Do you think this could be made to work as a battery pack?

thomas-dash

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Dash Cam
Viofo A129 Pro Duo 4k, Viofo MT1
I think I’m going to buy a battery pack to get it off the main car battery and hopefully get additional parking mode coverage since I’m not driving my car as much. Additionally, I’m planning on adding a second 2-channel dash cam.

With Cellink NEO I would need to buy two of them to get around 25 hours out of each camera. This would be over $600 compared to something like below which is less than $300:

https://www.amazon.com/gp/B08P5SFV4D
Due to its size, it would most likely have to go in the trunk and be strapped down really well to prevent it from becoming an eight pound projectile in the event of an accident.

An added benefit is that it would be more versatile than a regular battery pack.
 
With it being an Amazon link, I suspect I’m looking at something different to you!

The link takes me to something that looks good, however the charge rate is a little low and appears to require an additional charger that may be hard to obtain for a car. May be fine for your circumstances though.
 
This is the description of the item I was looking at:

“GOLABS Portable Power Station, 299Wh LiFePO4 Battery Backup, PD 60W Type-C Quick Charge, 300W Pure Sine Wave AC Outlet Solar Generator Power Supply for Outdoor Camping Fishing Travel Emergency CPAP (Orange)”

I think it comes with a 12 volt charger car charger. However, if it didn’t, or charged too slowly, I could just buy a second one and swap them out to charge in the house. this assumes I’m satisfied with the performance of the first one I buy.
 
If I'm looking at the right thing then I see it appears to have a 12v input which is nice, or a PD input.

What charge rate you actually get I'm not seeing except in the reviews it says from AC "It charged around 45-46W via display.".
If that is enough for you then fine, just don't expect it to charge to full during a 10 minute drive, it is going to take about twice the time of a Cellink Neo for the same amount of charge, but of course it is a lot higher capacity so actually needs far longer.

Reviews look good, not that you can always trust Amazon reviews, but when they give useful details they tend to be decent.
 
Don't waste your money on these pre made battery packs. They have a cheap battery, undersized, plus things you don't need.

Buy an AGM or gel battery or batteries to fit the available space in the car and a DC-DC charger.

I have four 26AH batteries around the car as that was the best size for my situation. One larger batter is cheaper. With lead acid in general aim to only use 50% of its AH before recharging. Every now and then a heavy discharge is ok but charge up ASAP.

If you want add a solar panel. Either a 10 watt panel with diode to trickle charge or larger panels with a solar controller.

(Top with additional heatsink is a personal modification to my MPPT. Bottom, 2 DC-DC controllers mounted on top of each other due to space issues. I started with one but it wasn't enough, you can parallel these as many as you need)
_MG_2513-crop.jpg

Two 26AH batteries under a seat
IMG_111943615.jpg

Custom made bracket from aluminium to clamp down batteries. Tapped together mostly with M4 & some M6 bolts and Nyloc nuts where appropriate.
IMG_3232-battery.jpg

One of my 26AH gel batteries which needs to move within the car. It is tied down. Two 50 amp Anderson plugs on the side to plug in load & charging. Velcro handle.
26Ah-battery.jpg

I have two 9 amp DC-DC chargers (old model which are not smart charging) & a MPPT 20/100 bluetooth solar controller.
 
Looking at the manual for the mentioned 299 watt battery station. Charging is 3.2 amps. So it's probably trying to get away without a proper BMS.

A lot of these cheap battery packs are made up from C grade 18650 cells.
 
Don't waste your money on these pre made battery packs. They have a cheap battery, undersized, plus things you don't need.

I actually liked the idea of having an AC adapter and some USB outlets. In my opinion, it makes it more versatile. I was looking at some more batteries today and I guess I could just buy a separate inverter and USB adapters. My main draw to the premade batter packs is not having the leads of the batteries exposed. I could prevent that with the types of batteries you're suggesting with some shrink wrap or electrical tape.

Buy an AGM or gel battery or batteries to fit the available space in the car and a DC-DC charger.

