Alternative battery pack

m12volt

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By looking at the prices for Battery Packs I thought that it has to be an alternative solution.
How about using a Portable Sealed AGM Battery to run a Dashcam on Parking Mode ?
Has anyone tried this ?

https://www.ebay.com/itm/152284621267
 
AGM batteries work fine but not ideal setup for most cars. You need a charger and find space to put the battery.

Their energy density is low compared to Lithium cells making them big and heavy. It also cant do full discharge cycles like a LiFePo4 cells on the Cellink B, so i would go for a 35Ah at the very least.

Its hard to beat the Cellink B because its got the ideal battery type and it integrates to the car so well with very little messing around.
 
The only problem with Cellink is a price , I have enough room for a small AGM battery , I think it would be charging when connected to any 12v ignition power source too. I am not sure how long it would work feeding 2-ch Blackvue , but 22Ah should be enough to keep it in parking mode overnight with Wi-Fi off
 
I think it would be charging when connected to any 12v ignition power source too

Its a crude way of charging and will never charge an AGM to 100% SoC. A DC-DC mutli-stage charger is the ideal way of charging AGMs which costs a fair bit.

22Ah should be enough to keep it in parking mode overnight with Wi-Fi off

22Ah is the 100% discharge rate, the AGM will not live very long if you cycle it like this.

Have a look at the spec sheet for a typical AGM battery. If you look at the chart "Cycle life in relation to depth of discharge", you will see that if you discharge it 100% its expected to only last 300 cycles compared to 1600 cycles if you only discharge it 30%.

I've got a dual battery AGM setup on my car (100Ah) and i can tell you now to do it properly will cost a lot more than a Cellink.
 
I see , so may be a regular sealed battery from the link above would work better ?
 
Also keep in mind that AGM batteries have a different charge cycle than SLA or other batteries. You may need a dedicated DC-DC charger that supports AGM batteries.
 
I see , so may be a regular sealed battery from the link above would work better ?

Its the same battery (SLA/VRLA). AGM is still a sealed lead acid battery just has fiberglass matting inside.
 
I think you are referring to Gel Cell. The AGM is another battery type and is sensisive to overcharging:

http://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

Nope, AGM and GEL are types of SLA batteries. Its just how the acid is stored between the plates keeping them from leaking out.

They do have differing characteristics but at the end of the day its still a lead acid battery.

And batteries labelled as deep cycle just has thicker plates. This can come in flooded, gel or AGM.
 
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Wet cell (marine type) deep-cycle batteries handle deep discharges the best because the liquid dissipates the heat from the plates better, but no rechargeable battery likes being over-discharged and with some (LiIon) that can even be dangerous (LiIon almost always has over-discharge protection built-in because of that). The starting battery in my ancient van is huge compared to the minimal designs used now and on the few occasions where I forgot to turn my cams off it has supported 4 cams parked overnight with no problems. So I am of the mind that any battery technology is OK here so long as it's sized correctly, charged correctly, and not over-discharged. And I like simple but effective systems best :) If you will be certain to not leave it on too long (over-discharge) then a wet-cell deep-cycle is simplest of all to charge: just tap directly to the car battery via a relay which connects only when the car is running (charging) pr commercial battery isolater and run your cams off of that, No it isn't optimal but it's good enough. The downside is that these wet-cell batteries emit explosive hydrogen when being charged so they must be ventilated safely. SLA is very similar but avoids those gasses so that is what I'd recommend to others for a large DIY system ;) My own 'ideal' system will be a relay-isolated wet-cell deep discharge battery because I've got space to install a huge one and I have other things I want on my system, not just my cams :cool: Amp for amp, it's the cheapest way to get what I want and I'll monitor the voltage manually to not over-discharge it.

