SOK 206AH battery installation

[hbn7hj]

I replaced two 100AH Battleborn batteries with two SOK 206AH batteries. The footprint is not the same and they are a little taller but I had the room.

The Battleborns arrived fully charged 6 years ago. The SOK batteries arrived depleted. It takes a long time to charge 412AH from a generator. SOK would like the charge rate to be 40 amps per battery. I charged at 90 amps total for almost four hours by generator to a charged voltage of 14.3 volts.

The Battleborn weight was 28lbs each. The SOK spec is 48lbs each.

I paralleled them with two remaining healthy 100AH Battle born batteries. Each bank has it’s own battery monitor so I will let you know how that works. If it does not work I can separate them but I expect it to work. I’m expecting a total charge rate of 150 amps. Will let you know what it turns out to be when I get back on the road in July.

The second battery compartment cannot handle two SOK 206AH batteries.

The next job is to install the Velit high altitude furnace. I’ll test it at 10,000 ft in August. The Webasto works so very well below 5000ft I hate to take it out. It won’t last a week at 10,000ft.

[MsNomer]

We hope to install our VeLit when we get home from the current trip in June.

[booster]

Originally Posted by hbn7hj

I replaced two 100AH Battleborn batteries with two SOK 206AH batteries. The footprint is not the same and they are a little taller but I had the room.

The Battleborns arrived fully charged 6 years ago. The SOK batteries arrived depleted. It takes a long time to charge 412AH from a generator. SOK would like the charge rate to be 40 amps per battery. I charged at 90 amps total for almost four hours by generator to a charged voltage of 14.3 volts.

The Battleborn weight was 28lbs each. The SOK spec is 48lbs each.

I paralleled them with two remaining healthy 100AH Battle born batteries. Each bank has it’s own battery monitor so I will let you know how that works. If it does not work I can separate them but I expect it to work. I’m expecting a total charge rate of 150 amps. Will let you know what it turns out to be when I get back on the road in July.

The second battery compartment cannot handle two SOK 206AH batteries.

The next job is to install the Velit high altitude furnace. I’ll test it at 10,000 ft in August. The Webasto works so very well below 5000ft I hate to take it out. It won’t last a week at 10,000ft.

Yep, that should be interesting. The SOK look to be very good batteries but with really low charge rates for being 206ah. It appears to be because SOK uses the same BMS in the 100 and 206ah batteries so the BMS is undersized in the larger battery.


There is currently a bit of confusion on Current Connection site related to charge rates when comparing to the SOK site. All the batteries used to 40 recommended and 50 max charge rate, but now the 206ah batteries, some anyway, say they are 70 max charge rate on the SOK site. The pix on site show 50 on the batteries however. On the Current Connection site they have a pic of the alleged new Bluetooth BMS for the 100ah battery and it says 70 max on it. My guess it the Bluetooth BMS is 70 amps and the non Bluetooth one is still 50 amps.


If you got the steel cased batteries, you can open them up and see the BMS and it will say how much the ratings are. The 206ah battery cells should certainly handle 70 max if the the 100ah can handle 50.


The non bottom basement brands of batteries seem to be going to lower charge rates very quickly so the advantage of high rate charging is going away. .4 to .5C rates are getting to be the norm and good AGMs can be charged at .4C pretty easily. The advantage now with lithium charging is getting to be only in the top 15-20% of charging where AGM acceptance drops quickly.

[MarCorpsMustang]

You parallel connected two 100Ah batteries with two 206AH batteries? I always thought that was bad juju.

[hbn7hj]

We will see. Each bank has it’s own battery monitor. I’ll let you know how or if it works.

I expect it to work but if it doesn’t I can pop a circuit breaker and use each bank separately.

[MarCorpsMustang]

My guess is you'll get 400Ah out of the combined four batteries. The combined pair of 100AH batteries will produce 200Ah and the combined pair of 206Ah batteries will also produce 200Ah (vice 412Ah) due to being limited by the lower-capacity pair of the paralleled 100Ah batteries. I'm eager to see your results.

[booster]

Originally Posted by MarCorpsMustang

You parallel connected two 100Ah batteries with two 206AH batteries? I always thought that was bad juju.

I think the connection of multiple lithium batteries is more related to them being in series, not parallel. Several have started recommending add on battery balancers for series use, like are used with lead acid batteries.



IIRC it has something to do with the ability of the auto cell balancing to work correctly.

[MarCorpsMustang]

Originally Posted by booster

I think the connection of multiple lithium batteries is more related to them being in series, not parallel. Several have started recommending add on battery balancers for series use, like are used with lead acid batteries.

IIRC it has something to do with the ability of the auto cell balancing to work correctly.

I don't claim to be correct, but I suggest that the auto cell balancing ability of LiFeP04 cells is exactly what will cause the pair of 206Ah batteries to limit their output to a combined 200Ah if paralleled with the pair of 100Ah batteries. Looking forward to the OP's observations.

[hbn7hj]

I’ll let you know next month. Fully charged there is no difference. What each bank looks like after withdrawing 100AH is what will be interesting. Also how they charge.

I have the instrumentation to observe. Can you withdraw 500AH with them combined? I don’t know but I expect so.