I don't think I'm going to be able to fit any batteries under my car seats except for the Cellink ones which I'm already leaning away from. I would need to buy a DC-DC charger even with the pre-made packs if I planned to do any type of charging off the alternator/starter battery.

With lead acid in general aim to only use 50% of its AH before recharging. Every now and then a heavy discharge is ok but charge up ASAP.

The only problem with using a lead battery is that I'm driving my car less and I'm getting less and less time in parking mode. Having to drive my car around for the sake of charging up the lead acid battery defeats the purpose of a separate battery pack for my use case. The only benefit it gets me over using the starter battery is that I'm not impacting the life of the starter battery.
 
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Looking at the manual for the mentioned 299 watt battery station. Charging is 3.2 amps. So it's probably trying to get away without a proper BMS.

I was looking at Dakota Lithium batteries and I came across this on their website:


"Dakota Lithium has optimized this charger for use with our lithium iron phosphate batteries (LiFePO4). All 12 volt Dakota Lithium batteries should be charged using a LiFePO4 compatible charger like this one. SLA chargers will reduce the performance and lifespan of the battery. This charger charges at a speed of 3 amps an hour and is optimal for batteries < 25Ah. For batteries greater than 25Ah like the 54Ah or 100Ah battery we recommend the 10 amp charger."

The charger was linked from their 12V 23Ah / 295 Wh LiFePO4 battery listing page which lists it has a BMS:

"Includes active BMS protection

Contains a circuit that handles cell balancing, low voltage cutoff, high voltage cutoff, short circuit protection and high temperature protection for increased performance and longer life."

I don't know much about battery systems, but from my limited knowledge and research it doesn't seem like the charging amps is a good way to determine if it has a good BMS. The listing for the GOLABS pre-made pack does mention a BMS despite the weird/awkward wording:

"GOLABS power supply works without bothering noise, no fuel or gasoline, it can safeguard you and your devices by over-voltage protection, over-current and over-temperature protection.

Battery Management System (BMS) can continue to escort you. You can use with confidence"


A lot of these cheap battery packs are made up from C grade 18650 cells

I tried to find out what C grade meant. Are you referencing a UL battery grading system? The only other thing I could find was some reference to how well they maintain the voltage, but the website I was reading said C grade isn't something to worry too much about. For the 18650 cells, are you saying that the battery may actually be Lithium Ion instead of LiFePO4?

If I went with the Dakota Lithium 23Ah/295 Wh battery, then it would run $229 USD, based on the website pricing. If I bought their inverter and USB phone charger to get similar capabilities, it would add $139 and $29 respectively to the price. Overall, I would probably looking at an extra $160 for the Dakota Lithium setup to get similar capabilities to the GOLABS device. I guess one benefit to having the inverter and USB phone charger separate is I can replace the devices separately if they fail, instead of having to replace the entire pre-made pack.
 
You will have to drive around for the starter battery. During lockdown we can go weeks without driving the car so I charge starter & auxiliary batteries with a smart charger.

A 23AH battery with a 300watt inverter. Rule of thumb, watts/10 for inefficiencies, so 300/10 = 30amp, 23x0.8/30x60min = 36minutes. Obviously if charging an electric toothbrush you have longer.
 
Stupid question, do I have to connect a dc/dc charger directly to the starter battery terminals or can I just connect it to the fuse panel inside the car?

How do I connect the dash cam to the LIFEPO4 battery? Do i just have some type of terminal block connected to either the battery that the dash cam can feed off od?
 
You can't connect the DD-DC charger straight to the starter battery or it will drain the starter battery as it will constantly charge.

You can connect it to an accessory fuse that is only powered when the engine is running, but it would be best that the fuse rating is twice the AH rating of the DC-DC charger.

If the you haven't got a fuse double the power you need. Use a relay so the accessory circuit switches on the relay, and then a power supply from the starter battery via the rely powers the DC-DC charger. Easy.

The same as adding some spot lights.

Put a fuse at beginning of the cable running from the battery. Make sure the cable is tied in place carefully so it does not rub on anything. If you are really good wrap the cable in some Tesa 51036 engine bay tape or similar. Heatshrink connectors.