Most folks don't want to fool with all that so they use powerbanks or something like Cellink that is similar but designed expressly for this use. It's essentially almost plug-and-play making things super-easy and you've got the support of others here who know the devices inside and out plus you get a warranty. For most here that is the best solution of all :D

Phil
 
I think all I need would be SLA battery connected to vehicle ignition for charging and Power Magic Pro to monitor over discharge.
I would consider a small charger if Ignition power would not charge it properly or over-charge
 
Do keep in mind the amount of current it will need as it charges; you will need to tap in somewhere that can handle it plus the original load. You also need to keep in mind that the 2nd battery will be feeding power back into that circuit even when the engine is off. At the least this will draw some power from the 2nd battery and could possibly screw up some of the car's electronics :eek:

This is why I suggest using a relay as it eliminates the potential for problems in both areas ;)

Phil
 
Yes , I think You're right about a relay , as for charging I am not sure if it would charge properly or would need a small intelligent charger
 
Very nice ! Definitely worth $50 , in combination with 20Ah SLA battery would do exactly what I need for a total cost of about $100
 
These were great help to me. I am looking at a 12v 12ah SLA with AGM technology as anything bigger is too big in size. I would enjoy the LifePo4 but I don't want to invest the money for that but may in the future come up with a better kit on my own. I am an engineer.. electrical with a lot of experience in different areas but of course I can miss something. I try to think simple when I can. I like the link about powerstream and the cut off and all.

+1 for Powerstream, but try this one out:

http://www.powerstream.com/d-sine-dc-ups.htm

If you want to use your own battery, use this one:

http://www.powerstream.com/DC-UPS-1212.htm

I also like this here:
Or if I use this 12Ah SLA battery it would still give me 144wh which is double capacity of Cellink for only $75 incl. charger

https://www.ebay.com/itm/291830531509

I have laid out a basic schematic here and I am using an F770 which has an internal cutoff if the voltage drops too far.
So if I usa a 12v 12AH SLA/AGM I should get 30+ (about 33 assuming 80% efficiency and nominal 12v though if higher then the hours would go up), hours given then F770 with a rear camera draws 3.5Watts according to the docs. Now.. if I toss a relay (12V 30/40 amper) on a accessory fused line with add a circuit.. like the radio.. I can disconnect the aux battery while the car is off and and not drain the main battery. When I start, the car the radio shuts off and thus disconnects, or at least I need to check that it does for sure and not just a control signal, and thus the aux battery is not being used to start the car. But after it starts, the battery reconnects via the relay and it charges again.

The F770 dashcam will turn off after whatever voltage I set as it is wired to the aux battery.. and the car is off so the relay is off so when the F770 shuts off then no problem. Thus I dont need anything fancy I think. $5 relay and a SLA from what I can see. Cellink B too pricey and only good for 18 hours maybe.. and for another $200 or something you get 40 hours woohoo. I have spent a lot of time researching but still hard to spend $400 for 40 hours of parking mode.

Summary:
Acc connects to the relay and the F770. The relay shuts off when the car is off and when starting.. ideally.. and I will make that work. The F770 shuts off when the aux battery hits the lowest level. I can set it down to 11.8 Volts or less and not have to worry about it. Start the car and start charging again.

I did this today and it worked. Although that gizmo is pretty cool to disconnect and all.. its just already built into the F770. If you dont have that then of course you need that item or one of the other voltage or time controllers. I had let my battery accidentally get down to 9.6 volts while testing and ya it was dead but the F770 was still running.

This can be refined I am sure but I thought it is worth a test. The $50 setup from powerstream is great, but I dont need to draw from the main batteries while the car is off.

This does work for me at least and I verified the radio fuse shuts off on crank.. and the auxiliary battery is independent of the main battery when the key is off. The battery cost me $34.95 + tax.

Hope this helps someone.

Cheers.
 
These were great help to me. I am looking at a 12v 12ah SLA with AGM technology as anything bigger is too big in size. I would enjoy the LifePo4 but I don't want to invest the money for that but may in the future come up with a better kit on my own. I am an engineer.. electrical with a lot of experience in different areas but of course I can miss something. I try to think simple when I can. I like the link about powerstream and the cut off and all.



