Lithium vs Lead Acid

[ArthurB]

Hi Stormjp

Did you mean to say Tentco? How much do they charge for the ammo box you used?

I like the fact that the bms is bolted to a metal surface that will conduct heat away from it.

My effort as well. Also used Lithium Batteries SA new 100AH cells. Built all into an ammo can from Tentpro. WRND DC-DC charger also fitted in there. Did a 4500km roadtrip and it functioned flawlessly! All in all I'm super happy with the setup

[Rooikop]

I am pretty sure that I will be able to fit another 4 cells, to up the battery to 240 A/h, using a combination of series and parallel links between the cells. But I am not brave enough for that yet!

Very nice, smartly put together. Those ODW boxes do fit 8 cells, I built 2 of them as can be seen from my post #148. And you have most of your gadgets on the lid already, should be a walk in the park.

[stormjp]

Hi Stormjp

Did you mean to say Tentco? How much do they charge for the ammo box you used?

I like the fact that the bms is bolted to a metal surface that will conduct heat away from it.

Hi ArthurB

It was definitely from tentpro. You can have a look on their website, tentpro.co.za. I used the 50Cal ammo box, which cost around R400 if I remember correctly.

All in all, I have had zero issues thus far and super impressed with the Lifepo4 batteries.

[hatjohan]

Hi Stormjp

Did you mean to say Tentco? How much do they charge for the ammo box you used?

I like the fact that the bms is bolted to a metal surface that will conduct heat away from it.

I do not experience significant heat *(actually, hardly any) at the BMS (or cells) during charging or discharging

[hatjohan]

Very nice, smartly put together. Those ODW boxes do fit 8 cells, I built 2 of them as can be seen from my post #148. And you have most of your gadgets on the lid already, should be a walk in the park.

Was their room for any material eg double sided tape or thin sponge, between the cells, just to prevent chafing?

[Robbief]

OK, as promised.
Please critique my effort.

I used 4 "new" cells from LithiumSA @ R6 547, including the BMS, some cabling and lugs.
Installed in a battery box from Outdoor Warehouse @ R379
On/Off switch and fuse box from 4x4 Direct @ R355 and R350 respectively
Some odds and end from my own "Builders Warehouse Light" toolbox.

Sorry, add to that the sockets (Hella, USB and Cigarette and Voltmeter (NL)) that I also got from ODWH - that was quite a few bucks!

Yes, that is an 5l upside down ice cream bucket that you see. It acts as a placeholder - I am pretty sure that I will be able to fit another 4 cells, to up the battery to 240 A/h, using a combination of series and parallel links between the cells. But I am not brave enough for that yet!

Attached Thumbnails


Thanks to Wedwo, Tron, Gerlach, Kortgat, Rooikop, Ekkekan, Dungbeetle and All the others that gave me the courage and the knowledge, to do this!

As usual I really like the name tags. well done Johan, that battery box is professional.

[BruceHun]

Nicely done. I took the easy way out and got a secondhand/new NL battery box for R1800 and installed a 108ah blue nova battery that was on dealer special for R6650 ex vat.

[Rooikop]

Was their room for any material eg double sided tape or thin sponge, between the cells, just to prevent chafing?

I placed some thin cardboard between some cells. But to keep the hole lot from moving to much I bound them together with duct tape. There was hardly any movement when they went into the box.

[Snyks]

So is there no 8 cell, 12v BMS available or will the BMS see the two parallel connected cells as a single cell? Will it be able to balance the two cells as effectively as a BMS would a single cell?

[hatjohan]

So is there no 8 cell, 12v BMS available or will the BMS see the two parallel connected cells as a single cell? Will it be able to balance the two cells as effectively as a BMS would a single cell?

Have a look at what Rooikop did Post #148.

Somewhere there is a diagram of connecting the cells.

[JLK]

Also used Lithium Batteries SA new 100AH cells. Built all into an ammo can from Tentpro. WRND DC-DC charger also fitted in there. Did a 4500km roadtrip and it functioned

Does that mean a normal DC-DC charger from the alternator is fine to use to charge these LiFePO4 batteries, if I change to LiFePO4? My solar controller and 230V charger are from Victron.

[the_terrible_triplett]

I'll just post this video here again ... I nearly did it ...

[Snyks]

Have a look at what Rooikop did Post #148.

Somewhere there is a diagram of connecting the cells.

I don't think you read my question

[Dungbeetle]

So is there no 8 cell, 12v BMS available or will the BMS see the two parallel connected cells as a single cell? Will it be able to balance the two cells as effectively as a BMS would a single cell?

2 cells in parallel auto balance with each other. And a BMS sees them as one cell.
Balancing between twice the size "cells" then in series will take double the time....

[stormjp]

Does that mean a normal DC-DC charger from the alternator is fine to use to charge these LiFePO4 batteries, if I change to LiFePO4? My solar controller and 230V charger are from Victron.

Hi JLK

I Installed a DC-DC charger in my battery box, fed from a cable running directly from the vehicle battery and to date it has functioned flawlessly. Everything has been fused properly, as im scared of overheat/shorts!

Im sure the experts will be here shortly to give advise and I'll then have to change my system to prevent my vehicle from burning to the ground.

[JLK]

Hi JLK

I Installed a DC-DC charger in my battery box, fed from a cable running directly from the vehicle battery and to date it has functioned flawlessly. Everything has been fused properly, as im scared of overheat/shorts!

Im sure the experts will be here shortly to give advise and I'll then have to change my system to prevent my vehicle from burning to the ground.

Thanks . Lets see. Google is clear on solar controllers and battery chargers, alternators etc, but could not get clear answer on DC-DC chargers.

[hatjohan]

I don't think you read my question

Sorry, just trying to be helpful, and I did read your question but did not had the time to search for the specific post with diagram. As far as I know LitiumSA can provide you with a diagram to do just what you ask, without a 12V 8 cell BMS.
The photo of the setup should actually be of great assistance - on how to combine a 12v 4 cell BMS with 8 cells.

[Snyks]

Sorry, just trying to be helpful, and I did read your question but did not had the time to search for the specific post with diagram. As far as I know LitiumSA can provide you with a diagram to do just what you ask, without a 12V 8 cell BMS.
The photo of the setup should actually be of great assistance - on how to combine a 12v 4 cell BMS with 8 cells.

Dungbeetle answered my question. I have built a 4 cell 12v unit with 4 cell BMS. My question arose when I saw the guys using the very same 4 cell BMS. I looked for 8 cell 12v BMS but could not find, hence my question.

[Kortgat]

I'll just post this video here again ... I nearly did it ...

Think this video is a bit misleading though. The test is done with Lifep04s without a BMS. With a BMS I cannot see the problem, especially if the BMS charge rating is reasonably within range of what the alternator is capable of. I do charge mine straight off the alternator, no issues.

[stormjp]

Think this video is a bit misleading though. The test is done with Lifep04s without a BMS. With a BMS I cannot see the problem, especially if the BMS charge rating is reasonably within range of what the alternator is capable of. I do charge mine straight off the alternator, no issues.

Anything can be dangerous if you decide it to be. Trying to maintain a constant 90Amps from an alternator at idle revs would be 'stupid'. Let alone bringing cable thickness into the equation. It is easy, and annoying, when people remove all the safety measures and make it out that the worst will happen if you don't do it their way.

Sometimes a little common sense goes a long way.

As I said, Im no electrician, but I did my due diligence and think my setup is working well and safe.

Max amps into my 2nd battery with the DC-DC will be 20 amps and only after the primary battery is fully charged.