It is not difficult, just plan it out carefully. Do it properly once!
 
If you go with a LiFePO4 device like this be sure it also has low-temp protection (as in seeing a teardown video w/ an actual test). Many claim low-temp protection but few actually have it. Just one charge attempt below freezing will completely destroy the battery :eek:

I recommend checking out "DIY Solar Power with Will Prowse" channel on YouTube to learn more. There's a link to his website in the channel description.

Much simpler to add AGM, but one of these "solar generators" can do well and offer the extras you want, plus could be removed and used elsewhere if needed ;)

Phil
 
victron energy earlier this year finally released information about the importance of sizing of lifepo4 to alternator for direct charging off it no dc to dc converter needed blowing the myth out the water of alternator damage if done correctly.....

technically conected like this the lifepo4 at 13.2v normal working voltage would keep the lead acid at this fully charged and trickle charging it and your cameras could run as you please.... lol you could even get creative and pre heat electric seats or a 135w tube heater on a timer or sump oil heater...
possibilities are endless lol

a 100ah is 6x6x8 inches and youd be adding 3 times useable capacity of your car battery that charges from flat in 2.5 hours driving///
 
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Ok, so I think I'm getting closer to pulling the trigger. Initially I was targeting a 50 - 60AH batter, but now I think I'm going to go with a 100AH battery. I believe this will give me 1280WH (100AH x 12.8V) from reading various threads on here. Assuming a 5WH draw from the A129 Pro Duo and 5WH from a MT1, that I want to install on in the future for my side mirrors, this gives me roughly 128 hours of run time without charging which is roughly 5.33 days.

The only hiccup is the wiring part. The normal add-a-circuit fuses are rated up to only 10A. I searched Amazon and found some that would be good for 20A. I thought this would cover a 18A DC-DC charger, but @Outbacknomad is saying to use a fuse rating twice the AH rating of the DC-DC charger which would be a 40A fuse and I'm not sure they make a 40A fuse tap or if my fuse panel is even rated up to 40A. The highest amp fuse I see in it is a 30A fuse for the windshield wipers. If I put in a 40A fuse, then that means I should run wire that is able to handle 40A, right? This seems like a lot thicker cable than I had originally planned on running that was rated for 20A.

If I can't find a fuse tap rated for 40A, but my fuse box can handle that, then I'm thinking I might be able to use an empty fuse slot. I would just need to find out which connector corresponds to the empty fuse slot, crimp/solder a contact, and insert it into the connector. However, this assumes that a cable rated for 40A would fit in the connector.

I'm thinking I could figure out where the empty fuse slots go by using a multimeter to do a continuity check on the non-energized side of the empty fuse slot and probing the empty slots on the connectors.

Here's some photos of my fuse panel so you can see some of the empty pin/cable slots on the connectors:

fuse-panel-cables-and-connectors.jpg

fuse-panel-fuses.jpg

I'm leaning pretty heavy towards ExpertPower's EP12100 100Ah LiFePO4 battery. I searched for a tear down video as suggested by @SawMaster and found a video by Will Prowse tearing down and testing the EP1200:


He said he doesn't recommended because it failed his low temperature charging cutoff test. However, he posted some emails from ExpertPower where they acknowledged the problem and are working to correct it. I didn't see any updates in the comments as to whether the batteries now have a functional low-temp protection, but at a price point of $560.99 I'm tempted to purchase one anyways. I guess I would have to pay attention more to make sure I wasn't charging it in low temperatures. I did find an interesting comment:

"Awesome review. Thanks. Get some sleep! It looks like they use some grade B/C cells that didn't pass 75Ah mark of the manufacturer, and were sold as sub 75Ah cheaply to them. Then they did capacity matching and put ~110Ah in pairs. No other explanation possible I think. It wouldn't be so heavy otherwise. Rest looks okish."

I'm not really sure how much the cell grade matters if the battery outputs the required wattage. Also, Will mentioned the battery is not capable of charging/discharging at the a full 100Ah, but that's totally fine given my use case.