I also like this here:


I have laid out a basic schematic here and I am using an F770 which has an internal cutoff if the voltage drops too far.
So if I usa a 12v 12AH SLA/AGM I should get 30+ (about 33 assuming 80% efficiency and nominal 12v though if higher then the hours would go up), hours given then F770 with a rear camera draws 3.5Watts according to the docs. Now.. if I toss a relay (12V 30/40 amper) on a accessory fused line with add a circuit.. like the radio.. I can disconnect the aux battery while the car is off and and not drain the main battery. When I start, the car the radio shuts off and thus disconnects, or at least I need to check that it does for sure and not just a control signal, and thus the aux battery is not being used to start the car. But after it starts, the battery reconnects via the relay and it charges again.

The F770 dashcam will turn off after whatever voltage I set as it is wired to the aux battery.. and the car is off so the relay is off so when the F770 shuts off then no problem. Thus I dont need anything fancy I think. $5 relay and a SLA from what I can see. Cellink B too pricey and only good for 18 hours maybe.. and for another $200 or something you get 40 hours woohoo. I have spent a lot of time researching but still hard to spend $400 for 40 hours of parking mode.

Summary:
Acc connects to the relay and the F770. The relay shuts off when the car is off and when starting.. ideally.. and I will make that work. The F770 shuts off when the aux battery hits the lowest level. I can set it down to 11.8 Volts or less and not have to worry about it. Start the car and start charging again.

I did this today and it worked. Although that gizmo is pretty cool to disconnect and all.. its just already built into the F770. If you dont have that then of course you need that item or one of the other voltage or time controllers. I had let my battery accidentally get down to 9.6 volts while testing and ya it was dead but the F770 was still running.

This can be refined I am sure but I thought it is worth a test. The $50 setup from powerstream is great, but I dont need to draw from the main batteries while the car is off.

This does work for me at least and I verified the radio fuse shuts off on crank.. and the auxiliary battery is independent of the main battery when the key is off. The battery cost me $34.95 + tax.

Hope this helps someone.

Cheers.

How are you charging the AUX SLA?
 
How are you charging the AUX SLA?

Hi, I use a relay. it charges from the car alternator. find a circuit like the radio that turns off when the ignition is turned on. Then use that 12v to turn on and off a 12v dc 30/40 automotive relay. Then grab power from say the cigarette lighter. Mine is 20 amp circuit. The wire that feeds that circuit on my car is 12 gauge and will handle up to 40 amps or so.. here is one chart. http://www.powerstream.com/Wire_Size.htm use an add a circuit or whatever your car needs to pick up power.. and feed that to the normally open side of the relay. You can also run a wire direct from the battery which I can do but chose not to. Then take the other output of the relay and run it to your battery. do realize as I found that the more distance the more voltage drop will happen so even though my F770 is set to 11.6 volts.. my battery is behind he passenger seat and is at about 12 volts when it cuts off due to voltage drop and i lose a bit getting to the F770. So keep that in mind.. Also remember to run a large ground to the battery also. I used 12 gauge or 14. i cant remember this moment but I think 14 which is good for 30 amps. I found that i did blow a 15 amp fuse so i put in a 20 for the line to the battery. When you start the car it will disconnect the aux sla battery but then when it starts it will have an inrush current and so far it has not blown my 20 amp fuse.. Sure there are other ways to do this but this was my cheap mans quick way.. later maybe i will do something else but right now $50 for me better than $200+. it is getting at least 12 hours and maybe more but I have not checked.. but if i come out after the night it is still going.. and that is with the rear camera.. but i dont have the security light on to waste watts. if i move the battery closer or Thinkware allowed me to drop voltage down further i could likely get 30 hours out of it. it is not pretty.. with two 14 awg going to behind passenger seat but its only me so I dont really care.. its not a high dollar car so put it in the engine bay or somewhere.. but be aware of the things I mentioned.

I made a schematic on a small paper but tossed after i was done. so.. 18 gauge or less +12v switched with ignition (radio) to +12vdc relay control.. ground to ground of car. switched load normally open one leg to say cigarette lighter.. with 20 amp fuse or 25 but 20 works for me.. then other end to battery.. then battery ground to chassis. 12 gauge at least. if you dont use switched voltage to control the relay.. then it may blow some fuses due to lots of current when starting car.. so please consider what i did.. that is about all i can say here. works for me.. :)
 
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