, at which point, the isolator disconnects aux battery from system. You end up running down the stock 'starter' battery... That's not what you'd want. Ideally, you'd be running off the auxiliary battery...

Anyway, that's about all the musing I can do for now.

 

[eq1]

I don't really have anything more to say about this today. Just that I don't fully understand the point of that device.

You should be able to do a similar type of auxiliary battery install - but skip the device and instead just install a big switch that you manually activate and deactivated as needed. Maybe that's the whole point of that device - that with it you won't need to do anything manually, but you also won't have the ability to have the key in the #1 position and run off of the auxiliary battery, at least that's my reading of the situation.

You might want to copy your post or make a new one and create a new thread with a different title, strictly about installing an auxiliary battery. Might get the attention of someone who has better advice.

edit: hmm, now that I think about it, you probably do need some kind of 'isolator' between the two batteries, beyond just a big switch, to help control the current exchange between them when voltages are very different*... It's been so long since I had/made a system like this, for an old van. But I did have an "isolator" between the starter battery and aux battery, and a single switch that allowed me to choose when the aux battery was in the loop or not... I also had an ammeter to the aux battery to let me know when and by how much the aux battery was charging...

* Not sure how much difference there'd ever actually be, though. My guess is not much, and that it wouldn't matter much. The stock battery will be around 12.8V, and you shouldn't be running your aux battery down too much, either. If the two batteries were in parallel, starter bat at ~12.8V, aux bat at maybe 12.2V, you flip the switch, you might get a blip of relatively high current, but otherwise the voltage difference is small and the voltages will quickly equilibrate... I think that's also part of the point with that device: I think it's meant to keep the voltages similar, so the control of current is in the similar voltages, not a diode/resistor setup of some sort that can sap energy...

I'd still be interested in seeing a manual/spec sheet if you find one. [edit: found one, I'll look it over: 12V 140 Amp Dual Battery Isolator & Full Size Automobile wiring kit]

edit: OK, I'm done, there's not a lot there, not many details/specs. It all sounds like I described earlier. They just expect that you aren't running auxiliary loads off the car's 12V receptacle, with Key in the #1 position. They say all auxiliary loads need to be powered directly from the aux battery.

 

[RonaldH]

I'll have to look at this closer later.

I’d suggest something like a jackery (portable power pack) which can recharge when driving via the cigarette lighter and alternately solar panels.

 

[Nathan Crabtree]

This really helps! Thank you! I've looked at the jackery products and am definitely considering that option as well.