You can connect it to an accessory fuse that is only powered when the engine is running, but it would be best that the fuse rating is twice the AH rating of the DC-DC charger.

Why does this fuse need to be twice the AH rating of the DC-DC charger?

If the you haven't got a fuse double the power you need. Use a relay so the accessory circuit switches on the relay, and then a power supply from the starter battery via the rely powers the DC-DC charger. Easy.

I'll have to look into this as I'm not familiar with relays. I guess a lot of this hinges on me figuring out the max amps my fuse panel is rated for.

victron energy earlier this year finally released information about the importance of sizing of lifepo4 to alternator for direct charging off it no dc to dc converter needed blowing the myth out the water of alternator damage if done correctly.....

Do you have a link to a video? I found a video where they talk about some alternators can output full loads at max RPMs and when they halved the RPMs the alternator started smoking. Their recommendations were installing an alternator that can handle the loads at low RPMs, fit a regulator and temperature sensor, or use a current limiter or DC/DC charger. Also, they mentioned something about some lithium battery systems disconnecting the battery from the charging source once fully charged potentially damaging the alternator. The recommended a Buck Boost and a DC/DC charger to avoid this:


a 100ah is 6x6x8 inches and youd be adding 3 times useable capacity of your car battery that charges from flat in 2.5 hours driving///
The ExpertPower one is 13 x 6.8 x 8.4. With an 18A DC-DC charger it seems like it would fully charge from flat with a little over five to six hours of driving which is pretty close to how long I would drive it when I'm using my car to go to work every day. I was thinking I could even just buy a 10Ah battery to swap in if I ever needed to pull the 100Ah one out to charge in the house. I think the 10Ah would be enough to cover the in-house charging time of the 100Ah battery.

Finally, I need a way to secure the battery. I was looking at some battery boxes at Wal-Mart and found one that would fit the ExpertPower battery. It has a strap to secure the case. I noticed in my trunk there's an anchor point to secure a child's car seat. It seems like I could thread the batter box strap through it and it would be fairly secure in the event of an accident. The battery box would also help prevent any inadverent contact with the battery posts.
 

this is gospel... 12 minutes in

used this method 2 years and maximum a 100ah battery has demnanded is 65a when flat

lithium is very easy to set up and forget abouy bar a quick glance at state of charge ...
 
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Will very recently reviewed a 100A LiFePO4 with low and high temp cutoff using cells and a BMS he's familiar with and approves of for about $350 on Amazon- if they're not sold out. That usually happens when he recommends a product. SOL brand is one of his long-term favorites too but a little pricier. If the Victron charge controller being discussed has low-temp protection and is mounted in the same area as the battery then you don't need that functionality in the battery too.

Phil
 
Will very recently reviewed a 100A LiFePO4 with low and high temp cutoff using cells and a BMS he's familiar with and approves of for about $350 on Amazon- if they're not sold out. That usually happens when he recommends a product. SOL brand is one of his long-term favorites too but a little pricier. If the Victron charge controller being discussed has low-temp protection and is mounted in the same area as the battery then you don't need that functionality in the battery too.

Phil

I checked and they’re already sold out. He did leave a follow up comment saying they still haven’t emailed him back and what good is it to have a 10 year warranty if you can’t contact them. I guess their only presence is Amazon or something

I’ll have to check out that other battery. I’m going to try to make a decison by the end of the week otherwise I’m just going to keep putting it off.

I paid $20 for 1-month access to my car’s service manual at AllData. The big white wire in the photo feeds that fuse panel. It comes from the engine compartment junction/fuse box and is fused on the engine compartment side at 40A.

This made me think it’s probably not a good idea to run the DC-DC charger off the fuse box in the passenger compartment. The last thing I want to happen is to be driving down the road, pull too many amps using the dc-dc charger in conjunction with everything else on the passenger cabin fuse box and blow the 40A fuse. I believe the Victron dc-dc charger allows you to wire in a signal wire to cause it to shut off. If I ran a wire connected to ACC, then I don’t have to worry about draining the starter battery.

I found some threads on some other websites where the Victron 12/12 18A DC/DC charger blew a 20A fuse. They were theorizing that a 25A fuse might be sufficient, but even if the max draw is somewhere between 20 - 25A that doesn’t leave much room for all the other stuff which is pulling power.

To be honest, I’m not too excited about routing a cable through the firewall. The penetrations seem to be fairly high up on the firewall which means I’m most likely going to have to take the dash apart to get access to route the cable.

I’m probably going to do this in stages as to not get overwhelmed. I figure I can buy the battery, install it, and run a temporary cable to power the dash cam directly with the 100Ah battery. I can remove it on the weekend to charge and swap in a 10Ah battery to power the camera while the larger one is charging. This will get me the parking mode coverage I want and take the dash cam off the starter battery.

I can then work out the logistics of getting the right sized cable to run to the battery, watch cideos of taking the dash apart, etc. I think this is something that is commonly done with amplifier installs. I’m pretty optimistic on finding some good YouTube videos. If not, I have the service manual which should make taking the dash apart a lot easier.
 
The penetrations seem to be fairly high up on the firewall
That is normal but means that they are easily accessible from the engine compartment. Push a stiff wire / fence wire through from outside and you can probably find it on the inside without disassembling much, then tie your cable to the wire and pull through. Can end up really easy.

If you use ACC to switch an automotive relay then you don’t need to worry about drawing too much current. That is also easy.
 
I thought choosing a dash cam was hard, but deciding on a battery seems harder. A lot of the batteries recommended on Will Prowse’s YouTube channel were either sold out, long lead times, didn’t ship to my location, or had really expensive shipping to my location.

In the end, I went to a battery shop local to me and bought a small 9Ah liFePO4 Bioenno Power battery which is what they had in stock. I purchased a Dakota 3A LiFePO4 battery charger as well. The Bioenno instructions say to use a 2A charger. I’m assuming the battery place wouldn’t have sold me a charger that would wreck the battery, but I guess I’ll find out.

The Bioenno has some limitations, but it gets me started and will help me increase my parking mode coverage for the weeks I’m not driving as much. I had to remind myself that my goal was to increase the parking mode coverage and a great battery/deal was only secondary. It doesn’t have the low temp charging cut off and they don’t recommend wiring it in parallel or series wirh other batteries, but I can live without those things. There’s most certainly other options with more bang for my buck, but this was most readily available to me.

I thought about purchasing two 9Ah batteries to be able to have one in the car and one in the house charging. However, I decided to see how the one battery works out. Also, this would give me time to research 100Ah batteries and potentially put the money towards a 100Ah battery instead of just buying another 9Ah battery. If I end up buying a 100Ah battery, then I can swap in the 9Ah battery if I ever need to bring the 100Ah in for charging.

For every other week I work from home I probably will only have to run the engine once for five minutes, if that. Currently the starter battery routinely powers the camera for 15+ hours before the cutoff voltag is reached. I believe yesterday/today it lasted for about 22 hours.

Worst case scenario, I know running my car for five minutes gives the starter battery enough charge above the HWK cutoff voltage to allow my dash cam to run 3 - 4 hours while the Bioenno is charging inside the house. This does mean making two trips to my car each day to grab the battery for charging an to re-install it afterwards, but I’m not too worried about that. It will just mean I get some extra steps in every day.

I’m going to try to wire the Bioenno in such a way that I can easily switch the dash cam back to the starter battery when I remove the Bioenno for charging. This brings me to my wiring questions.

When I wire the LiFePO4 battery to the dash cam, do I just connect the positive battery terminal to the batt+ cable of my Hk3 hardwire kit and negative battery terminal to any ground point on my car or do I need to connect the negative battery terminal directly to the ground cable of the hk3 hardwire kit?
 
That is normal but means that they are easily accessible from the engine compartment. Push a stiff wire / fence wire through from outside and you can probably find it on the inside without disassembling much, then tie your cable to the wire and pull through. Can end up really easy.

I ended up finding the passenger cabin side of the firewall connection. It’sabove and to the left of the clutch pedal. I won’t have to take the dash apart after all if I end up going that route in the future.
 
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